Merge branch 'apache/master' (4/16/15) into hbase-11339

API conflicts and test fixes
Update LoadTestTool.COLUMN_FAMILY -> DEFAULT_COLUMN_FAMILY due HBASE-11842
Use new 1.0+ api in some tests
Use updated Scanners internal api
Fix to take into account  HBASE-13203 - procedure v2 table delete

Conflicts:
	hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
	hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java
	hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
	hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java

.gitignore

@@ -14,3 +14,4 @@ hbase-*/test
 *.iws
 *.iml
 *.ipr
+patchprocess/

bin/hbase

@@ -34,8 +34,9 @@
 #   HBASE_CLASSPATH_PREFIX Extra Java CLASSPATH entries that should be
 #                    prefixed to the system classpath.
 #
-#   HBASE_HEAPSIZE   The maximum amount of heap to use, in MB. 
+#   HBASE_HEAPSIZE   The maximum amount of heap to use.
-#                    Default is 1000.
+#                    Default is unset and uses the JVMs default setting
+#                    (usually 1/4th of the available memory).
 #
 #   HBASE_LIBRARY_PATH  HBase additions to JAVA_LIBRARY_PATH for adding
 #                    native libraries.
@@ -214,14 +215,17 @@ if [ "$HBASE_LIBRARY_PATH" != "" ]; then
 fi
 
 #If avail, add Hadoop to the CLASSPATH and to the JAVA_LIBRARY_PATH
-HADOOP_IN_PATH=$(PATH="${HADOOP_HOME:-${HADOOP_PREFIX}}/bin:$PATH" which hadoop 2>/dev/null)
+# Allow this functionality to be disabled
-if [ -f ${HADOOP_IN_PATH} ]; then
+if [ "$HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP" != "true" ] ; then
-  HADOOP_JAVA_LIBRARY_PATH=$(HADOOP_CLASSPATH="$CLASSPATH" ${HADOOP_IN_PATH} \
+  HADOOP_IN_PATH=$(PATH="${HADOOP_HOME:-${HADOOP_PREFIX}}/bin:$PATH" which hadoop 2>/dev/null)
-                             org.apache.hadoop.hbase.util.GetJavaProperty java.library.path 2>/dev/null)
+  if [ -f ${HADOOP_IN_PATH} ]; then
-  if [ -n "$HADOOP_JAVA_LIBRARY_PATH" ]; then
+    HADOOP_JAVA_LIBRARY_PATH=$(HADOOP_CLASSPATH="$CLASSPATH" ${HADOOP_IN_PATH} \
-    JAVA_LIBRARY_PATH=$(append_path "${JAVA_LIBRARY_PATH}" "$HADOOP_JAVA_LIBRARY_PATH")
+                               org.apache.hadoop.hbase.util.GetJavaProperty java.library.path 2>/dev/null)
+    if [ -n "$HADOOP_JAVA_LIBRARY_PATH" ]; then
+      JAVA_LIBRARY_PATH=$(append_path "${JAVA_LIBRARY_PATH}" "$HADOOP_JAVA_LIBRARY_PATH")
+    fi
+    CLASSPATH=$(append_path "${CLASSPATH}" `${HADOOP_IN_PATH} classpath 2>/dev/null`)
   fi
-  CLASSPATH=$(append_path "${CLASSPATH}" `${HADOOP_IN_PATH} classpath 2>/dev/null`)
 fi
 
 # Add user-specified CLASSPATH last

bin/hbase-cleanup.sh

@@ -31,7 +31,7 @@
 #   HBASE_SSH_OPTS Options passed to ssh when running remote commands.
 #
 
-usage="Usage: hbase-cleanup.sh (--cleanZk|--cleanHdfs|--cleanAll)"
+usage="Usage: hbase-cleanup.sh (--cleanZk|--cleanHdfs|--cleanAll|--cleanAcls)"
 
 bin=`dirname "$0"`
 bin=`cd "$bin">/dev/null; pwd`
@@ -40,7 +40,7 @@ bin=`cd "$bin">/dev/null; pwd`
 . "$bin"/hbase-config.sh
 
 case $1 in
-  --cleanZk|--cleanHdfs|--cleanAll) 
+  --cleanZk|--cleanHdfs|--cleanAll|--cleanAcls)
     matches="yes" ;;
   *) ;;
 esac
@@ -90,6 +90,11 @@ execute_hdfs_command() {
   "$bin"/hbase org.apache.hadoop.fs.FsShell $command 2>&1
 }
 
+execute_clean_acls() {
+  command=$1;
+  "$bin"/hbase org.apache.hadoop.hbase.zookeeper.ZkAclReset $command 2>&1
+}
+
 clean_up() {
   case $1 in
   --cleanZk) 
@@ -102,6 +107,9 @@ clean_up() {
     execute_zk_command "rmr ${zparent}";
     execute_hdfs_command "-rmr ${hrootdir}"
     ;;
+  --cleanAcls)
+    execute_clean_acls;
+    ;;
   *)
     ;;
   esac	

bin/hbase-config.sh

@@ -126,14 +126,12 @@ export MALLOC_ARENA_MAX=${MALLOC_ARENA_MAX:-4}
 if [ -z "$JAVA_HOME" ]; then
     cat 1>&2 <<EOF
 +======================================================================+
-|      Error: JAVA_HOME is not set and Java could not be found         |
+|                    Error: JAVA_HOME is not set                       |
 +----------------------------------------------------------------------+
 | Please download the latest Sun JDK from the Sun Java web site        |
-|       > http://java.sun.com/javase/downloads/ <                      |
+|     > http://www.oracle.com/technetwork/java/javase/downloads        |
 |                                                                      |
 | HBase requires Java 1.7 or later.                                    |
-| NOTE: This script will find Sun Java whether you install using the   |
-|       binary or the RPM based installer.                             |
 +======================================================================+
 EOF
     exit 1

bin/hbase.cmd

@@ -28,8 +28,9 @@
 @rem
 @rem   HBASE_CLASSPATH  Extra Java CLASSPATH entries.
 @rem
-@rem   HBASE_HEAPSIZE   The maximum amount of heap to use, in MB. 
+@rem   HBASE_HEAPSIZE   The maximum amount of heap to use.
-@rem                    Default is 1000.
+@rem                    Default is unset and uses the JVMs default setting
+@rem                    (usually 1/4th of the available memory).
 @rem
 @rem   HBASE_OPTS       Extra Java runtime options.
 @rem
@@ -87,7 +88,7 @@ if "%hbase-command%"=="" (
   goto :eof
 )
 
-set JAVA_HEAP_MAX=-Xmx1000m
+set JAVA_HEAP_MAX=""
 set JAVA_OFFHEAP_MAX=""
 
 rem check envvars which might override default args

bin/local-master-backup.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 #/**
 # * Copyright 2007 The Apache Software Foundation
 # *
@@ -54,5 +54,9 @@ shift;
 
 for i in $*
 do
-  run_master  $cmd $i
+  if [[ "$i" =~ ^[0-9]+$ ]]; then
+   run_master $cmd $i
+  else
+   echo "Invalid argument"
+  fi
 done

bin/local-regionservers.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 #/**
 # * Copyright 2007 The Apache Software Foundation
 # *
@@ -52,5 +52,9 @@ shift;
 
 for i in $*
 do
-  run_regionserver  $cmd $i
+  if [[ "$i" =~ ^[0-9]+$ ]]; then
+   run_regionserver $cmd $i
+  else
+   echo "Invalid argument"
+  fi
 done

bin/region_mover.rb

@@ -29,7 +29,7 @@ import org.apache.hadoop.hbase.client.HBaseAdmin
 import org.apache.hadoop.hbase.client.Get
 import org.apache.hadoop.hbase.client.Scan
 import org.apache.hadoop.hbase.client.HTable
-import org.apache.hadoop.hbase.client.HConnectionManager
+import org.apache.hadoop.hbase.client.ConnectionFactory
 import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter;
 import org.apache.hadoop.hbase.filter.InclusiveStopFilter;
 import org.apache.hadoop.hbase.filter.FilterList;
@@ -100,7 +100,7 @@ def isSuccessfulScan(admin, r)
   scan = Scan.new(r.getStartKey(), r.getStartKey())
   scan.setBatch(1)
   scan.setCaching(1)
-  scan.setFilter(FilterList.new(FirstKeyOnlyFilter.new(),InclusiveStopFilter().new(r.getStartKey())))
+  scan.setFilter(FilterList.new(FirstKeyOnlyFilter.new(),InclusiveStopFilter.new(r.getStartKey())))
   begin
     table = HTable.new(admin.getConfiguration(), r.getTableName())
     scanner = table.getScanner(scan)
@@ -243,7 +243,7 @@ end
 
 # Now get list of regions on targetServer
 def getRegions(config, servername)
-  connection = HConnectionManager::getConnection(config);
+  connection = ConnectionFactory::createConnection(config);
   return ProtobufUtil::getOnlineRegions(connection.getAdmin(ServerName.valueOf(servername)));
 end
 

bin/region_status.rb

@@ -54,9 +54,9 @@ import org.apache.hadoop.hbase.client.Scan
 import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter
 import org.apache.hadoop.hbase.util.Bytes
 import org.apache.hadoop.hbase.HRegionInfo
-import org.apache.hadoop.hbase.client.MetaScanner
+import org.apache.hadoop.hbase.MetaTableAccessor
 import org.apache.hadoop.hbase.HTableDescriptor
-import org.apache.hadoop.hbase.client.HConnectionManager
+import org.apache.hadoop.hbase.client.ConnectionFactory
 
 # disable debug logging on this script for clarity
 log_level = org.apache.log4j.Level::ERROR
@@ -138,8 +138,8 @@ while true
   if $tablename.nil?
     server_count = admin.getClusterStatus().getRegionsCount()
   else
-    connection = HConnectionManager::getConnection(config);
+    connection = ConnectionFactory::createConnection(config);
-    server_count = MetaScanner::allTableRegions(config, connection, $TableName ,false).size()
+    server_count = MetaTableAccessor::allTableRegions(connection, $TableName).size()
   end
   print "Region Status: #{server_count} / #{meta_count}\n"
   if SHOULD_WAIT and server_count < meta_count

conf/hbase-env.cmd

@@ -24,10 +24,11 @@
 @rem Extra Java CLASSPATH elements.  Optional.
 @rem set HBASE_CLASSPATH=
 
-@rem The maximum amount of heap to use, in MB. Default is 1000.
+@rem The maximum amount of heap to use. Default is left to JVM default.
 @rem set HBASE_HEAPSIZE=1000
 
-@rem Uncomment below if you intend to use off heap cache.
+@rem Uncomment below if you intend to use off heap cache. For example, to allocate 8G of 
+@rem offheap, set the value to "8G".
 @rem set HBASE_OFFHEAPSIZE=1000
 
 @rem For example, to allocate 8G of offheap, to 8G:

conf/hbase-env.sh

@@ -31,14 +31,12 @@
 # Extra Java CLASSPATH elements.  Optional.
 # export HBASE_CLASSPATH=
 
-# The maximum amount of heap to use, in MB. Default is 1000.
+# The maximum amount of heap to use. Default is left to JVM default.
-# export HBASE_HEAPSIZE=1000
+# export HBASE_HEAPSIZE=1G
 
-# Uncomment below if you intend to use off heap cache.
+# Uncomment below if you intend to use off heap cache. For example, to allocate 8G of 
-# export HBASE_OFFHEAPSIZE=1000
+# offheap, set the value to "8G".
-
+# export HBASE_OFFHEAPSIZE=1G
-# For example, to allocate 8G of offheap, to 8G:
-# export HBASE_OFFHEAPSIZE=8G
 
 # Extra Java runtime options.
 # Below are what we set by default.  May only work with SUN JVM.

conf/log4j.properties

@@ -76,13 +76,14 @@ log4j.appender.console.layout.ConversionPattern=%d{ISO8601} %-5p [%t] %c{2}: %m%
 log4j.logger.org.apache.zookeeper=INFO
 #log4j.logger.org.apache.hadoop.fs.FSNamesystem=DEBUG
 log4j.logger.org.apache.hadoop.hbase=INFO
+log4j.logger.org.apache.hadoop.hbase.META=INFO
 # Make these two classes INFO-level. Make them DEBUG to see more zk debug.
 log4j.logger.org.apache.hadoop.hbase.zookeeper.ZKUtil=INFO
 log4j.logger.org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher=INFO
 #log4j.logger.org.apache.hadoop.dfs=DEBUG
 # Set this class to log INFO only otherwise its OTT
 # Enable this to get detailed connection error/retry logging.
-# log4j.logger.org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation=TRACE
+# log4j.logger.org.apache.hadoop.hbase.client.ConnectionImplementation=TRACE
 
 
 # Uncomment this line to enable tracing on _every_ RPC call (this can be a lot of output)
@@ -90,5 +91,4 @@ log4j.logger.org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher=INFO
 
 # Uncomment the below if you want to remove logging of client region caching'
 # and scan of hbase:meta messages
-# log4j.logger.org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation=INFO
+# log4j.logger.org.apache.hadoop.hbase.client.ConnectionImplementation=INFO
-# log4j.logger.org.apache.hadoop.hbase.client.MetaScanner=INFO

dev-support/check_compatibility.sh

@@ -65,6 +65,7 @@ a branch (e.g. 0.98), or a particular commit hash. If ref2 is omitted, master
 will be used.
 
 Options:
+  -a, --all                     Do not filter by interface annotations.
   -b, --binary-only             Only run the check for binary compatibility.
   -f, --force-download          Download dependencies (i.e. Java ACC), even if they are
                                 already present.
@@ -88,8 +89,8 @@ __EOF
 GETOPT=${GETOPT:-/usr/bin/env getopt}
 
 # Parse command line arguments and check for proper syntax.
-if ! ARG_LIST=$(${GETOPT} -q -o bfhno:qr:s \
+if ! ARG_LIST=$(${GETOPT} -q -o abfhno:qr:s \
-    -l binary-only,force-download,help,no-checkout,options:,quick,repo:,source-only \
+    -l all,binary-only,force-download,help,no-checkout,options:,quick,repo:,source-only \
     -- "${@}"); then
   usage >&2
   exit 1
@@ -98,6 +99,9 @@ eval set -- "${ARG_LIST[@]}"
 
 while ((${#})); do
   case "${1}" in
+    -a | --all            )
+      ALL=true
+      shift 1 ;;
     -b | --binary-only    )
       JAVA_ACC_COMMAND+=(-binary)
       shift 1 ;;
@@ -244,10 +248,12 @@ fi
 
 # Generate annotation list dynamically; this way, there's no chance the file
 # gets stale and you have better visiblity into what classes are actually analyzed.
+declare -a ANNOTATION_LIST
 ANNOTATION_LIST+=(InterfaceAudience.Public)
+ANNOTATION_LIST+=(InterfaceAudience.LimitedPrivate)
 if ! [ -f ${SCRIPT_DIRECTORY}/target/compatibility/annotations ]; then
   cat > ${SCRIPT_DIRECTORY}/target/compatibility/annotations << __EOF
-$(tr " " "\n" <<< "${ANNOTATION_LIST}")
+$(tr " " "\n" <<< "${ANNOTATION_LIST[@]}")
 __EOF
 fi
 
@@ -257,7 +263,9 @@ JAVA_ACC_COMMAND+=(-v1 ${COMMIT[1]} -v2 ${COMMIT[2]})
 JAVA_ACC_COMMAND+=(-d1 ${JARS[1]} -d2 ${JARS[2]})
 JAVA_ACC_COMMAND+=(-report-path \
     ${SCRIPT_DIRECTORY}/target/compatibility/report/${COMMIT[1]}_${COMMIT[2]}_compat_report.html)
-JAVA_ACC_COMMAND+=(-annotations-list ${SCRIPT_DIRECTORY}/target/compatibility/annotations)
+if [ "${ALL}" != "true" ] ; then
+  JAVA_ACC_COMMAND+=(-annotations-list ${SCRIPT_DIRECTORY}/target/compatibility/annotations)
+fi
 
 # Delete any existing report folder under /dev-support/target/compatibility.
 rm -rf ${SCRIPT_DIRECTORY}/target/compatibility/report

dev-support/jenkinsEnv.sh

@@ -25,7 +25,7 @@ export CLOVER_HOME=/home/jenkins/tools/clover/latest
 export MAVEN_HOME=/home/jenkins/tools/maven/latest
 
 export PATH=$PATH:$JAVA_HOME/bin:$ANT_HOME/bin:
-export MAVEN_OPTS="-Xmx3100M -XX:-UsePerfData"
+export MAVEN_OPTS="${MAVEN_OPTS:-"-Xmx3100M -XX:-UsePerfData -XX:MaxPermSize=256m"}"
 
 ulimit -n
 

dev-support/publish_hbase_website.sh

@@ -83,12 +83,12 @@ echo "Updating Git"
 git checkout master
 git pull
 
-# Generate the site to ~/git/hbase/target/stage
+# Generate the site to ~/git/hbase/target/site
 if [ $INTERACTIVE ]; then
     read -p "Build the site? (y/n)" yn
     case $yn in
         [Yy]* ) 
-    			mvn clean package javadoc:aggregate site site:stage -DskipTests
+    			mvn clean package javadoc:aggregate site post-site site:stage -DskipTests
           status=$?
           if [ $status -ne 0 ]; then
             echo "The website does not build. Aborting."
@@ -101,7 +101,7 @@ if [ $INTERACTIVE ]; then
     esac
 else
   echo "Building the site in auto mode."
-  mvn clean package javadoc:aggregate site site:stage -DskipTests
+  mvn clean package javadoc:aggregate site post-site site:stage -DskipTests
   status=$?
   if [ $status != 0 ]; then
     echo "The website does not build. Aborting."
@@ -151,7 +151,7 @@ fi
 
 # Delete known auto-generated  content from trunk
 echo "Deleting known auto-generated content from SVN"
-rm -rf apidocs devapidocs xref xref-test book book.html java.html
+rm -rf apidocs devapidocs xref xref-test book book.html java.html apache_hbase_reference_guide.pdf*
 
 # Copy generated site to svn -- cp takes different options on Darwin and GNU
 echo "Copying the generated site to SVN"
@@ -161,18 +161,20 @@ elif [ `uname` == "Linux" ]; then
   COPYOPTS='-au'
 fi
 
-cp $COPYOPTS $GIT_DIR/target/site/* .
+cp $COPYOPTS $GIT_DIR/target/staging/* .
 
 # Look for things we need to fix up in svn
 
 echo "Untracked files: svn add"
-svn status |grep '?' |sed -e "s/[[:space:]]//g"|cut -d '?' -f 2|while read i
+svn status |grep '?' |sed -e "s/[[:space:]]//g"|cut -d '?' -f 2|while read i; do
-  do svn add $i 
+  svn add $i
+  echo "Added $i"
 done
 
 echo "Locally deleted files: svn del"
-svn status |grep '!' |sed -e "s/[[:space:]]//g"|cut -d '!' -f 2|while read i
+svn status |grep '!' |sed -e "s/[[:space:]]//g"|cut -d '!' -f 2|while read i; do
-  do svn del $i 
+  svn del $i
+  echo "Deleted $i"
 done
 
 # Display the proposed changes. I filtered out 
@@ -196,12 +198,12 @@ SVN_NUM_DIFF=`expr $SVN_NEW_NUMFILES - $SVN_OLD_NUMFILES|sed 's/-//g'`
 # The whole site is only 500 MB so a difference of 10 MB is huge
 # In this case, we should abort because something is wrong
 # Leaving this commented out for now until we get some benchmarks
-#if [ $SVN_SIZE_DIFF > 10 -o $SVN_NUM_DIFF > 50 ]; then
+if [ $SVN_SIZE_DIFF > 10 -o $SVN_NUM_DIFF > 50 ]; then
-#  echo "This commit would cause the website to change sizes by \
+  echo "This commit would cause the website to change sizes by \
-#  $SVN_DIFF MB and $SVN_NUM_DIFF files. There is likely a problem. 
+  $SVN_DIFF MB and $SVN_NUM_DIFF files. There is likely a problem.
-#  Aborting."
+  Aborting."
-#  exit 1
+  exit 1
-#fi
+fi
 
 
 if [ $INTERACTIVE ]; then

dev-support/test-patch.properties

@@ -13,13 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-MAVEN_OPTS="-Xmx3100M"
+MAVEN_OPTS="${MAVEN_OPTS:-"-Xmx3100M"}"
 
 # The number of acceptable warning for *all* modules
 # Please update the per-module test-patch.properties if you update this file.
 
 OK_RELEASEAUDIT_WARNINGS=0
-OK_FINDBUGS_WARNINGS=95
 # Allow two warnings.  Javadoc complains about sun.misc.Unsafe use.  See HBASE-7457
 OK_JAVADOC_WARNINGS=2
 
@@ -27,4 +26,8 @@ MAX_LINE_LENGTH=100
 
 # All supported branches for testing with precommit build
 # branch-1.x should apprear before branch-1 since the latter is a prefix
-BRANCH_NAMES="0.94 0.98 branch-1.0 branch-1 master"
+BRANCH_NAMES="0.94 0.98 branch-1.0 branch-1 master hbase-12439 hbase-11339"
+
+# All supported Hadoop versions that we want to test the compilation with
+HADOOP2_VERSIONS="2.4.1 2.5.2 2.6.0"
+HADOOP3_VERSIONS="3.0.0-SNAPSHOT"

dev-support/test-patch.sh

@@ -210,7 +210,7 @@ checkout () {
 findBranchNameFromPatchName() {
   local patchName=$1
   for LOCAL_BRANCH_NAME in $BRANCH_NAMES; do
-    if [[ $patchName =~ .*$LOCAL_BRANCH_NAME.* ]]; then
+    if [[ $patchName =~ /jira/secure/attachment/[0-9]*/.*$LOCAL_BRANCH_NAME ]]; then
       BRANCH_NAME=$LOCAL_BRANCH_NAME
       break
     fi
@@ -230,14 +230,42 @@ checkoutBranch() {
   echo ""
   if [[ $JENKINS == "true" ]] ; then
     if [[ "$BRANCH_NAME" != "master" ]]; then
-      echo "${GIT} checkout ${BRANCH_NAME}"
+      echo "origin/${BRANCH_NAME} HEAD is commit `${GIT} rev-list origin/${BRANCH_NAME} -1`"
-      ${GIT} checkout ${BRANCH_NAME}
+      echo "${GIT} checkout -f  `${GIT} rev-list origin/${BRANCH_NAME} -1`"
+      ${GIT} checkout -f  `${GIT} rev-list origin/${BRANCH_NAME} -1`
       echo "${GIT} status"
       ${GIT} status
     fi
   fi
 }
 
+###############################################################################
+###  Collect findbugs reports
+collectFindbugsReports() {
+  name=$1
+  basedir=$2
+  patch_dir=$3
+  for file in $(find $basedir -name findbugsXml.xml)
+  do
+    relative_file=${file#$basedir/} # strip leading $basedir prefix
+    if [ ! $relative_file == "target/findbugsXml.xml" ]; then
+      module_suffix=${relative_file%/target/findbugsXml.xml} # strip trailing path
+      module_suffix=`basename ${module_suffix}`
+    fi
+
+    cp $file $patch_dir/${name}FindbugsWarnings${module_suffix}.xml
+    $FINDBUGS_HOME/bin/setBugDatabaseInfo -name $name \
+      $patch_dir/${name}FindbugsWarnings${module_suffix}.xml \
+      $patch_dir/${name}FindbugsWarnings${module_suffix}.xml
+  done
+  xml_file=$patch_dir/${name}FindbugsWarnings.xml
+  html_file=$patch_dir/${name}FindbugsWarnings.html
+  $FINDBUGS_HOME/bin/unionBugs -withMessages \
+	 -output $xml_file $patch_dir/${name}FindbugsWarnings*.xml
+  $FINDBUGS_HOME/bin/convertXmlToText -html $xml_file $html_file
+  file $xml_file $html_file
+}
+
 ###############################################################################
 setup () {
   ### Download latest patch file (ignoring .htm and .html) when run from patch process
@@ -280,9 +308,8 @@ setup () {
     fi
   fi
   ### exit if warnings are NOT defined in the properties file
-  if [ -z "$OK_FINDBUGS_WARNINGS" ] || [[ -z "$OK_JAVADOC_WARNINGS" ]] || [[ -z $OK_RELEASEAUDIT_WARNINGS ]] ; then
+  if [[ -z "$OK_JAVADOC_WARNINGS" ]] || [[ -z $OK_RELEASEAUDIT_WARNINGS ]] ; then
     echo "Please define the following properties in test-patch.properties file"
-	 echo  "OK_FINDBUGS_WARNINGS"
 	 echo  "OK_RELEASEAUDIT_WARNINGS"
 	 echo  "OK_JAVADOC_WARNINGS"
     cleanupAndExit 1
@@ -296,10 +323,12 @@ setup () {
   echo "======================================================================"
   echo ""
   echo ""
-  echo "$MVN clean package checkstyle:checkstyle-aggregate -DskipTests -D${PROJECT_NAME}PatchProcess > $PATCH_DIR/trunkJavacWarnings.txt 2>&1"
+  echo "$MVN clean package checkstyle:checkstyle-aggregate findbugs:findbugs -DskipTests \
+ -D${PROJECT_NAME}PatchProcess > $PATCH_DIR/trunkJavacWarnings.txt 2>&1"
   export MAVEN_OPTS="${MAVEN_OPTS}"
   # build core and tests
-  $MVN clean package checkstyle:checkstyle-aggregate -DskipTests -D${PROJECT_NAME}PatchProcess > $PATCH_DIR/trunkJavacWarnings.txt 2>&1
+  $MVN clean package checkstyle:checkstyle-aggregate findbugs:findbugs -DskipTests \
+	 -D${PROJECT_NAME}PatchProcess > $PATCH_DIR/trunkJavacWarnings.txt 2>&1
   if [[ $? != 0 ]] ; then
     ERR=`$GREP -A 5 'Compilation failure' $PATCH_DIR/trunkJavacWarnings.txt`
     echo "Trunk compilation is broken?
@@ -307,6 +336,7 @@ setup () {
     cleanupAndExit 1
   fi
   mv target/checkstyle-result.xml $PATCH_DIR/trunkCheckstyle.xml
+  collectFindbugsReports trunk $BASEDIR $PATCH_DIR
 }
 
 ###############################################################################
@@ -360,6 +390,16 @@ checkTests () {
         return 0
       fi
     fi
+    srcReferences=`${GREP} "diff --git" "${PATCH_DIR}/patch" | ${GREP} "src/main" | \
+        ${GREP} -v "src/main/asciidoc" | ${GREP} -v "src/main/site" -c`
+    if [[ $srcReferences == 0 ]] ; then
+      echo "The patch doesn't appear to alter any code that requires tests."
+      JIRA_COMMENT="$JIRA_COMMENT
+
+    {color:green}+0 tests included{color}.  The patch appears to be a documentation, build,
+                        or dev-support patch that doesn't require tests."
+      return 0
+    fi
     JIRA_COMMENT="$JIRA_COMMENT
 
     {color:red}-1 tests included{color}.  The patch doesn't appear to include any new or modified tests.
@@ -377,17 +417,21 @@ checkTests () {
 ### Check there are no compilation errors, passing a file to be parsed.
 checkCompilationErrors() {
   local file=$1
+  hadoopVersion=""
+  if [ "$#" -ne 1 ]; then
+    hadoopVersion="with Hadoop version $2"
+  fi
   COMPILATION_ERROR=false
   eval $(awk '/ERROR/ {print "COMPILATION_ERROR=true"}' $file)
   if $COMPILATION_ERROR ; then
     ERRORS=$($AWK '/ERROR/ { print $0 }' $file)
     echo "======================================================================"
-    echo "There are compilation errors."
+    echo "There are compilation errors $hadoopVersion."
     echo "======================================================================"
     echo "$ERRORS"
     JIRA_COMMENT="$JIRA_COMMENT
 
-    {color:red}-1 javac{color}.  The patch appears to cause mvn compile goal to fail.
+    {color:red}-1 javac{color}.  The patch appears to cause mvn compile goal to fail $hadoopVersion.
 
     Compilation errors resume:
     $ERRORS
@@ -468,6 +512,29 @@ checkAntiPatterns () {
   return 0
 }
 
+###############################################################################
+### Check that there are no incorrect annotations
+checkInterfaceAudience () {
+  echo ""
+  echo ""
+  echo "======================================================================"
+  echo "======================================================================"
+  echo "    Checking against hadoop InterfaceAudience."
+  echo "======================================================================"
+  echo "======================================================================"
+  echo ""
+  echo ""
+  warnings=`$GREP 'import org.apache.hadoop.classification' $PATCH_DIR/patch`
+  if [[ $warnings != "" ]]; then
+    JIRA_COMMENT="$JIRA_COMMENT
+
+		    {color:red}-1 InterfaceAudience{color}.  The patch appears to contain InterfaceAudience from hadoop rather than hbase:
+             $warnings."
+	  return 1
+  fi
+  return 0
+}
+
 ###############################################################################
 ### Check there are no javadoc warnings
 checkJavadocWarnings () {
@@ -504,6 +571,31 @@ $JIRA_COMMENT_FOOTER"
   return 0
 }
 
+checkBuildWithHadoopVersions() {
+  echo ""
+  echo ""
+  echo "======================================================================"
+  echo "======================================================================"
+  echo "    Building with all supported Hadoop versions ."
+  echo "======================================================================"
+  echo "======================================================================"
+  echo ""
+  echo ""
+  export MAVEN_OPTS="${MAVEN_OPTS}"
+  for HADOOP2_VERSION in $HADOOP2_VERSIONS ; do
+	echo "$MVN clean install -DskipTests -D${PROJECT_NAME}PatchProcess -Dhadoop-two.version=$HADOOP2_VERSION > $PATCH_DIR/patchJavacWithHadoop-$HADOOP2_VERSION.txt 2>&1"
+    $MVN clean install -DskipTests -D${PROJECT_NAME}PatchProcess -Dhadoop-two.version=$HADOOP2_VERSION > $PATCH_DIR/patchJavacWithHadoop-$HADOOP2_VERSION.txt 2>&1
+    checkCompilationErrors $PATCH_DIR/patchJavacWithHadoop-$HADOOP2_VERSION.txt $HADOOP2_VERSION
+  done
+
+  # TODO: add Hadoop3 versions and compilation here when we get the hadoop.profile=3.0 working
+
+  JIRA_COMMENT="$JIRA_COMMENT
+
+    {color:green}+1 hadoop versions{color}. The patch compiles with all supported hadoop versions ($HADOOP2_VERSIONS)"
+  return 0
+}
+
 ###############################################################################
 ### Check there are no changes in the number of Javac warnings
 checkJavacWarnings () {
@@ -596,7 +688,7 @@ checkProtocErrors () {
   checkProtocCompilationErrors $PATCH_DIR/patchProtocErrors.txt
   JIRA_COMMENT="$JIRA_COMMENT
 
-    {color:green}+1 javac{color}.  The applied patch does not increase the total number of javac compiler warnings."
+    {color:green}+1 protoc{color}.  The applied patch does not increase the total number of protoc compiler warnings."
   return 0
 }
 
@@ -665,41 +757,36 @@ checkFindbugsWarnings () {
     {color:red}-1 findbugs{color}.  The patch appears to cause Findbugs (version ${findbugs_version}) to fail."
     return 1
   fi
-    
-  findbugsWarnings=0
-  for file in $(find $BASEDIR -name findbugsXml.xml)
-  do
-    relative_file=${file#$BASEDIR/} # strip leading $BASEDIR prefix
-    if [ ! $relative_file == "target/findbugsXml.xml" ]; then
-      module_suffix=${relative_file%/target/findbugsXml.xml} # strip trailing path
-      module_suffix=`basename ${module_suffix}`
-    fi
-    
-    cp $file $PATCH_DIR/patchFindbugsWarnings${module_suffix}.xml
-    $FINDBUGS_HOME/bin/setBugDatabaseInfo -timestamp "01/01/2000" \
-      $PATCH_DIR/patchFindbugsWarnings${module_suffix}.xml \
-      $PATCH_DIR/patchFindbugsWarnings${module_suffix}.xml
-    newFindbugsWarnings=`$FINDBUGS_HOME/bin/filterBugs -first "01/01/2000" $PATCH_DIR/patchFindbugsWarnings${module_suffix}.xml \
-      $PATCH_DIR/newPatchFindbugsWarnings${module_suffix}.xml | $AWK '{print $1}'`
-    echo "Found $newFindbugsWarnings Findbugs warnings ($file)"
-    findbugsWarnings=$((findbugsWarnings+newFindbugsWarnings))
-    echo "$FINDBUGS_HOME/bin/convertXmlToText -html  $PATCH_DIR/newPatchFindbugsWarnings${module_suffix}.xml $PATCH_DIR/newPatchFindbugsWarnings${module_suffix}.html"
-    $FINDBUGS_HOME/bin/convertXmlToText -html  $PATCH_DIR/newPatchFindbugsWarnings${module_suffix}.xml $PATCH_DIR/newPatchFindbugsWarnings${module_suffix}.html
-    file $PATCH_DIR/newPatchFindbugsWarnings${module_suffix}.xml $PATCH_DIR/newPatchFindbugsWarnings${module_suffix}.html
-    JIRA_COMMENT_FOOTER="Findbugs warnings: $BUILD_URL/artifact/patchprocess/newPatchFindbugsWarnings${module_suffix}.html
-$JIRA_COMMENT_FOOTER"
-  done
 
-  ### if current warnings greater than OK_FINDBUGS_WARNINGS
+  collectFindbugsReports patch $BASEDIR $PATCH_DIR 
-  if [[ $findbugsWarnings -gt $OK_FINDBUGS_WARNINGS ]] ; then
+  #this files are generated by collectFindbugsReports() named with its first argument
+  patch_xml=$PATCH_DIR/patchFindbugsWarnings.xml
+  trunk_xml=$PATCH_DIR/trunkFindbugsWarnings.xml
+  # combine them to one database
+  combined_xml=$PATCH_DIR/combinedFindbugsWarnings.xml
+  new_xml=$PATCH_DIR/newFindbugsWarnings.xml
+  new_html=$PATCH_DIR/newFindbugsWarnings.html
+  $FINDBUGS_HOME/bin/computeBugHistory -useAnalysisTimes -withMessages \
+	-output $combined_xml $trunk_xml $patch_xml
+  findbugsWarnings=$($FINDBUGS_HOME/bin/filterBugs -first patch $combined_xml $new_xml)
+  findbugsFixedWarnings=$($FINDBUGS_HOME/bin/filterBugs -fixed patch $combined_xml $new_xml)
+  $FINDBUGS_HOME/bin/convertXmlToText -html  $new_xml $new_html
+  file $new_xml $new_html
+  JIRA_COMMENT_FOOTER="Release Findbugs (version ${findbugs_version}) \
+	warnings: $BUILD_URL/artifact/patchprocess/newFindbugsWarnings.html
+$JIRA_COMMENT_FOOTER"
+  ### if current warnings greater than 0, fail
+  if [[ $findbugsWarnings -gt 0 ]] ; then
     JIRA_COMMENT="$JIRA_COMMENT
 
-    {color:red}-1 findbugs{color}.  The patch appears to introduce `expr $(($findbugsWarnings-$OK_FINDBUGS_WARNINGS))` new Findbugs (version ${findbugs_version}) warnings."
+    {color:red}-1 findbugs{color}.  The patch appears to introduce $findbugsWarnings \
+ new Findbugs (version ${findbugs_version}) warnings."
     return 1
   fi
   JIRA_COMMENT="$JIRA_COMMENT
 
-    {color:green}+1 findbugs{color}.  The patch does not introduce any new Findbugs (version ${findbugs_version}) warnings."
+    {color:green}+1 findbugs{color}.  The patch does not introduce any \
+ new Findbugs (version ${findbugs_version}) warnings."
   return 0
 }
 
@@ -956,6 +1043,8 @@ fi
 
 checkAntiPatterns
 (( RESULT = RESULT + $? ))
+checkBuildWithHadoopVersions
+(( RESULT = RESULT + $? ))
 checkJavacWarnings
 (( RESULT = RESULT + $? ))
 checkProtocErrors
@@ -964,6 +1053,8 @@ checkJavadocWarnings
 (( RESULT = RESULT + $? ))
 checkCheckstyleErrors
 (( RESULT = RESULT + $? ))
+checkInterfaceAudience
+(( RESULT = RESULT + $? ))
 checkFindbugsWarnings
 (( RESULT = RESULT + $? ))
 checkReleaseAuditWarnings

hbase-client/pom.xml

@@ -34,25 +34,6 @@
 
   <build>
     <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <executions>
-          <execution>
-            <id>default-compile</id>
-            <configuration>
-              <compilerId>${java.default.compiler}</compilerId>
-              <forceJavacCompilerUse>true</forceJavacCompilerUse>
-            </configuration>
-          </execution>
-          <execution>
-            <id>default-testCompile</id>
-            <configuration>
-              <compilerId>${java.default.compiler}</compilerId>
-              <forceJavacCompilerUse>true</forceJavacCompilerUse>
-            </configuration>
-          </execution>
-       </executions>
-      </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-site-plugin</artifactId>
@@ -91,6 +72,36 @@
         <artifactId>maven-source-plugin</artifactId>
       </plugin>
     </plugins>
+    <pluginManagement>
+      <plugins>
+        <!--This plugin's configuration is used to store Eclipse m2e settings
+             only. It has no influence on the Maven build itself.-->
+        <plugin>
+          <groupId>org.eclipse.m2e</groupId>
+          <artifactId>lifecycle-mapping</artifactId>
+          <version>1.0.0</version>
+          <configuration>
+            <lifecycleMappingMetadata>
+              <pluginExecutions>
+                <pluginExecution>
+                  <pluginExecutionFilter>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <versionRange>[3.2,)</versionRange>
+                    <goals>
+                      <goal>compile</goal>
+                    </goals>
+                  </pluginExecutionFilter>
+                  <action>
+                    <ignore></ignore>
+                  </action>
+                </pluginExecution>
+              </pluginExecutions>
+            </lifecycleMappingMetadata>
+          </configuration>
+        </plugin>
+      </plugins>
+    </pluginManagement>
   </build>
 
   <dependencies>

hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterStatus.java

@@ -118,6 +118,9 @@ public class ClusterStatus extends VersionedWritable {
    * @return the names of region servers on the dead list
    */
   public Collection<ServerName> getDeadServerNames() {
+    if (deadServers == null) {
+      return Collections.<ServerName>emptyList();
+    }
     return Collections.unmodifiableCollection(deadServers);
   }
 
@@ -125,14 +128,14 @@ public class ClusterStatus extends VersionedWritable {
    * @return the number of region servers in the cluster
    */
   public int getServersSize() {
-    return liveServers.size();
+    return liveServers != null ? liveServers.size() : 0;
   }
 
   /**
    * @return the number of dead region servers in the cluster
    */
   public int getDeadServers() {
-    return deadServers.size();
+    return deadServers != null ? deadServers.size() : 0;
   }
 
   /**
@@ -148,8 +151,10 @@ public class ClusterStatus extends VersionedWritable {
    */
   public int getRegionsCount() {
     int count = 0;
-    for (Map.Entry<ServerName, ServerLoad> e: this.liveServers.entrySet()) {
+    if (liveServers != null && !liveServers.isEmpty()) {
-      count += e.getValue().getNumberOfRegions();
+      for (Map.Entry<ServerName, ServerLoad> e: this.liveServers.entrySet()) {
+        count += e.getValue().getNumberOfRegions();
+      }
     }
     return count;
   }
@@ -159,8 +164,10 @@ public class ClusterStatus extends VersionedWritable {
    */
   public int getRequestsCount() {
     int count = 0;
-    for (Map.Entry<ServerName, ServerLoad> e: this.liveServers.entrySet()) {
+    if (liveServers != null && !liveServers.isEmpty()) {
-      count += e.getValue().getNumberOfRequests();
+      for (Map.Entry<ServerName, ServerLoad> e: this.liveServers.entrySet()) {
+        count += e.getValue().getNumberOfRequests();
+      }
     }
     return count;
   }
@@ -222,6 +229,9 @@ public class ClusterStatus extends VersionedWritable {
   }
 
   public Collection<ServerName> getServers() {
+    if (liveServers == null) {
+      return Collections.<ServerName>emptyList();
+    }
     return Collections.unmodifiableCollection(this.liveServers.keySet());
   }
 
@@ -237,13 +247,16 @@ public class ClusterStatus extends VersionedWritable {
    * @return the number of backup masters in the cluster
    */
   public int getBackupMastersSize() {
-    return this.backupMasters.size();
+    return backupMasters != null ? backupMasters.size() : 0;
   }
 
   /**
    * @return the names of backup masters
    */
   public Collection<ServerName> getBackupMasters() {
+    if (backupMasters == null) {
+      return Collections.<ServerName>emptyList();
+    }
     return Collections.unmodifiableCollection(this.backupMasters);
   }
 
@@ -252,7 +265,7 @@ public class ClusterStatus extends VersionedWritable {
    * @return Server's load or null if not found.
    */
   public ServerLoad getLoad(final ServerName sn) {
-    return this.liveServers.get(sn);
+    return liveServers != null ? liveServers.get(sn) : null;
   }
 
   @InterfaceAudience.Private
@@ -303,27 +316,41 @@ public class ClusterStatus extends VersionedWritable {
   public String toString() {
     StringBuilder sb = new StringBuilder(1024);
     sb.append("Master: " + master);
-    sb.append("\nNumber of backup masters: " + backupMasters.size());
+
-    for (ServerName serverName: backupMasters) {
+    int backupMastersSize = getBackupMastersSize();
-      sb.append("\n  " + serverName);
+    sb.append("\nNumber of backup masters: " + backupMastersSize);
+    if (backupMastersSize > 0) {
+      for (ServerName serverName: backupMasters) {
+        sb.append("\n  " + serverName);
+      }
     }
 
-    sb.append("\nNumber of live region servers: " + liveServers.size());
+    int serversSize = getServersSize();
-    for (ServerName serverName: liveServers.keySet()) {
+    sb.append("\nNumber of live region servers: " + serversSize);
-      sb.append("\n  " + serverName.getServerName());
+    if (serversSize > 0) {
+      for (ServerName serverName: liveServers.keySet()) {
+        sb.append("\n  " + serverName.getServerName());
+      }
     }
 
-    sb.append("\nNumber of dead region servers: " + deadServers.size());
+    int deadServerSize = getDeadServers();
-    for (ServerName serverName: deadServers) {
+    sb.append("\nNumber of dead region servers: " + deadServerSize);
-      sb.append("\n  " + serverName);
+    if (deadServerSize > 0) {
+      for (ServerName serverName: deadServers) {
+        sb.append("\n  " + serverName);
+      }
     }
 
     sb.append("\nAverage load: " + getAverageLoad());
     sb.append("\nNumber of requests: " + getRequestsCount());
     sb.append("\nNumber of regions: " + getRegionsCount());
-    sb.append("\nNumber of regions in transition: " + intransition.size());
+
-    for (RegionState state: intransition.values()) {
+    int ritSize = (intransition != null) ? intransition.size() : 0;
-      sb.append("\n  " + state.toDescriptiveString());
+    sb.append("\nNumber of regions in transition: " + ritSize);
+    if (ritSize > 0) {
+      for (RegionState state: intransition.values()) {
+        sb.append("\n  " + state.toDescriptiveString());
+      }
     }
     return sb.toString();
   }

hbase-client/src/main/java/org/apache/hadoop/hbase/CoprocessorEnvironment.java

@@ -20,7 +20,7 @@ import java.util.concurrent.ExecutorService;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
-import org.apache.hadoop.hbase.client.HTableInterface;
+import org.apache.hadoop.hbase.client.Table;
 
 /**
  * Coprocessor environment state.
@@ -50,14 +50,14 @@ public interface CoprocessorEnvironment {
    * @return an interface for accessing the given table
    * @throws IOException
    */
-  HTableInterface getTable(TableName tableName) throws IOException;
+  Table getTable(TableName tableName) throws IOException;
 
   /**
    * @return an interface for accessing the given table using the passed executor to run batch
    *         operations
    * @throws IOException
    */
-  HTableInterface getTable(TableName tableName, ExecutorService service) throws IOException;
+  Table getTable(TableName tableName, ExecutorService service) throws IOException;
 
   /**
    * @return the classloader for the loaded coprocessor instance

hbase-client/src/main/java/org/apache/hadoop/hbase/HColumnDescriptor.java

@@ -742,7 +742,7 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
     String compressTagsStr = getValue(COMPRESS_TAGS);
     boolean compressTags = DEFAULT_COMPRESS_TAGS;
     if (compressTagsStr != null) {
-      compressTags = Boolean.valueOf(compressTagsStr);
+      compressTags = Boolean.parseBoolean(compressTagsStr);
     }
     return compressTags;
   }
@@ -755,7 +755,7 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
     String compressTagsStr = getValue(COMPRESS_TAGS);
     boolean compressTags = DEFAULT_COMPRESS_TAGS;
     if (compressTagsStr != null) {
-      compressTags = Boolean.valueOf(compressTagsStr);
+      compressTags = Boolean.parseBoolean(compressTagsStr);
     }
     return compressTags;
   }
@@ -786,8 +786,9 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
    */
   public boolean isInMemory() {
     String value = getValue(HConstants.IN_MEMORY);
-    if (value != null)
+    if (value != null) {
-      return Boolean.valueOf(value).booleanValue();
+      return Boolean.parseBoolean(value);
+    }
     return DEFAULT_IN_MEMORY;
   }
 
@@ -835,7 +836,7 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
    */
   public int getTimeToLive() {
     String value = getValue(TTL);
-    return (value != null)? Integer.valueOf(value).intValue(): DEFAULT_TTL;
+    return (value != null)? Integer.parseInt(value) : DEFAULT_TTL;
   }
 
   /**
@@ -851,7 +852,7 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
    */
   public int getMinVersions() {
     String value = getValue(MIN_VERSIONS);
-    return (value != null)? Integer.valueOf(value).intValue(): 0;
+    return (value != null)? Integer.parseInt(value) : 0;
   }
 
   /**
@@ -869,8 +870,9 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
    */
   public boolean isBlockCacheEnabled() {
     String value = getValue(BLOCKCACHE);
-    if (value != null)
+    if (value != null) {
-      return Boolean.valueOf(value).booleanValue();
+      return Boolean.parseBoolean(value);
+    }
     return DEFAULT_BLOCKCACHE;
   }
 
@@ -908,7 +910,7 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
   public int getScope() {
     byte[] value = getValue(REPLICATION_SCOPE_BYTES);
     if (value != null) {
-      return Integer.valueOf(Bytes.toString(value));
+      return Integer.parseInt(Bytes.toString(value));
     }
     return DEFAULT_REPLICATION_SCOPE;
   }
@@ -974,7 +976,9 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
 
   private boolean setAndGetBoolean(final String key, final boolean defaultSetting) {
     String value = getValue(key);
-    if (value != null) return Boolean.valueOf(value).booleanValue();
+    if (value != null) {
+      return Boolean.parseBoolean(value);
+    }
     return defaultSetting;
   }
 
@@ -1213,7 +1217,7 @@ public class HColumnDescriptor implements Comparable<HColumnDescriptor> {
   @Override
   public int hashCode() {
     int result = Bytes.hashCode(this.name);
-    result ^= Byte.valueOf(COLUMN_DESCRIPTOR_VERSION).hashCode();
+    result ^= (int) COLUMN_DESCRIPTOR_VERSION;
     result ^= values.hashCode();
     result ^= configuration.hashCode();
     return result;

hbase-client/src/main/java/org/apache/hadoop/hbase/HTableDescriptor.java

@@ -38,6 +38,7 @@ import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.client.Durability;
+import org.apache.hadoop.hbase.client.RegionReplicaUtil;
 import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.BytesBytesPair;
@@ -176,6 +177,14 @@ public class HTableDescriptor implements Comparable<HTableDescriptor> {
   private static final Bytes REGION_REPLICATION_KEY =
       new Bytes(Bytes.toBytes(REGION_REPLICATION));
 
+  /**
+   * <em>INTERNAL</em> flag to indicate whether or not the memstore should be replicated
+   * for read-replicas (CONSISTENCY => TIMELINE).
+   */
+  public static final String REGION_MEMSTORE_REPLICATION = "REGION_MEMSTORE_REPLICATION";
+  private static final Bytes REGION_MEMSTORE_REPLICATION_KEY =
+      new Bytes(Bytes.toBytes(REGION_MEMSTORE_REPLICATION));
+
   /** Default durability for HTD is USE_DEFAULT, which defaults to HBase-global default value */
   private static final Durability DEFAULT_DURABLITY = Durability.USE_DEFAULT;
 
@@ -210,6 +219,8 @@ public class HTableDescriptor implements Comparable<HTableDescriptor> {
 
   public static final int DEFAULT_REGION_REPLICATION = 1;
 
+  public static final boolean DEFAULT_REGION_MEMSTORE_REPLICATION = true;
+
   private final static Map<String, String> DEFAULT_VALUES
     = new HashMap<String, String>();
   private final static Set<Bytes> RESERVED_KEYWORDS
@@ -1073,6 +1084,31 @@ public class HTableDescriptor implements Comparable<HTableDescriptor> {
     return this;
   }
 
+  /**
+   * @return true if the read-replicas memstore replication is enabled.
+   */
+  public boolean hasRegionMemstoreReplication() {
+    return isSomething(REGION_MEMSTORE_REPLICATION_KEY, DEFAULT_REGION_MEMSTORE_REPLICATION);
+  }
+
+  /**
+   * Enable or Disable the memstore replication from the primary region to the replicas.
+   * The replication will be used only for meta operations (e.g. flush, compaction, ...)
+   *
+   * @param memstoreReplication true if the new data written to the primary region
+   *                                 should be replicated.
+   *                            false if the secondaries can tollerate to have new
+   *                                  data only when the primary flushes the memstore.
+   */
+  public HTableDescriptor setRegionMemstoreReplication(boolean memstoreReplication) {
+    setValue(REGION_MEMSTORE_REPLICATION_KEY, memstoreReplication ? TRUE : FALSE);
+    // If the memstore replication is setup, we do not have to wait for observing a flush event
+    // from primary before starting to serve reads, because gaps from replication is not applicable
+    setConfiguration(RegionReplicaUtil.REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY,
+      Boolean.toString(memstoreReplication));
+    return this;
+  }
+
   /**
    * Returns all the column family names of the current table. The map of
    * HTableDescriptor contains mapping of family name to HColumnDescriptors.

hbase-client/src/main/java/org/apache/hadoop/hbase/MetaTableAccessor.java

@@ -17,7 +17,9 @@
  */
 package org.apache.hadoop.hbase;
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.io.Closeable;
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.util.ArrayList;
@@ -38,12 +40,11 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
-import org.apache.hadoop.hbase.client.ClusterConnection;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
+import org.apache.hadoop.hbase.client.Consistency;
 import org.apache.hadoop.hbase.client.Delete;
 import org.apache.hadoop.hbase.client.Get;
-import org.apache.hadoop.hbase.client.HTable;
 import org.apache.hadoop.hbase.client.Mutation;
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.client.RegionLocator;
@@ -60,6 +61,7 @@ import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
 import org.apache.hadoop.hbase.protobuf.generated.MultiRowMutationProtos;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+import org.apache.hadoop.hbase.util.ExceptionUtil;
 import org.apache.hadoop.hbase.util.Pair;
 import org.apache.hadoop.hbase.util.PairOfSameType;
 import org.apache.hadoop.hbase.util.Threads;
@@ -118,6 +120,7 @@ public class MetaTableAccessor {
    */
 
   private static final Log LOG = LogFactory.getLog(MetaTableAccessor.class);
+  private static final Log METALOG = LogFactory.getLog("org.apache.hadoop.hbase.META");
 
   static final byte [] META_REGION_PREFIX;
   static {
@@ -129,6 +132,37 @@ public class MetaTableAccessor {
       META_REGION_PREFIX, 0, len);
   }
 
+  /**
+   * Lists all of the table regions currently in META.
+   * Deprecated, keep there until some test use this.
+   * @param connection what we will use
+   * @param tableName table to list
+   * @return Map of all user-space regions to servers
+   * @throws java.io.IOException
+   * @deprecated use {@link #getTableRegionsAndLocations}, region can have multiple locations
+   */
+  @Deprecated
+  public static NavigableMap<HRegionInfo, ServerName> allTableRegions(
+      Connection connection, final TableName tableName) throws IOException {
+    final NavigableMap<HRegionInfo, ServerName> regions =
+      new TreeMap<HRegionInfo, ServerName>();
+    Visitor visitor = new TableVisitorBase(tableName) {
+      @Override
+      public boolean visitInternal(Result result) throws IOException {
+        RegionLocations locations = getRegionLocations(result);
+        if (locations == null) return true;
+        for (HRegionLocation loc : locations.getRegionLocations()) {
+          if (loc != null) {
+            HRegionInfo regionInfo = loc.getRegionInfo();
+            regions.put(regionInfo, loc.getServerName());
+          }
+        }
+        return true;
+      }
+    };
+    scanMetaForTableRegions(connection, visitor, tableName);
+    return regions;
+  }
 
   @InterfaceAudience.Private
   public enum QueryType {
@@ -167,7 +201,7 @@ public class MetaTableAccessor {
   public static void fullScanRegions(Connection connection,
       final Visitor visitor)
       throws IOException {
-    fullScan(connection, visitor, null, QueryType.REGION);
+    scanMeta(connection, null, null, QueryType.REGION, visitor);
   }
 
   /**
@@ -189,20 +223,7 @@ public class MetaTableAccessor {
   public static void fullScanTables(Connection connection,
       final Visitor visitor)
       throws IOException {
-    fullScan(connection, visitor, null, QueryType.TABLE);
+    scanMeta(connection, null, null, QueryType.TABLE, visitor);
-  }
-
-  /**
-   * Performs a full scan of <code>hbase:meta</code>.
-   * @param connection connection we're using
-   * @param visitor Visitor invoked against each row.
-   * @param type scanned part of meta
-   * @throws IOException
-   */
-  public static void fullScan(Connection connection,
-      final Visitor visitor, QueryType type)
-  throws IOException {
-    fullScan(connection, visitor, null, type);
   }
 
   /**
@@ -215,7 +236,7 @@ public class MetaTableAccessor {
   public static List<Result> fullScan(Connection connection, QueryType type)
     throws IOException {
     CollectAllVisitor v = new CollectAllVisitor();
-    fullScan(connection, v, null, type);
+    scanMeta(connection, null, null, type, v);
     return v.getResults();
   }
 
@@ -228,21 +249,10 @@ public class MetaTableAccessor {
   static Table getMetaHTable(final Connection connection)
   throws IOException {
     // We used to pass whole CatalogTracker in here, now we just pass in Connection
-    if (connection == null || connection.isClosed()) {
+    if (connection == null) {
       throw new NullPointerException("No connection");
-    }
+    } else if (connection.isClosed()) {
-    // If the passed in 'connection' is 'managed' -- i.e. every second test uses
+      throw new IOException("connection is closed");
-    // a Table or an HBaseAdmin with managed connections -- then doing
-    // connection.getTable will throw an exception saying you are NOT to use
-    // managed connections getting tables.  Leaving this as it is for now. Will
-    // revisit when inclined to change all tests.  User code probaby makes use of
-    // managed connections too so don't change it till post hbase 1.0.
-    //
-    // There should still be a way to use this method with an unmanaged connection.
-    if (connection instanceof ClusterConnection) {
-      if (((ClusterConnection) connection).isManaged()) {
-        return new HTable(TableName.META_TABLE_NAME, connection);
-      }
     }
     return connection.getTable(TableName.META_TABLE_NAME);
   }
@@ -385,6 +395,28 @@ public class MetaTableAccessor {
         || getTableState(connection, tableName) != null;
   }
 
+  /**
+   * Lists all of the regions currently in META.
+   *
+   * @param connection to connect with
+   * @param excludeOfflinedSplitParents False if we are to include offlined/splitparents regions,
+   *                                    true and we'll leave out offlined regions from returned list
+   * @return List of all user-space regions.
+   * @throws IOException
+   */
+  @VisibleForTesting
+  public static List<HRegionInfo> getAllRegions(Connection connection,
+      boolean excludeOfflinedSplitParents)
+      throws IOException {
+    List<Pair<HRegionInfo, ServerName>> result;
+
+    result = getTableRegionsAndLocations(connection, null,
+        excludeOfflinedSplitParents);
+
+    return getListOfHRegionInfos(result);
+
+  }
+
   /**
    * Gets all of the regions of the specified table. Do not use this method
    * to get meta table regions, use methods in MetaTableLocator instead.
@@ -441,15 +473,52 @@ public class MetaTableAccessor {
 
   /**
    * @param tableName table we're working with
-   * @return Place to start Scan in <code>hbase:meta</code> when passed a
+   * @return start row for scanning META according to query type
-   * <code>tableName</code>; returns &lt;tableName&rt; &lt;,&rt; &lt;,&rt;
    */
-  static byte [] getTableStartRowForMeta(TableName tableName) {
+  public static byte[] getTableStartRowForMeta(TableName tableName, QueryType type) {
-    byte [] startRow = new byte[tableName.getName().length + 2];
+    if (tableName == null) {
-    System.arraycopy(tableName.getName(), 0, startRow, 0, tableName.getName().length);
+      return null;
-    startRow[startRow.length - 2] = HConstants.DELIMITER;
+    }
-    startRow[startRow.length - 1] = HConstants.DELIMITER;
+    switch (type) {
-    return startRow;
+    case REGION:
+      byte[] startRow = new byte[tableName.getName().length + 2];
+      System.arraycopy(tableName.getName(), 0, startRow, 0, tableName.getName().length);
+      startRow[startRow.length - 2] = HConstants.DELIMITER;
+      startRow[startRow.length - 1] = HConstants.DELIMITER;
+      return startRow;
+    case ALL:
+    case TABLE:
+    default:
+      return tableName.getName();
+    }
+  }
+
+  /**
+   * @param tableName table we're working with
+   * @return stop row for scanning META according to query type
+   */
+  public static byte[] getTableStopRowForMeta(TableName tableName, QueryType type) {
+    if (tableName == null) {
+      return null;
+    }
+    final byte[] stopRow;
+    switch (type) {
+    case REGION:
+      stopRow = new byte[tableName.getName().length + 3];
+      System.arraycopy(tableName.getName(), 0, stopRow, 0, tableName.getName().length);
+      stopRow[stopRow.length - 3] = ' ';
+      stopRow[stopRow.length - 2] = HConstants.DELIMITER;
+      stopRow[stopRow.length - 1] = HConstants.DELIMITER;
+      break;
+    case ALL:
+    case TABLE:
+    default:
+      stopRow = new byte[tableName.getName().length + 1];
+      System.arraycopy(tableName.getName(), 0, stopRow, 0, tableName.getName().length);
+      stopRow[stopRow.length - 1] = ' ';
+      break;
+    }
+    return stopRow;
   }
 
   /**
@@ -461,18 +530,39 @@ public class MetaTableAccessor {
    * @param tableName bytes of table's name
    * @return configured Scan object
    */
-  public static Scan getScanForTableName(TableName tableName) {
+  @Deprecated
-    String strName = tableName.getNameAsString();
+  public static Scan getScanForTableName(Connection connection, TableName tableName) {
     // Start key is just the table name with delimiters
-    byte[] startKey = Bytes.toBytes(strName + ",,");
+    byte[] startKey = getTableStartRowForMeta(tableName, QueryType.REGION);
     // Stop key appends the smallest possible char to the table name
-    byte[] stopKey = Bytes.toBytes(strName + " ,,");
+    byte[] stopKey = getTableStopRowForMeta(tableName, QueryType.REGION);
 
-    Scan scan = new Scan(startKey);
+    Scan scan = getMetaScan(connection);
+    scan.setStartRow(startKey);
     scan.setStopRow(stopKey);
     return scan;
   }
 
+  private static Scan getMetaScan(Connection connection) {
+    return getMetaScan(connection, Integer.MAX_VALUE);
+  }
+
+  private static Scan getMetaScan(Connection connection, int rowUpperLimit) {
+    Scan scan = new Scan();
+    int scannerCaching = connection.getConfiguration()
+        .getInt(HConstants.HBASE_META_SCANNER_CACHING,
+            HConstants.DEFAULT_HBASE_META_SCANNER_CACHING);
+    if (connection.getConfiguration().getBoolean(HConstants.USE_META_REPLICAS,
+        HConstants.DEFAULT_USE_META_REPLICAS)) {
+      scan.setConsistency(Consistency.TIMELINE);
+    }
+    if (rowUpperLimit <= scannerCaching) {
+      scan.setSmall(true);
+    }
+    int rows = Math.min(rowUpperLimit, scannerCaching);
+    scan.setCaching(rows);
+    return scan;
+  }
   /**
    * Do not use this method to get meta table regions, use methods in MetaTableLocator instead.
    * @param connection connection we're using
@@ -489,15 +579,15 @@ public class MetaTableAccessor {
   /**
    * Do not use this method to get meta table regions, use methods in MetaTableLocator instead.
    * @param connection connection we're using
-   * @param tableName table to work with
+   * @param tableName table to work with, can be null for getting all regions
    * @param excludeOfflinedSplitParents don't return split parents
    * @return Return list of regioninfos and server addresses.
    * @throws IOException
    */
   public static List<Pair<HRegionInfo, ServerName>> getTableRegionsAndLocations(
-        Connection connection, final TableName tableName,
+      Connection connection, @Nullable final TableName tableName,
       final boolean excludeOfflinedSplitParents) throws IOException {
-    if (tableName.equals(TableName.META_TABLE_NAME)) {
+    if (tableName != null && tableName.equals(TableName.META_TABLE_NAME)) {
       throw new IOException("This method can't be used to locate meta regions;"
         + " use MetaTableLocator instead");
     }
@@ -514,7 +604,6 @@ public class MetaTableAccessor {
             return true;
           }
           HRegionInfo hri = current.getRegionLocation().getRegionInfo();
-          if (!isInsideTable(hri, tableName)) return false;
           if (excludeOfflinedSplitParents && hri.isSplitParent()) return true;
           // Else call super and add this Result to the collection.
           return super.visit(r);
@@ -533,7 +622,10 @@ public class MetaTableAccessor {
           }
         }
       };
-    fullScan(connection, visitor, getTableStartRowForMeta(tableName), QueryType.REGION);
+    scanMeta(connection,
+        getTableStartRowForMeta(tableName, QueryType.REGION),
+        getTableStopRowForMeta(tableName, QueryType.REGION),
+        QueryType.REGION, visitor);
     return visitor.getResults();
   }
 
@@ -565,7 +657,7 @@ public class MetaTableAccessor {
         }
       }
     };
-    fullScan(connection, v, QueryType.REGION);
+    scanMeta(connection, null, null, QueryType.REGION, v);
     return hris;
   }
 
@@ -591,62 +683,140 @@ public class MetaTableAccessor {
         return true;
       }
     };
-    fullScan(connection, v, QueryType.ALL);
+    scanMeta(connection, null, null, QueryType.ALL, v);
+  }
+
+  public static void scanMetaForTableRegions(Connection connection,
+      Visitor visitor, TableName tableName) throws IOException {
+    scanMeta(connection, tableName, QueryType.REGION, Integer.MAX_VALUE, visitor);
+  }
+
+  public static void scanMeta(Connection connection, TableName table,
+      QueryType type, int maxRows, final Visitor visitor) throws IOException {
+    scanMeta(connection, getTableStartRowForMeta(table, type), getTableStopRowForMeta(table, type),
+        type, maxRows, visitor);
+  }
+
+  public static void scanMeta(Connection connection,
+      @Nullable final byte[] startRow, @Nullable final byte[] stopRow,
+      QueryType type, final Visitor visitor) throws IOException {
+    scanMeta(connection, startRow, stopRow, type, Integer.MAX_VALUE, visitor);
   }
 
   /**
-   * Performs a full scan of a catalog table.
+   * Performs a scan of META table for given table starting from
+   * given row.
+   *
    * @param connection connection we're using
-   * @param visitor Visitor invoked against each row.
+   * @param visitor    visitor to call
-   * @param startrow Where to start the scan. Pass null if want to begin scan
+   * @param tableName  table withing we scan
-   * at first row.
+   * @param row        start scan from this row
-   * @param type scanned part of meta
+   * @param rowLimit   max number of rows to return
-   * <code>hbase:meta</code>, the default (pass false to scan hbase:meta)
    * @throws IOException
    */
-  public static void fullScan(Connection connection,
+  public static void scanMeta(Connection connection,
-      final Visitor visitor, @Nullable final byte[] startrow, QueryType type) throws IOException {
+      final Visitor visitor, final TableName tableName,
-    fullScan(connection, visitor, startrow, type, false);
+      final byte[] row, final int rowLimit)
-  }
+      throws IOException {
 
-  /**
+    byte[] startRow = null;
-   * Performs a full scan of a catalog table.
+    byte[] stopRow = null;
-   * @param connection connection we're using
+    if (tableName != null) {
-   * @param visitor Visitor invoked against each row.
+      startRow =
-   * @param startrow Where to start the scan. Pass null if want to begin scan
+          getTableStartRowForMeta(tableName, QueryType.REGION);
-   * at first row.
+      if (row != null) {
-   * @param type scanned part of meta
+        HRegionInfo closestRi =
-   * @param raw read raw data including Delete tumbstones
+            getClosestRegionInfo(connection, tableName, row);
-   * <code>hbase:meta</code>, the default (pass false to scan hbase:meta)
+        startRow = HRegionInfo
-   * @throws IOException
+            .createRegionName(tableName, closestRi.getStartKey(), HConstants.ZEROES, false);
-   */
+      }
-  public static void fullScan(Connection connection,
+      stopRow =
-      final Visitor visitor, @Nullable final byte[] startrow, QueryType type, boolean raw)
+          getTableStopRowForMeta(tableName, QueryType.REGION);
-  throws IOException {
-    Scan scan = new Scan();
-    scan.setRaw(raw);
-    if (startrow != null) scan.setStartRow(startrow);
-    if (startrow == null) {
-      int caching = connection.getConfiguration()
-          .getInt(HConstants.HBASE_META_SCANNER_CACHING, 100);
-      scan.setCaching(caching);
     }
+    scanMeta(connection, startRow, stopRow, QueryType.REGION, rowLimit, visitor);
+  }
+
+
+  /**
+   * Performs a scan of META table.
+   * @param connection connection we're using
+   * @param startRow Where to start the scan. Pass null if want to begin scan
+   *                 at first row.
+   * @param stopRow Where to stop the scan. Pass null if want to scan all rows
+   *                from the start one
+   * @param type scanned part of meta
+   * @param maxRows maximum rows to return
+   * @param visitor Visitor invoked against each row.
+   * @throws IOException
+   */
+  public static void scanMeta(Connection connection,
+      @Nullable final byte[] startRow, @Nullable final byte[] stopRow,
+      QueryType type, int maxRows, final Visitor visitor)
+  throws IOException {
+    int rowUpperLimit = maxRows > 0 ? maxRows : Integer.MAX_VALUE;
+    Scan scan = getMetaScan(connection, rowUpperLimit);
+
     for (byte[] family : type.getFamilies()) {
       scan.addFamily(family);
     }
-    Table metaTable = getMetaHTable(connection);
+    if (startRow != null) scan.setStartRow(startRow);
-    ResultScanner scanner = null;
+    if (stopRow != null) scan.setStopRow(stopRow);
-    try {
+
-      scanner = metaTable.getScanner(scan);
+    if (LOG.isTraceEnabled()) {
-      Result data;
+      LOG.trace("Scanning META"
-      while((data = scanner.next()) != null) {
+          + " starting at row=" + Bytes.toStringBinary(startRow)
-        if (data.isEmpty()) continue;
+          + " stopping at row=" + Bytes.toStringBinary(stopRow)
-        // Break if visit returns false.
+          + " for max=" + rowUpperLimit
-        if (!visitor.visit(data)) break;
+          + " with caching=" + scan.getCaching());
+    }
+
+    int currentRow = 0;
+    try (Table metaTable = getMetaHTable(connection)) {
+      try (ResultScanner scanner = metaTable.getScanner(scan)) {
+        Result data;
+        while ((data = scanner.next()) != null) {
+          if (data.isEmpty()) continue;
+          // Break if visit returns false.
+          if (!visitor.visit(data)) break;
+          if (++currentRow >= rowUpperLimit) break;
+        }
       }
-    } finally {
+    }
-      if (scanner != null) scanner.close();
+    if (visitor != null && visitor instanceof Closeable) {
-      metaTable.close();
+      try {
+        ((Closeable) visitor).close();
+      } catch (Throwable t) {
+        ExceptionUtil.rethrowIfInterrupt(t);
+        LOG.debug("Got exception in closing the meta scanner visitor", t);
+      }
+    }
+  }
+
+  /**
+   * @return Get closest metatable region row to passed <code>row</code>
+   * @throws java.io.IOException
+   */
+  @Nonnull
+  public static HRegionInfo getClosestRegionInfo(Connection connection,
+      @Nonnull final TableName tableName,
+      @Nonnull final byte[] row)
+      throws IOException {
+    byte[] searchRow = HRegionInfo.createRegionName(tableName, row, HConstants.NINES, false);
+    Scan scan = getMetaScan(connection, 1);
+    scan.setReversed(true);
+    scan.setStartRow(searchRow);
+    try (ResultScanner resultScanner = getMetaHTable(connection).getScanner(scan)) {
+      Result result = resultScanner.next();
+      if (result == null) {
+        throw new TableNotFoundException("Cannot find row in META " +
+            " for table: " + tableName + ", row=" + Bytes.toStringBinary(row));
+      }
+      HRegionInfo regionInfo = getHRegionInfo(result);
+      if (regionInfo == null) {
+        throw new IOException("HRegionInfo was null or empty in Meta for " +
+            tableName + ", row=" + Bytes.toStringBinary(row));
+      }
+      return regionInfo;
     }
   }
 
@@ -976,6 +1146,12 @@ public class MetaTableAccessor {
     boolean visit(final Result r) throws IOException;
   }
 
+  /**
+   * Implementations 'visit' a catalog table row but with close() at the end.
+   */
+  public interface CloseableVisitor extends Visitor, Closeable {
+  }
+
   /**
    * A {@link Visitor} that collects content out of passed {@link Result}.
    */
@@ -1009,6 +1185,59 @@ public class MetaTableAccessor {
     }
   }
 
+  /**
+   * A Visitor that skips offline regions and split parents
+   */
+  public static abstract class DefaultVisitorBase implements Visitor {
+
+    public DefaultVisitorBase() {
+      super();
+    }
+
+    public abstract boolean visitInternal(Result rowResult) throws IOException;
+
+    @Override
+    public boolean visit(Result rowResult) throws IOException {
+      HRegionInfo info = getHRegionInfo(rowResult);
+      if (info == null) {
+        return true;
+      }
+
+      //skip over offline and split regions
+      if (!(info.isOffline() || info.isSplit())) {
+        return visitInternal(rowResult);
+      }
+      return true;
+    }
+  }
+
+  /**
+   * A Visitor for a table. Provides a consistent view of the table's
+   * hbase:meta entries during concurrent splits (see HBASE-5986 for details). This class
+   * does not guarantee ordered traversal of meta entries, and can block until the
+   * hbase:meta entries for daughters are available during splits.
+   */
+  public static abstract class TableVisitorBase extends DefaultVisitorBase {
+    private TableName tableName;
+
+    public TableVisitorBase(TableName tableName) {
+      super();
+      this.tableName = tableName;
+    }
+
+    @Override
+    public final boolean visit(Result rowResult) throws IOException {
+      HRegionInfo info = getHRegionInfo(rowResult);
+      if (info == null) {
+        return true;
+      }
+      if (!(info.getTable().equals(tableName))) {
+        return false;
+      }
+      return super.visit(rowResult);
+    }
+  }
+
   /**
    * Count regions in <code>hbase:meta</code> for passed table.
    * @param c Configuration object
@@ -1113,6 +1342,9 @@ public class MetaTableAccessor {
    */
   private static void put(final Table t, final Put p) throws IOException {
     try {
+      if (METALOG.isDebugEnabled()) {
+        METALOG.debug(mutationToString(p));
+      }
       t.put(p);
     } finally {
       t.close();
@@ -1129,6 +1361,9 @@ public class MetaTableAccessor {
     throws IOException {
     Table t = getMetaHTable(connection);
     try {
+      if (METALOG.isDebugEnabled()) {
+        METALOG.debug(mutationsToString(ps));
+      }
       t.put(ps);
     } finally {
       t.close();
@@ -1158,6 +1393,9 @@ public class MetaTableAccessor {
     throws IOException {
     Table t = getMetaHTable(connection);
     try {
+      if (METALOG.isDebugEnabled()) {
+        METALOG.debug(mutationsToString(deletes));
+      }
       t.delete(deletes);
     } finally {
       t.close();
@@ -1202,7 +1440,10 @@ public class MetaTableAccessor {
     throws IOException {
     Table t = getMetaHTable(connection);
     try {
-      t.batch(mutations);
+      if (METALOG.isDebugEnabled()) {
+        METALOG.debug(mutationsToString(mutations));
+      }
+      t.batch(mutations, new Object[mutations.size()]);
     } catch (InterruptedException e) {
       InterruptedIOException ie = new InterruptedIOException(e.getMessage());
       ie.initCause(e);
@@ -1253,6 +1494,9 @@ public class MetaTableAccessor {
     Put put = makePutFromRegionInfo(regionInfo);
     addDaughtersToPut(put, splitA, splitB);
     meta.put(put);
+    if (METALOG.isDebugEnabled()) {
+      METALOG.debug(mutationToString(put));
+    }
     if (LOG.isDebugEnabled()) {
       LOG.debug("Added " + regionInfo.getRegionNameAsString());
     }
@@ -1464,6 +1708,9 @@ public class MetaTableAccessor {
     CoprocessorRpcChannel channel = table.coprocessorService(row);
     MultiRowMutationProtos.MutateRowsRequest.Builder mmrBuilder
       = MultiRowMutationProtos.MutateRowsRequest.newBuilder();
+    if (METALOG.isDebugEnabled()) {
+      METALOG.debug(mutationsToString(mutations));
+    }
     for (Mutation mutation : mutations) {
       if (mutation instanceof Put) {
         mmrBuilder.addMutationRequest(ProtobufUtil.toMutation(
@@ -1659,4 +1906,28 @@ public class MetaTableAccessor {
     p.addImmutable(getCatalogFamily(), getSeqNumColumn(replicaId), now, null);
     return p;
   }
+
+  private static String mutationsToString(Mutation ... mutations) throws IOException {
+    StringBuilder sb = new StringBuilder();
+    String prefix = "";
+    for (Mutation mutation : mutations) {
+      sb.append(prefix).append(mutationToString(mutation));
+      prefix = ", ";
+    }
+    return sb.toString();
+  }
+
+  private static String mutationsToString(List<? extends Mutation> mutations) throws IOException {
+    StringBuilder sb = new StringBuilder();
+    String prefix = "";
+    for (Mutation mutation : mutations) {
+      sb.append(prefix).append(mutationToString(mutation));
+      prefix = ", ";
+    }
+    return sb.toString();
+  }
+
+  private static String mutationToString(Mutation p) throws IOException {
+    return p.getClass().getSimpleName() + p.toJSON();
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/RegionLoad.java

@@ -20,9 +20,12 @@
 
 package org.apache.hadoop.hbase;
 
+import java.util.List;
+
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos;
+import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos.StoreSequenceId;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Strings;
 
@@ -153,6 +156,13 @@ public class RegionLoad {
     return regionLoadPB.getCompleteSequenceId();
   }
 
+  /**
+   * @return completed sequence id per store.
+   */
+  public List<StoreSequenceId> getStoreCompleteSequenceId() {
+    return regionLoadPB.getStoreCompleteSequenceIdList();
+  }
+
   /**
    * @return the uncompressed size of the storefiles in MB.
    */

hbase-client/src/main/java/org/apache/hadoop/hbase/RegionLocations.java

@@ -21,6 +21,7 @@ package org.apache.hadoop.hbase;
 import java.util.Collection;
 
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.client.RegionReplicaUtil;
 import org.apache.hadoop.hbase.util.Bytes;
 
 /**
@@ -200,9 +201,15 @@ public class RegionLocations {
     // in case of region replication going down, we might have a leak here.
     int max = other.locations.length;
 
+    HRegionInfo regionInfo = null;
     for (int i = 0; i < max; i++) {
       HRegionLocation thisLoc = this.getRegionLocation(i);
       HRegionLocation otherLoc = other.getRegionLocation(i);
+      if (regionInfo == null && otherLoc != null && otherLoc.getRegionInfo() != null) {
+        // regionInfo is the first non-null HRI from other RegionLocations. We use it to ensure that
+        // all replica region infos belong to the same region with same region id.
+        regionInfo = otherLoc.getRegionInfo();
+      }
 
       HRegionLocation selectedLoc = selectRegionLocation(thisLoc,
         otherLoc, true, false);
@@ -218,6 +225,18 @@ public class RegionLocations {
       }
     }
 
+    // ensure that all replicas share the same start code. Otherwise delete them
+    if (newLocations != null && regionInfo != null) {
+      for (int i=0; i < newLocations.length; i++) {
+        if (newLocations[i] != null) {
+          if (!RegionReplicaUtil.isReplicasForSameRegion(regionInfo,
+            newLocations[i].getRegionInfo())) {
+            newLocations[i] = null;
+          }
+        }
+      }
+    }
+
     return newLocations == null ? this : new RegionLocations(newLocations);
   }
 
@@ -264,6 +283,15 @@ public class RegionLocations {
     HRegionLocation[] newLocations = new HRegionLocation[Math.max(locations.length, replicaId +1)];
     System.arraycopy(locations, 0, newLocations, 0, locations.length);
     newLocations[replicaId] = location;
+    // ensure that all replicas share the same start code. Otherwise delete them
+    for (int i=0; i < newLocations.length; i++) {
+      if (newLocations[i] != null) {
+        if (!RegionReplicaUtil.isReplicasForSameRegion(location.getRegionInfo(),
+          newLocations[i].getRegionInfo())) {
+          newLocations[i] = null;
+        }
+      }
+    }
     return new RegionLocations(newLocations);
   }
 

hbase-client/src/main/java/org/apache/hadoop/hbase/ServerLoad.java

@@ -28,8 +28,11 @@ import java.util.TreeSet;
 
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
+import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.Coprocessor;
+import org.apache.hadoop.hbase.replication.ReplicationLoadSink;
+import org.apache.hadoop.hbase.replication.ReplicationLoadSource;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Strings;
 
@@ -52,7 +55,7 @@ public class ServerLoad {
   private int totalStaticBloomSizeKB = 0;
   private long totalCompactingKVs = 0;
   private long currentCompactedKVs = 0;
-  
+
   public ServerLoad(ClusterStatusProtos.ServerLoad serverLoad) {
     this.serverLoad = serverLoad;
     for (ClusterStatusProtos.RegionLoad rl: serverLoad.getRegionLoadsList()) {
@@ -70,7 +73,7 @@ public class ServerLoad {
       totalCompactingKVs += rl.getTotalCompactingKVs();
       currentCompactedKVs += rl.getCurrentCompactedKVs();
     }
-    
+
   }
 
   // NOTE: Function name cannot start with "get" because then an OpenDataException is thrown because
@@ -177,6 +180,26 @@ public class ServerLoad {
     return serverLoad.getInfoServerPort();
   }
 
+  /**
+   * Call directly from client such as hbase shell
+   * @return the list of ReplicationLoadSource
+   */
+  public List<ReplicationLoadSource> getReplicationLoadSourceList() {
+    return ProtobufUtil.toReplicationLoadSourceList(serverLoad.getReplLoadSourceList());
+  }
+
+  /**
+   * Call directly from client such as hbase shell
+   * @return ReplicationLoadSink
+   */
+  public ReplicationLoadSink getReplicationLoadSink() {
+    if (serverLoad.hasReplLoadSink()) {
+      return ProtobufUtil.toReplicationLoadSink(serverLoad.getReplLoadSink());
+    } else {
+      return null;
+    }
+  }
+
   /**
    * Originally, this method factored in the effect of requests going to the
    * server as well. However, this does not interact very well with the current

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractClientScanner.java

@@ -23,14 +23,12 @@ import java.util.Iterator;
 
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.client.metrics.ScanMetrics;
-import org.apache.hadoop.hbase.util.Bytes;
 
 /**
  * Helper class for custom client scanners.
  */
 @InterfaceAudience.Private
 public abstract class AbstractClientScanner implements ResultScanner {
-
   protected ScanMetrics scanMetrics;
 
   /**
@@ -38,14 +36,19 @@ public abstract class AbstractClientScanner implements ResultScanner {
    */
   protected void initScanMetrics(Scan scan) {
     // check if application wants to collect scan metrics
-    byte[] enableMetrics = scan.getAttribute(
+    if (scan.isScanMetricsEnabled()) {
-      Scan.SCAN_ATTRIBUTES_METRICS_ENABLE);
-    if (enableMetrics != null && Bytes.toBoolean(enableMetrics)) {
       scanMetrics = new ScanMetrics();
     }
   }
 
-  // TODO: should this be at ResultScanner? ScanMetrics is not public API it seems.
+  /**
+   * Used internally accumulating metrics on scan. To
+   * enable collection of metrics on a Scanner, call {@link Scan#setScanMetricsEnabled(boolean)}.
+   * These metrics are cleared at key transition points. Metrics are accumulated in the
+   * {@link Scan} object itself.
+   * @see Scan#getScanMetrics()
+   * @return Returns the running {@link ScanMetrics} instance or null if scan metrics not enabled.
+   */
   public ScanMetrics getScanMetrics() {
     return scanMetrics;
   }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java

@@ -702,6 +702,13 @@ public interface Admin extends Abortable, Closeable {
    */
   boolean balancer() throws IOException;
 
+  /**
+   * Query the current state of the balancer
+   *
+   * @return true if the balancer is enabled, false otherwise.
+   */
+  boolean isBalancerEnabled() throws IOException;
+
   /**
    * Enable/Disable the catalog janitor
    *

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncProcess.java

@@ -744,7 +744,7 @@ class AsyncProcess {
 
     private final Batch.Callback<CResult> callback;
     private final BatchErrors errors;
-    private final ConnectionManager.ServerErrorTracker errorsByServer;
+    private final ConnectionImplementation.ServerErrorTracker errorsByServer;
     private final ExecutorService pool;
     private final Set<MultiServerCallable<Row>> callsInProgress;
 
@@ -1743,8 +1743,8 @@ class AsyncProcess {
    * We may benefit from connection-wide tracking of server errors.
    * @return ServerErrorTracker to use, null if there is no ServerErrorTracker on this connection
    */
-  protected ConnectionManager.ServerErrorTracker createServerErrorTracker() {
+  protected ConnectionImplementation.ServerErrorTracker createServerErrorTracker() {
-    return new ConnectionManager.ServerErrorTracker(
+    return new ConnectionImplementation.ServerErrorTracker(
         this.serverTrackerTimeout, this.numTries);
   }
 

hbase-client/src/main/java/org/apache/hadoop/hbase/client/BufferedMutator.java

@@ -60,7 +60,7 @@ import java.util.List;
  * @see Connection
  * @since 1.0.0
  */
-@InterfaceAudience.Private
+@InterfaceAudience.Public
 @InterfaceStability.Evolving
 public interface BufferedMutator extends Closeable {
   /**
@@ -122,6 +122,8 @@ public interface BufferedMutator extends Closeable {
   /**
    * Listens for asynchronous exceptions on a {@link BufferedMutator}.
    */
+  @InterfaceAudience.Public
+  @InterfaceStability.Evolving
   interface ExceptionListener {
     public void onException(RetriesExhaustedWithDetailsException exception,
         BufferedMutator mutator) throws RetriesExhaustedWithDetailsException;

hbase-client/src/main/java/org/apache/hadoop/hbase/client/BufferedMutatorImpl.java

@@ -42,7 +42,7 @@ import java.util.concurrent.TimeUnit;
  * @since 1.0.0
  */
 @InterfaceAudience.Private
-@InterfaceStability.Stable
+@InterfaceStability.Evolving
 public class BufferedMutatorImpl implements BufferedMutator {
 
   private static final Log LOG = LogFactory.getLog(BufferedMutatorImpl.class);

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClientScanner.java

@@ -19,7 +19,10 @@ package org.apache.hadoop.hbase.client;
 
 import java.io.IOException;
 import java.io.InterruptedIOException;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.LinkedList;
+import java.util.List;
 import java.util.concurrent.ExecutorService;
 
 import org.apache.commons.logging.Log;
@@ -44,8 +47,6 @@ import org.apache.hadoop.hbase.util.Bytes;
 
 import com.google.common.annotations.VisibleForTesting;
 
-import static org.apache.hadoop.hbase.client.ReversedClientScanner.createClosestRowBefore;
-
 /**
  * Implements the scanner interface for the HBase client.
  * If there are multiple regions in a table, this scanner will iterate
@@ -54,6 +55,9 @@ import static org.apache.hadoop.hbase.client.ReversedClientScanner.createClosest
 @InterfaceAudience.Private
 public class ClientScanner extends AbstractClientScanner {
     private final Log LOG = LogFactory.getLog(this.getClass());
+    // A byte array in which all elements are the max byte, and it is used to
+    // construct closest front row
+    static byte[] MAX_BYTE_ARRAY = Bytes.createMaxByteArray(9);
     protected Scan scan;
     protected boolean closed = false;
     // Current region scanner is against.  Gets cleared if current region goes
@@ -61,6 +65,18 @@ public class ClientScanner extends AbstractClientScanner {
     protected HRegionInfo currentRegion = null;
     protected ScannerCallableWithReplicas callable = null;
     protected final LinkedList<Result> cache = new LinkedList<Result>();
+    /**
+     * A list of partial results that have been returned from the server. This list should only
+     * contain results if this scanner does not have enough partial results to form the complete
+     * result.
+     */
+    protected final LinkedList<Result> partialResults = new LinkedList<Result>();
+    /**
+     * The row for which we are accumulating partial Results (i.e. the row of the Results stored
+     * inside partialResults). Changes to partialResultsRow and partialResults are kept in sync
+     * via the methods {@link #addToPartialResults(Result)} and {@link #clearPartialResults()}
+     */
+    protected byte[] partialResultsRow = null;
     protected final int caching;
     protected long lastNext;
     // Keep lastResult returned successfully in case we have to reset scanner.
@@ -285,7 +301,7 @@ public class ClientScanner extends AbstractClientScanner {
     return callable.isAnyRPCcancelled();
   }
 
-  static Result[] call(ScannerCallableWithReplicas callable,
+  Result[] call(ScannerCallableWithReplicas callable,
       RpcRetryingCaller<Result[]> caller, int scannerTimeout)
       throws IOException, RuntimeException {
     if (Thread.interrupted()) {
@@ -317,9 +333,9 @@ public class ClientScanner extends AbstractClientScanner {
      * machine; for scan/map reduce scenarios, we will have multiple scans running at the same time.
      *
      * By default, scan metrics are disabled; if the application wants to collect them, this
-     * behavior can be turned on by calling calling:
+     * behavior can be turned on by calling calling {@link Scan#setScanMetricsEnabled(boolean)}
-     *
+     * 
-     * scan.setAttribute(SCAN_ATTRIBUTES_METRICS_ENABLE, Bytes.toBytes(Boolean.TRUE))
+     * <p>This invocation clears the scan metrics. Metrics are aggregated in the Scan instance.
      */
     protected void writeScanMetrics() {
       if (this.scanMetrics == null || scanMetricsPublished) {
@@ -337,112 +353,7 @@ public class ClientScanner extends AbstractClientScanner {
         return null;
       }
       if (cache.size() == 0) {
-        Result [] values = null;
+        loadCache();
-        long remainingResultSize = maxScannerResultSize;
-        int countdown = this.caching;
-        // We need to reset it if it's a new callable that was created
-        // with a countdown in nextScanner
-        callable.setCaching(this.caching);
-        // This flag is set when we want to skip the result returned.  We do
-        // this when we reset scanner because it split under us.
-        boolean retryAfterOutOfOrderException  = true;
-        do {
-          try {
-            // Server returns a null values if scanning is to stop.  Else,
-            // returns an empty array if scanning is to go on and we've just
-            // exhausted current region.
-            values = call(callable, caller, scannerTimeout);
-            // When the replica switch happens, we need to do certain operations
-            // again. The callable will openScanner with the right startkey
-            // but we need to pick up from there. Bypass the rest of the loop
-            // and let the catch-up happen in the beginning of the loop as it
-            // happens for the cases where we see exceptions. Since only openScanner
-            // would have happened, values would be null
-            if (values == null && callable.switchedToADifferentReplica()) {
-              this.currentRegion = callable.getHRegionInfo();
-              continue;
-            }
-            retryAfterOutOfOrderException  = true;
-          } catch (DoNotRetryIOException e) {
-            // DNRIOEs are thrown to make us break out of retries.  Some types of DNRIOEs want us
-            // to reset the scanner and come back in again.
-            if (e instanceof UnknownScannerException) {
-              long timeout = lastNext + scannerTimeout;
-              // If we are over the timeout, throw this exception to the client wrapped in
-              // a ScannerTimeoutException. Else, it's because the region moved and we used the old
-              // id against the new region server; reset the scanner.
-              if (timeout < System.currentTimeMillis()) {
-                long elapsed = System.currentTimeMillis() - lastNext;
-                ScannerTimeoutException ex = new ScannerTimeoutException(
-                    elapsed + "ms passed since the last invocation, " +
-                        "timeout is currently set to " + scannerTimeout);
-                ex.initCause(e);
-                throw ex;
-              }
-            } else {
-              // If exception is any but the list below throw it back to the client; else setup
-              // the scanner and retry.
-              Throwable cause = e.getCause();
-              if ((cause != null && cause instanceof NotServingRegionException) ||
-                (cause != null && cause instanceof RegionServerStoppedException) ||
-                e instanceof OutOfOrderScannerNextException) {
-                // Pass
-                // It is easier writing the if loop test as list of what is allowed rather than
-                // as a list of what is not allowed... so if in here, it means we do not throw.
-              } else {
-                throw e;
-              }
-            }
-            // Else, its signal from depths of ScannerCallable that we need to reset the scanner.
-            if (this.lastResult != null) {
-              // The region has moved. We need to open a brand new scanner at
-              // the new location.
-              // Reset the startRow to the row we've seen last so that the new
-              // scanner starts at the correct row. Otherwise we may see previously
-              // returned rows again.
-              // (ScannerCallable by now has "relocated" the correct region)
-              if(scan.isReversed()){
-                scan.setStartRow(createClosestRowBefore(lastResult.getRow()));
-              }else {
-                scan.setStartRow(Bytes.add(lastResult.getRow(), new byte[1]));
-              }
-            }
-            if (e instanceof OutOfOrderScannerNextException) {
-              if (retryAfterOutOfOrderException) {
-                retryAfterOutOfOrderException = false;
-              } else {
-                // TODO: Why wrap this in a DNRIOE when it already is a DNRIOE?
-                throw new DoNotRetryIOException("Failed after retry of " +
-                  "OutOfOrderScannerNextException: was there a rpc timeout?", e);
-              }
-            }
-            // Clear region.
-            this.currentRegion = null;
-            // Set this to zero so we don't try and do an rpc and close on remote server when
-            // the exception we got was UnknownScanner or the Server is going down.
-            callable = null;
-            // This continue will take us to while at end of loop where we will set up new scanner.
-            continue;
-          }
-          long currentTime = System.currentTimeMillis();
-          if (this.scanMetrics != null) {
-            this.scanMetrics.sumOfMillisSecBetweenNexts.addAndGet(currentTime-lastNext);
-          }
-          lastNext = currentTime;
-          if (values != null && values.length > 0) {
-            for (Result rs : values) {
-              cache.add(rs);
-              // We don't make Iterator here
-              for (Cell cell : rs.rawCells()) {
-                remainingResultSize -= CellUtil.estimatedHeapSizeOf(cell);
-              }
-              countdown--;
-              this.lastResult = rs;
-            }
-          }
-          // Values == null means server-side filter has determined we must STOP
-        } while (remainingResultSize > 0 && countdown > 0 &&
-            possiblyNextScanner(countdown, values == null));
       }
 
       if (cache.size() > 0) {
@@ -454,6 +365,309 @@ public class ClientScanner extends AbstractClientScanner {
       return null;
     }
 
+  @VisibleForTesting
+  public int getCacheSize() {
+    return cache != null ? cache.size() : 0;
+  }
+
+  /**
+   * Contact the servers to load more {@link Result}s in the cache.
+   */
+  protected void loadCache() throws IOException {
+    Result[] values = null;
+    long remainingResultSize = maxScannerResultSize;
+    int countdown = this.caching;
+
+    // We need to reset it if it's a new callable that was created
+    // with a countdown in nextScanner
+    callable.setCaching(this.caching);
+    // This flag is set when we want to skip the result returned. We do
+    // this when we reset scanner because it split under us.
+    boolean retryAfterOutOfOrderException = true;
+    // We don't expect that the server will have more results for us if
+    // it doesn't tell us otherwise. We rely on the size or count of results
+    boolean serverHasMoreResults = false;
+    do {
+      try {
+        // Server returns a null values if scanning is to stop. Else,
+        // returns an empty array if scanning is to go on and we've just
+        // exhausted current region.
+        values = call(callable, caller, scannerTimeout);
+
+        // When the replica switch happens, we need to do certain operations
+        // again. The callable will openScanner with the right startkey
+        // but we need to pick up from there. Bypass the rest of the loop
+        // and let the catch-up happen in the beginning of the loop as it
+        // happens for the cases where we see exceptions. Since only openScanner
+        // would have happened, values would be null
+        if (values == null && callable.switchedToADifferentReplica()) {
+          // Any accumulated partial results are no longer valid since the callable will
+          // openScanner with the correct startkey and we must pick up from there
+          clearPartialResults();
+          this.currentRegion = callable.getHRegionInfo();
+          continue;
+        }
+        retryAfterOutOfOrderException = true;
+      } catch (DoNotRetryIOException e) {
+        // An exception was thrown which makes any partial results that we were collecting
+        // invalid. The scanner will need to be reset to the beginning of a row.
+        clearPartialResults();
+
+        // DNRIOEs are thrown to make us break out of retries. Some types of DNRIOEs want us
+        // to reset the scanner and come back in again.
+        if (e instanceof UnknownScannerException) {
+          long timeout = lastNext + scannerTimeout;
+          // If we are over the timeout, throw this exception to the client wrapped in
+          // a ScannerTimeoutException. Else, it's because the region moved and we used the old
+          // id against the new region server; reset the scanner.
+          if (timeout < System.currentTimeMillis()) {
+            long elapsed = System.currentTimeMillis() - lastNext;
+            ScannerTimeoutException ex =
+                new ScannerTimeoutException(elapsed + "ms passed since the last invocation, "
+                    + "timeout is currently set to " + scannerTimeout);
+            ex.initCause(e);
+            throw ex;
+          }
+        } else {
+          // If exception is any but the list below throw it back to the client; else setup
+          // the scanner and retry.
+          Throwable cause = e.getCause();
+          if ((cause != null && cause instanceof NotServingRegionException) ||
+              (cause != null && cause instanceof RegionServerStoppedException) ||
+              e instanceof OutOfOrderScannerNextException) {
+            // Pass
+            // It is easier writing the if loop test as list of what is allowed rather than
+            // as a list of what is not allowed... so if in here, it means we do not throw.
+          } else {
+            throw e;
+          }
+        }
+        // Else, its signal from depths of ScannerCallable that we need to reset the scanner.
+        if (this.lastResult != null) {
+          // The region has moved. We need to open a brand new scanner at
+          // the new location.
+          // Reset the startRow to the row we've seen last so that the new
+          // scanner starts at the correct row. Otherwise we may see previously
+          // returned rows again.
+          // (ScannerCallable by now has "relocated" the correct region)
+          if (scan.isReversed()) {
+            scan.setStartRow(createClosestRowBefore(lastResult.getRow()));
+          } else {
+            scan.setStartRow(Bytes.add(lastResult.getRow(), new byte[1]));
+          }
+        }
+        if (e instanceof OutOfOrderScannerNextException) {
+          if (retryAfterOutOfOrderException) {
+            retryAfterOutOfOrderException = false;
+          } else {
+            // TODO: Why wrap this in a DNRIOE when it already is a DNRIOE?
+            throw new DoNotRetryIOException("Failed after retry of " +
+                "OutOfOrderScannerNextException: was there a rpc timeout?", e);
+          }
+        }
+        // Clear region.
+        this.currentRegion = null;
+        // Set this to zero so we don't try and do an rpc and close on remote server when
+        // the exception we got was UnknownScanner or the Server is going down.
+        callable = null;
+
+        // This continue will take us to while at end of loop where we will set up new scanner.
+        continue;
+      }
+      long currentTime = System.currentTimeMillis();
+      if (this.scanMetrics != null) {
+        this.scanMetrics.sumOfMillisSecBetweenNexts.addAndGet(currentTime - lastNext);
+      }
+      lastNext = currentTime;
+      // Groom the array of Results that we received back from the server before adding that
+      // Results to the scanner's cache. If partial results are not allowed to be seen by the
+      // caller, all book keeping will be performed within this method.
+      List<Result> resultsToAddToCache = getResultsToAddToCache(values);
+      if (!resultsToAddToCache.isEmpty()) {
+        for (Result rs : resultsToAddToCache) {
+          cache.add(rs);
+          // We don't make Iterator here
+          for (Cell cell : rs.rawCells()) {
+            remainingResultSize -= CellUtil.estimatedHeapSizeOf(cell);
+          }
+          countdown--;
+          this.lastResult = rs;
+        }
+      }
+      // We expect that the server won't have more results for us when we exhaust
+      // the size (bytes or count) of the results returned. If the server *does* inform us that
+      // there are more results, we want to avoid possiblyNextScanner(...). Only when we actually
+      // get results is the moreResults context valid.
+      if (null != values && values.length > 0 && callable.hasMoreResultsContext()) {
+        // Only adhere to more server results when we don't have any partialResults
+        // as it keeps the outer loop logic the same.
+        serverHasMoreResults = callable.getServerHasMoreResults() & partialResults.isEmpty();
+      }
+      // Values == null means server-side filter has determined we must STOP
+      // !partialResults.isEmpty() means that we are still accumulating partial Results for a
+      // row. We should not change scanners before we receive all the partial Results for that
+      // row.
+    } while (remainingResultSize > 0 && countdown > 0 && !serverHasMoreResults
+        && (!partialResults.isEmpty() || possiblyNextScanner(countdown, values == null)));
+  }
+
+  /**
+   * This method ensures all of our book keeping regarding partial results is kept up to date. This
+   * method should be called once we know that the results we received back from the RPC request do
+   * not contain errors. We return a list of results that should be added to the cache. In general,
+   * this list will contain all NON-partial results from the input array (unless the client has
+   * specified that they are okay with receiving partial results)
+   * @return the list of results that should be added to the cache.
+   * @throws IOException
+   */
+  protected List<Result> getResultsToAddToCache(Result[] resultsFromServer) throws IOException {
+    int resultSize = resultsFromServer != null ? resultsFromServer.length : 0;
+    List<Result> resultsToAddToCache = new ArrayList<Result>(resultSize);
+
+    final boolean isBatchSet = scan != null && scan.getBatch() > 0;
+    final boolean allowPartials = scan != null && scan.getAllowPartialResults();
+
+    // If the caller has indicated in their scan that they are okay with seeing partial results,
+    // then simply add all results to the list. Note that since scan batching also returns results
+    // for a row in pieces we treat batch being set as equivalent to allowing partials. The
+    // implication of treating batching as equivalent to partial results is that it is possible
+    // the caller will receive a result back where the number of cells in the result is less than
+    // the batch size even though it may not be the last group of cells for that row.
+    if (allowPartials || isBatchSet) {
+      addResultsToList(resultsToAddToCache, resultsFromServer, 0, resultsFromServer.length);
+      return resultsToAddToCache;
+    }
+
+    // If no results were returned it indicates that we have the all the partial results necessary
+    // to construct the complete result.
+    if (resultsFromServer == null || resultsFromServer.length == 0) {
+      if (!partialResults.isEmpty()) {
+        resultsToAddToCache.add(Result.createCompleteResult(partialResults));
+        clearPartialResults();
+      }
+
+      return resultsToAddToCache;
+    }
+
+    // In every RPC response there should be at most a single partial result. Furthermore, if
+    // there is a partial result, it is guaranteed to be in the last position of the array.
+    Result last = resultsFromServer[resultsFromServer.length - 1];
+    Result partial = last.isPartial() ? last : null;
+
+    if (LOG.isTraceEnabled()) {
+      StringBuilder sb = new StringBuilder();
+      sb.append("number results from RPC: ").append(resultsFromServer.length).append(",");
+      sb.append("partial != null: ").append(partial != null).append(",");
+      sb.append("number of partials so far: ").append(partialResults.size());
+      LOG.trace(sb.toString());
+    }
+
+    // There are three possibilities cases that can occur while handling partial results
+    //
+    // 1. (partial != null && partialResults.isEmpty())
+    // This is the first partial result that we have received. It should be added to
+    // the list of partialResults and await the next RPC request at which point another
+    // portion of the complete result will be received
+    //
+    // 2. !partialResults.isEmpty()
+    // Since our partialResults list is not empty it means that we have been accumulating partial
+    // Results for a particular row. We cannot form the complete/whole Result for that row until
+    // all partials for the row have been received. Thus we loop through all of the Results
+    // returned from the server and determine whether or not all partial Results for the row have
+    // been received. We know that we have received all of the partial Results for the row when:
+    // i) We notice a row change in the Results
+    // ii) We see a Result for the partial row that is NOT marked as a partial Result
+    //
+    // 3. (partial == null && partialResults.isEmpty())
+    // Business as usual. We are not accumulating partial results and there wasn't a partial result
+    // in the RPC response. This means that all of the results we received from the server are
+    // complete and can be added directly to the cache
+    if (partial != null && partialResults.isEmpty()) {
+      addToPartialResults(partial);
+
+      // Exclude the last result, it's a partial
+      addResultsToList(resultsToAddToCache, resultsFromServer, 0, resultsFromServer.length - 1);
+    } else if (!partialResults.isEmpty()) {
+      for (int i = 0; i < resultsFromServer.length; i++) {
+        Result result = resultsFromServer[i];
+
+        // This result is from the same row as the partial Results. Add it to the list of partials
+        // and check if it was the last partial Result for that row
+        if (Bytes.equals(partialResultsRow, result.getRow())) {
+          addToPartialResults(result);
+
+          // If the result is not a partial, it is a signal to us that it is the last Result we
+          // need to form the complete Result client-side
+          if (!result.isPartial()) {
+            resultsToAddToCache.add(Result.createCompleteResult(partialResults));
+            clearPartialResults();
+          }
+        } else {
+          // The row of this result differs from the row of the partial results we have received so
+          // far. If our list of partials isn't empty, this is a signal to form the complete Result
+          // since the row has now changed
+          if (!partialResults.isEmpty()) {
+            resultsToAddToCache.add(Result.createCompleteResult(partialResults));
+            clearPartialResults();
+          }
+
+          // It's possible that in one response from the server we receive the final partial for
+          // one row and receive a partial for a different row. Thus, make sure that all Results
+          // are added to the proper list
+          if (result.isPartial()) {
+            addToPartialResults(result);
+          } else {
+            resultsToAddToCache.add(result);
+          }
+        }
+      }
+    } else { // partial == null && partialResults.isEmpty() -- business as usual
+      addResultsToList(resultsToAddToCache, resultsFromServer, 0, resultsFromServer.length);
+    }
+
+    return resultsToAddToCache;
+  }
+
+  /**
+   * A convenience method for adding a Result to our list of partials. This method ensure that only
+   * Results that belong to the same row as the other partials can be added to the list.
+   * @param result The result that we want to add to our list of partial Results
+   * @throws IOException
+   */
+  private void addToPartialResults(final Result result) throws IOException {
+    final byte[] row = result.getRow();
+    if (partialResultsRow != null && !Bytes.equals(row, partialResultsRow)) {
+      throw new IOException("Partial result row does not match. All partial results must come "
+          + "from the same row. partialResultsRow: " + Bytes.toString(partialResultsRow) + "row: "
+          + Bytes.toString(row));
+    }
+    partialResultsRow = row;
+    partialResults.add(result);
+  }
+
+  /**
+   * Convenience method for clearing the list of partials and resetting the partialResultsRow.
+   */
+  private void clearPartialResults() {
+    partialResults.clear();
+    partialResultsRow = null;
+  }
+
+  /**
+   * Helper method for adding results between the indices [start, end) to the outputList
+   * @param outputList the list that results will be added to
+   * @param inputArray the array that results are taken from
+   * @param start beginning index (inclusive)
+   * @param end ending index (exclusive)
+   */
+  private void addResultsToList(List<Result> outputList, Result[] inputArray, int start, int end) {
+    if (inputArray == null || start < 0 || end > inputArray.length) return;
+
+    for (int i = start; i < end; i++) {
+      outputList.add(inputArray[i]);
+    }
+  }
+
     @Override
     public void close() {
       if (!scanMetricsPublished) writeScanMetrics();
@@ -476,4 +690,26 @@ public class ClientScanner extends AbstractClientScanner {
       }
       closed = true;
     }
+
+  /**
+   * Create the closest row before the specified row
+   * @param row
+   * @return a new byte array which is the closest front row of the specified one
+   */
+  protected static byte[] createClosestRowBefore(byte[] row) {
+    if (row == null) {
+      throw new IllegalArgumentException("The passed row is empty");
+    }
+    if (Bytes.equals(row, HConstants.EMPTY_BYTE_ARRAY)) {
+      return MAX_BYTE_ARRAY;
+    }
+    if (row[row.length - 1] == 0) {
+      return Arrays.copyOf(row, row.length - 1);
+    } else {
+      byte[] closestFrontRow = Arrays.copyOf(row, row.length);
+      closestFrontRow[row.length - 1] = (byte) ((closestFrontRow[row.length - 1] & 0xff) - 1);
+      closestFrontRow = Bytes.add(closestFrontRow, MAX_BYTE_ARRAY);
+      return closestFrontRow;
+    }
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClientSmallReversedScanner.java

@@ -31,9 +31,13 @@ import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.client.ClientSmallScanner.SmallScannerCallable;
+import org.apache.hadoop.hbase.client.ClientSmallScanner.SmallScannerCallableFactory;
 import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
 import org.apache.hadoop.hbase.util.Bytes;
 
+import com.google.common.annotations.VisibleForTesting;
+
 /**
  * Client scanner for small reversed scan. Generally, only one RPC is called to fetch the
  * scan results, unless the results cross multiple regions or the row count of
@@ -45,34 +49,83 @@ import org.apache.hadoop.hbase.util.Bytes;
 public class ClientSmallReversedScanner extends ReversedClientScanner {
   private static final Log LOG = LogFactory.getLog(ClientSmallReversedScanner.class);
   private ScannerCallableWithReplicas smallScanCallable = null;
-  private byte[] skipRowOfFirstResult = null;
+  private SmallScannerCallableFactory callableFactory;
 
   /**
-   * Create a new ReversibleClientScanner for the specified table Note that the
+   * Create a new ReversibleClientScanner for the specified table. Take note that the passed
-   * passed {@link Scan}'s start row maybe changed changed.
+   * {@link Scan} 's start row maybe changed changed.
    *
-   * @param conf The {@link Configuration} to use.
+   * @param conf
-   * @param scan {@link Scan} to use in this scanner
+   *          The {@link Configuration} to use.
-   * @param tableName The table that we wish to rangeGet
+   * @param scan
-   * @param connection Connection identifying the cluster
+   *          {@link Scan} to use in this scanner
+   * @param tableName
+   *          The table that we wish to rangeGet
+   * @param connection
+   *          Connection identifying the cluster
    * @param rpcFactory
+   *          Factory used to create the {@link RpcRetryingCaller}
+   * @param controllerFactory
+   *          Factory used to access RPC payloads
+   * @param pool
+   *          Threadpool for RPC threads
+   * @param primaryOperationTimeout
+   *          Call timeout
    * @throws IOException
+   *           If the remote call fails
    */
   public ClientSmallReversedScanner(final Configuration conf, final Scan scan,
-      final TableName tableName, ClusterConnection connection,
+      final TableName tableName, ClusterConnection connection, RpcRetryingCallerFactory rpcFactory,
-      RpcRetryingCallerFactory rpcFactory, RpcControllerFactory controllerFactory,
+      RpcControllerFactory controllerFactory, ExecutorService pool, int primaryOperationTimeout)
-      ExecutorService pool, int primaryOperationTimeout) throws IOException {
+      throws IOException {
-    super(conf, scan, tableName, connection, rpcFactory, controllerFactory, pool,
+    this(conf, scan, tableName, connection, rpcFactory, controllerFactory, pool,
-        primaryOperationTimeout);
+        primaryOperationTimeout, new SmallScannerCallableFactory());
   }
 
   /**
-   * Gets a scanner for following scan. Move to next region or continue from the
+   * Create a new ReversibleClientScanner for the specified table. Take note that the passed
-   * last result or start from the start row.
+   * {@link Scan}'s start row may be changed.
+   *
+   * @param conf
+   *          The {@link Configuration} to use.
+   * @param scan
+   *          {@link Scan} to use in this scanner
+   * @param tableName
+   *          The table that we wish to rangeGet
+   * @param connection
+   *          Connection identifying the cluster
+   * @param rpcFactory
+   *          Factory used to create the {@link RpcRetryingCaller}
+   * @param controllerFactory
+   *          Factory used to access RPC payloads
+   * @param pool
+   *          Threadpool for RPC threads
+   * @param primaryOperationTimeout
+   *          Call timeout
+   * @param callableFactory
+   *          Factory used to create the {@link SmallScannerCallable}
+   * @throws IOException
+   *           If the remote call fails
+   */
+  @VisibleForTesting
+  ClientSmallReversedScanner(final Configuration conf, final Scan scan, final TableName tableName,
+      ClusterConnection connection, RpcRetryingCallerFactory rpcFactory,
+      RpcControllerFactory controllerFactory, ExecutorService pool, int primaryOperationTimeout,
+      SmallScannerCallableFactory callableFactory) throws IOException {
+    super(conf, scan, tableName, connection, rpcFactory, controllerFactory, pool,
+        primaryOperationTimeout);
+    this.callableFactory = callableFactory;
+  }
+
+  /**
+   * Gets a scanner for following scan. Move to next region or continue from the last result or
+   * start from the start row.
    *
    * @param nbRows
-   * @param done              true if Server-side says we're done scanning.
+   * @param done
-   * @param currentRegionDone true if scan is over on current region
+   *          true if Server-side says we're done scanning.
+   * @param currentRegionDone
+   *          true if scan is over on current region
    * @return true if has next scanner
    * @throws IOException
    */
@@ -81,7 +134,7 @@ public class ClientSmallReversedScanner extends ReversedClientScanner {
     // Where to start the next getter
     byte[] localStartKey;
     int cacheNum = nbRows;
-    skipRowOfFirstResult = null;
+    boolean regionChanged = true;
     // if we're at end of table, close and return false to stop iterating
     if (this.currentRegion != null && currentRegionDone) {
       byte[] startKey = this.currentRegion.getStartKey();
@@ -100,9 +153,8 @@ public class ClientSmallReversedScanner extends ReversedClientScanner {
         LOG.debug("Finished with region " + this.currentRegion);
       }
     } else if (this.lastResult != null) {
-      localStartKey = this.lastResult.getRow();
+      regionChanged = false;
-      skipRowOfFirstResult = this.lastResult.getRow();
+      localStartKey = createClosestRowBefore(lastResult.getRow());
-      cacheNum++;
     } else {
       localStartKey = this.scan.getStartRow();
     }
@@ -112,12 +164,11 @@ public class ClientSmallReversedScanner extends ReversedClientScanner {
           + Bytes.toStringBinary(localStartKey) + "'");
     }
 
-    smallScanCallable = ClientSmallScanner.getSmallScanCallable(
+    smallScanCallable = callableFactory.getCallable(getConnection(), getTable(), scan,
-      getConnection(), getTable(), scan, getScanMetrics(), localStartKey, cacheNum,
+        getScanMetrics(), localStartKey, cacheNum, rpcControllerFactory, getPool(),
-      rpcControllerFactory, getPool(), getPrimaryOperationTimeout(),
+        getPrimaryOperationTimeout(), getRetries(), getScannerTimeout(), getConf(), caller);
-      getRetries(), getScannerTimeout(), getConf(), caller);
 
-    if (this.scanMetrics != null && skipRowOfFirstResult == null) {
+    if (this.scanMetrics != null && regionChanged) {
       this.scanMetrics.countOfRegions.incrementAndGet();
     }
     return true;
@@ -131,45 +182,7 @@ public class ClientSmallReversedScanner extends ReversedClientScanner {
       return null;
     }
     if (cache.size() == 0) {
-      Result[] values = null;
+      loadCache();
-      long remainingResultSize = maxScannerResultSize;
-      int countdown = this.caching;
-      boolean currentRegionDone = false;
-      // Values == null means server-side filter has determined we must STOP
-      while (remainingResultSize > 0 && countdown > 0
-          && nextScanner(countdown, values == null, currentRegionDone)) {
-        // Server returns a null values if scanning is to stop. Else,
-        // returns an empty array if scanning is to go on and we've just
-        // exhausted current region.
-        // callWithoutRetries is at this layer. Within the ScannerCallableWithReplicas,
-        // we do a callWithRetries
-        values = this.caller.callWithoutRetries(smallScanCallable, scannerTimeout);
-        this.currentRegion = smallScanCallable.getHRegionInfo();
-        long currentTime = System.currentTimeMillis();
-        if (this.scanMetrics != null) {
-          this.scanMetrics.sumOfMillisSecBetweenNexts.addAndGet(currentTime
-              - lastNext);
-        }
-        lastNext = currentTime;
-        if (values != null && values.length > 0) {
-          for (int i = 0; i < values.length; i++) {
-            Result rs = values[i];
-            if (i == 0 && this.skipRowOfFirstResult != null
-                && Bytes.equals(skipRowOfFirstResult, rs.getRow())) {
-              // Skip the first result
-              continue;
-            }
-            cache.add(rs);
-            // We don't make Iterator here
-            for (Cell cell : rs.rawCells()) {
-              remainingResultSize -= CellUtil.estimatedHeapSizeOf(cell);
-            }
-            countdown--;
-            this.lastResult = rs;
-          }
-        }
-        currentRegionDone = countdown > 0;
-      }
     }
 
     if (cache.size() > 0) {
@@ -181,6 +194,47 @@ public class ClientSmallReversedScanner extends ReversedClientScanner {
     return null;
   }
 
+  @Override
+  protected void loadCache() throws IOException {
+    Result[] values = null;
+    long remainingResultSize = maxScannerResultSize;
+    int countdown = this.caching;
+    boolean currentRegionDone = false;
+    // Values == null means server-side filter has determined we must STOP
+    while (remainingResultSize > 0 && countdown > 0
+        && nextScanner(countdown, values == null, currentRegionDone)) {
+      // Server returns a null values if scanning is to stop. Else,
+      // returns an empty array if scanning is to go on and we've just
+      // exhausted current region.
+      // callWithoutRetries is at this layer. Within the ScannerCallableWithReplicas,
+      // we do a callWithRetries
+      values = this.caller.callWithoutRetries(smallScanCallable, scannerTimeout);
+      this.currentRegion = smallScanCallable.getHRegionInfo();
+      long currentTime = System.currentTimeMillis();
+      if (this.scanMetrics != null) {
+        this.scanMetrics.sumOfMillisSecBetweenNexts.addAndGet(currentTime
+            - lastNext);
+      }
+      lastNext = currentTime;
+      if (values != null && values.length > 0) {
+        for (int i = 0; i < values.length; i++) {
+          Result rs = values[i];
+          cache.add(rs);
+          // We don't make Iterator here
+          for (Cell cell : rs.rawCells()) {
+            remainingResultSize -= CellUtil.estimatedHeapSizeOf(cell);
+          }
+          countdown--;
+          this.lastResult = rs;
+        }
+      }
+      if (smallScanCallable.hasMoreResultsContext()) {
+        currentRegionDone = !smallScanCallable.getServerHasMoreResults();
+      } else {
+        currentRegionDone = countdown > 0;
+      }
+    }
+  }
 
   @Override
   protected void initializeScannerInConstruction() throws IOException {
@@ -194,4 +248,8 @@ public class ClientSmallReversedScanner extends ReversedClientScanner {
     closed = true;
   }
 
+  @VisibleForTesting
+  protected void setScannerCallableFactory(SmallScannerCallableFactory callableFactory) {
+    this.callableFactory = callableFactory;
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClientSmallScanner.java

@@ -39,6 +39,7 @@ import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ScanRequest;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ScanResponse;
 import org.apache.hadoop.hbase.util.Bytes;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.protobuf.ServiceException;
 
 /**
@@ -52,29 +53,72 @@ import com.google.protobuf.ServiceException;
 public class ClientSmallScanner extends ClientScanner {
   private final Log LOG = LogFactory.getLog(this.getClass());
   private ScannerCallableWithReplicas smallScanCallable = null;
-  // When fetching results from server, skip the first result if it has the same
+  private SmallScannerCallableFactory callableFactory;
-  // row with this one
-  private byte[] skipRowOfFirstResult = null;
 
   /**
-   * Create a new ShortClientScanner for the specified table Note that the
+   * Create a new ShortClientScanner for the specified table. Take note that the passed {@link Scan}
-   * passed {@link Scan}'s start row maybe changed changed.
+   * 's start row maybe changed changed.
    *
-   * @param conf The {@link Configuration} to use.
+   * @param conf
-   * @param scan {@link Scan} to use in this scanner
+   *          The {@link Configuration} to use.
-   * @param tableName The table that we wish to rangeGet
+   * @param scan
-   * @param connection Connection identifying the cluster
+   *          {@link Scan} to use in this scanner
+   * @param tableName
+   *          The table that we wish to rangeGet
+   * @param connection
+   *          Connection identifying the cluster
    * @param rpcFactory
+   *          Factory used to create the {@link RpcRetryingCaller}
+   * @param controllerFactory
+   *          Factory used to access RPC payloads
    * @param pool
+   *          Threadpool for RPC threads
    * @param primaryOperationTimeout
+   *          Call timeout
+   * @throws IOException
+   *           If the remote call fails
+   */
+  public ClientSmallScanner(final Configuration conf, final Scan scan, final TableName tableName,
+      ClusterConnection connection, RpcRetryingCallerFactory rpcFactory,
+      RpcControllerFactory controllerFactory, ExecutorService pool, int primaryOperationTimeout)
+      throws IOException {
+    this(conf, scan, tableName, connection, rpcFactory, controllerFactory, pool,
+        primaryOperationTimeout, new SmallScannerCallableFactory());
+  }
+
+  /**
+   * Create a new ShortClientScanner for the specified table. Take note that the passed {@link Scan}
+   * 's start row maybe changed changed. Intended for unit tests to provide their own
+   * {@link SmallScannerCallableFactory} implementation/mock.
+   *
+   * @param conf
+   *          The {@link Configuration} to use.
+   * @param scan
+   *          {@link Scan} to use in this scanner
+   * @param tableName
+   *          The table that we wish to rangeGet
+   * @param connection
+   *          Connection identifying the cluster
+   * @param rpcFactory
+   *          Factory used to create the {@link RpcRetryingCaller}
+   * @param controllerFactory
+   *          Factory used to access RPC payloads
+   * @param pool
+   *          Threadpool for RPC threads
+   * @param primaryOperationTimeout
+   *          Call timeout
+   * @param callableFactory
+   *          Factory used to create the {@link SmallScannerCallable}
    * @throws IOException
    */
-  public ClientSmallScanner(final Configuration conf, final Scan scan,
+  @VisibleForTesting
-      final TableName tableName, ClusterConnection connection,
+  ClientSmallScanner(final Configuration conf, final Scan scan, final TableName tableName,
-      RpcRetryingCallerFactory rpcFactory, RpcControllerFactory controllerFactory,
+      ClusterConnection connection, RpcRetryingCallerFactory rpcFactory,
-      ExecutorService pool, int primaryOperationTimeout) throws IOException {
+      RpcControllerFactory controllerFactory, ExecutorService pool, int primaryOperationTimeout,
+      SmallScannerCallableFactory callableFactory) throws IOException {
     super(conf, scan, tableName, connection, rpcFactory, controllerFactory, pool,
-           primaryOperationTimeout);
+        primaryOperationTimeout);
+    this.callableFactory = callableFactory;
   }
 
   @Override
@@ -97,26 +141,25 @@ public class ClientSmallScanner extends ClientScanner {
     // Where to start the next getter
     byte[] localStartKey;
     int cacheNum = nbRows;
-    skipRowOfFirstResult = null;
+    boolean regionChanged = true;
     // if we're at end of table, close and return false to stop iterating
     if (this.currentRegion != null && currentRegionDone) {
       byte[] endKey = this.currentRegion.getEndKey();
       if (endKey == null || Bytes.equals(endKey, HConstants.EMPTY_BYTE_ARRAY)
           || checkScanStopRow(endKey) || done) {
         close();
-        if (LOG.isDebugEnabled()) {
+        if (LOG.isTraceEnabled()) {
-          LOG.debug("Finished with small scan at " + this.currentRegion);
+          LOG.trace("Finished with small scan at " + this.currentRegion);
         }
         return false;
       }
       localStartKey = endKey;
-      if (LOG.isDebugEnabled()) {
+      if (LOG.isTraceEnabled()) {
-        LOG.debug("Finished with region " + this.currentRegion);
+        LOG.trace("Finished with region " + this.currentRegion);
       }
     } else if (this.lastResult != null) {
-      localStartKey = this.lastResult.getRow();
+      regionChanged = false;
-      skipRowOfFirstResult = this.lastResult.getRow();
+      localStartKey = Bytes.add(lastResult.getRow(), new byte[1]);
-      cacheNum++;
     } else {
       localStartKey = this.scan.getStartRow();
     }
@@ -125,32 +168,15 @@ public class ClientSmallScanner extends ClientScanner {
       LOG.trace("Advancing internal small scanner to startKey at '"
           + Bytes.toStringBinary(localStartKey) + "'");
     }
-    smallScanCallable = getSmallScanCallable(
+    smallScanCallable = callableFactory.getCallable(getConnection(), getTable(), scan,
-        getConnection(), getTable(), scan, getScanMetrics(), localStartKey, cacheNum,
+        getScanMetrics(), localStartKey, cacheNum, rpcControllerFactory, getPool(),
-        rpcControllerFactory, getPool(), getPrimaryOperationTimeout(),
+        getPrimaryOperationTimeout(), getRetries(), getScannerTimeout(), getConf(), caller);
-        getRetries(), getScannerTimeout(), getConf(), caller);
+    if (this.scanMetrics != null && regionChanged) {
-    if (this.scanMetrics != null && skipRowOfFirstResult == null) {
       this.scanMetrics.countOfRegions.incrementAndGet();
     }
     return true;
   }
 
-
-  static ScannerCallableWithReplicas getSmallScanCallable(
-      ClusterConnection connection, TableName table, Scan scan,
-      ScanMetrics scanMetrics,  byte[] localStartKey, final int cacheNum,
-      RpcControllerFactory controllerFactory, ExecutorService pool, int primaryOperationTimeout,
-      int retries, int scannerTimeout, Configuration conf, RpcRetryingCaller<Result []> caller) {
-    scan.setStartRow(localStartKey);
-    SmallScannerCallable s = new SmallScannerCallable(
-      connection, table, scan, scanMetrics, controllerFactory, cacheNum, 0);
-    ScannerCallableWithReplicas scannerCallableWithReplicas =
-        new ScannerCallableWithReplicas(table, connection,
-            s, pool, primaryOperationTimeout, scan, retries,
-            scannerTimeout, cacheNum, conf, caller);
-    return scannerCallableWithReplicas;
-  }
-
   static class SmallScannerCallable extends ScannerCallable {
     public SmallScannerCallable(
         ClusterConnection connection, TableName table, Scan scan,
@@ -173,8 +199,15 @@ public class ClientSmallScanner extends ClientScanner {
         controller.setPriority(getTableName());
         controller.setCallTimeout(timeout);
         response = getStub().scan(controller, request);
-        return ResponseConverter.getResults(controller.cellScanner(),
+        Result[] results = ResponseConverter.getResults(controller.cellScanner(),
             response);
+        if (response.hasMoreResultsInRegion()) {
+          setHasMoreResultsContext(true);
+          setServerHasMoreResults(response.getMoreResultsInRegion());
+        } else {
+          setHasMoreResultsContext(false);
+        }
+        return results;
       } catch (ServiceException se) {
         throw ProtobufUtil.getRemoteException(se);
       }
@@ -195,45 +228,7 @@ public class ClientSmallScanner extends ClientScanner {
       return null;
     }
     if (cache.size() == 0) {
-      Result[] values = null;
+      loadCache();
-      long remainingResultSize = maxScannerResultSize;
-      int countdown = this.caching;
-      boolean currentRegionDone = false;
-      // Values == null means server-side filter has determined we must STOP
-      while (remainingResultSize > 0 && countdown > 0
-          && nextScanner(countdown, values == null, currentRegionDone)) {
-        // Server returns a null values if scanning is to stop. Else,
-        // returns an empty array if scanning is to go on and we've just
-        // exhausted current region.
-        // callWithoutRetries is at this layer. Within the ScannerCallableWithReplicas,
-        // we do a callWithRetries
-        values = this.caller.callWithoutRetries(smallScanCallable, scannerTimeout);
-        this.currentRegion = smallScanCallable.getHRegionInfo();
-        long currentTime = System.currentTimeMillis();
-        if (this.scanMetrics != null) {
-          this.scanMetrics.sumOfMillisSecBetweenNexts.addAndGet(currentTime
-              - lastNext);
-        }
-        lastNext = currentTime;
-        if (values != null && values.length > 0) {
-          for (int i = 0; i < values.length; i++) {
-            Result rs = values[i];
-            if (i == 0 && this.skipRowOfFirstResult != null
-                && Bytes.equals(skipRowOfFirstResult, rs.getRow())) {
-              // Skip the first result
-              continue;
-            }
-            cache.add(rs);
-            // We don't make Iterator here
-            for (Cell cell : rs.rawCells()) {
-              remainingResultSize -= CellUtil.estimatedHeapSizeOf(cell);
-            }
-            countdown--;
-            this.lastResult = rs;
-          }
-        }
-        currentRegionDone = countdown > 0;
-      }
     }
 
     if (cache.size() > 0) {
@@ -246,8 +241,75 @@ public class ClientSmallScanner extends ClientScanner {
   }
 
   @Override
+  protected void loadCache() throws IOException {
+    Result[] values = null;
+    long remainingResultSize = maxScannerResultSize;
+    int countdown = this.caching;
+    boolean currentRegionDone = false;
+    // Values == null means server-side filter has determined we must STOP
+    while (remainingResultSize > 0 && countdown > 0
+        && nextScanner(countdown, values == null, currentRegionDone)) {
+      // Server returns a null values if scanning is to stop. Else,
+      // returns an empty array if scanning is to go on and we've just
+      // exhausted current region.
+      // callWithoutRetries is at this layer. Within the ScannerCallableWithReplicas,
+      // we do a callWithRetries
+      values = this.caller.callWithoutRetries(smallScanCallable, scannerTimeout);
+      this.currentRegion = smallScanCallable.getHRegionInfo();
+      long currentTime = System.currentTimeMillis();
+      if (this.scanMetrics != null) {
+        this.scanMetrics.sumOfMillisSecBetweenNexts.addAndGet(currentTime
+            - lastNext);
+      }
+      lastNext = currentTime;
+      if (values != null && values.length > 0) {
+        for (int i = 0; i < values.length; i++) {
+          Result rs = values[i];
+          cache.add(rs);
+          // We don't make Iterator here
+          for (Cell cell : rs.rawCells()) {
+            remainingResultSize -= CellUtil.estimatedHeapSizeOf(cell);
+          }
+          countdown--;
+          this.lastResult = rs;
+        }
+      }
+      if (smallScanCallable.hasMoreResultsContext()) {
+        // If the server has more results, the current region is not done
+        currentRegionDone = !smallScanCallable.getServerHasMoreResults();
+      } else {
+        // not guaranteed to get the context in older versions, fall back to checking countdown
+        currentRegionDone = countdown > 0;
+      }
+    }
+  }
+
   public void close() {
     if (!scanMetricsPublished) writeScanMetrics();
     closed = true;
   }
+
+  @VisibleForTesting
+  protected void setScannerCallableFactory(SmallScannerCallableFactory callableFactory) {
+    this.callableFactory = callableFactory;
+  }
+
+  @InterfaceAudience.Private
+  protected static class SmallScannerCallableFactory {
+
+    public ScannerCallableWithReplicas getCallable(ClusterConnection connection, TableName table,
+        Scan scan, ScanMetrics scanMetrics, byte[] localStartKey, int cacheNum,
+        RpcControllerFactory controllerFactory, ExecutorService pool, int primaryOperationTimeout,
+        int retries, int scannerTimeout, Configuration conf, RpcRetryingCaller<Result[]> caller) {
+      scan.setStartRow(localStartKey);
+      SmallScannerCallable s = new SmallScannerCallable(
+        connection, table, scan, scanMetrics, controllerFactory, cacheNum, 0);
+      ScannerCallableWithReplicas scannerCallableWithReplicas =
+          new ScannerCallableWithReplicas(table, connection,
+              s, pool, primaryOperationTimeout, scan, retries,
+              scannerTimeout, cacheNum, conf, caller);
+      return scannerCallableWithReplicas;
+    }
+
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterConnection.java

@@ -287,12 +287,6 @@ public interface ClusterConnection extends HConnection {
    */
   RpcRetryingCallerFactory getNewRpcRetryingCallerFactory(Configuration conf);
   
-  /**
-   * 
-   * @return true if this is a managed connection.
-   */
-  boolean isManaged();
-
   /**
    * @return the current statistics tracker associated with this connection
    */
@@ -302,4 +296,4 @@ public interface ClusterConnection extends HConnection {
    * @return the configured client backoff policy
    */
   ClientBackoffPolicy getBackoffPolicy();
-}
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Connection.java

@@ -74,10 +74,13 @@ public interface Connection extends Abortable, Closeable {
    * The returned Table is not thread safe, a new instance should be created for each using thread.
    * This is a lightweight operation, pooling or caching of the returned Table
    * is neither required nor desired.
-   * <br>
+   * <p>
    * The caller is responsible for calling {@link Table#close()} on the returned
    * table instance.
-   *
+   * <p>
+   * Since 0.98.1 this method no longer checks table existence. An exception
+   * will be thrown if the table does not exist only when the first operation is
+   * attempted.
    * @param tableName the name of the table
    * @return a Table to use for interactions with this table
    */
@@ -88,9 +91,13 @@ public interface Connection extends Abortable, Closeable {
    * The returned Table is not thread safe, a new instance should be created for each using thread.
    * This is a lightweight operation, pooling or caching of the returned Table
    * is neither required nor desired.
-   * <br>
+   * <p>
    * The caller is responsible for calling {@link Table#close()} on the returned
    * table instance.
+   * <p>
+   * Since 0.98.1 this method no longer checks table existence. An exception
+   * will be thrown if the table does not exist only when the first operation is
+   * attempted.
    *
    * @param tableName the name of the table
    * @param pool The thread pool to use for batch operations, null to use a default pool.

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionAdapter.java

@@ -41,7 +41,7 @@ import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.MasterService;
  * A convenience to override when customizing method implementations.
  *
  *
- * @see ConnectionUtils#createShortCircuitHConnection(HConnection, ServerName,
+ * @see ConnectionUtils#createShortCircuitHConnection(Connection, ServerName,
  * AdminService.BlockingInterface, ClientService.BlockingInterface) for case where we make
  * Connections skip RPC if request is to local server.
  */
@@ -455,11 +455,6 @@ abstract class ConnectionAdapter implements ClusterConnection {
     return wrappedConnection.getNewRpcRetryingCallerFactory(conf);
   }
   
-  @Override
-  public boolean isManaged() {
-    return wrappedConnection.isManaged();
-  }
-
   @Override
   public ServerStatisticTracker getStatisticsTracker() {
     return wrappedConnection.getStatisticsTracker();

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionFactory.java

@@ -50,7 +50,6 @@ import org.apache.hadoop.hbase.security.UserProvider;
  * Similarly, {@link Connection} also returns {@link Admin} and {@link RegionLocator}
  * implementations.
  *
- * This class replaces {@link HConnectionManager}, which is now deprecated.
  * @see Connection
  * @since 0.99.0
  */
@@ -215,15 +214,9 @@ public class ConnectionFactory {
       user = provider.getCurrent();
     }
 
-    return createConnection(conf, false, pool, user);
-  }
-
-  static Connection createConnection(final Configuration conf, final boolean managed,
-      final ExecutorService pool, final User user)
-  throws IOException {
     String className = conf.get(HConnection.HBASE_CLIENT_CONNECTION_IMPL,
-      ConnectionManager.HConnectionImplementation.class.getName());
+      ConnectionImplementation.class.getName());
-    Class<?> clazz = null;
+    Class<?> clazz;
     try {
       clazz = Class.forName(className);
     } catch (ClassNotFoundException e) {
@@ -233,9 +226,9 @@ public class ConnectionFactory {
       // Default HCM#HCI is not accessible; make it so before invoking.
       Constructor<?> constructor =
         clazz.getDeclaredConstructor(Configuration.class,
-          boolean.class, ExecutorService.class, User.class);
+          ExecutorService.class, User.class);
       constructor.setAccessible(true);
-      return (Connection) constructor.newInstance(conf, managed, pool, user);
+      return (Connection) constructor.newInstance(conf, pool, user);
     } catch (Exception e) {
       throw new IOException(e);
     }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionUtils.java

@@ -82,7 +82,7 @@ public final class ConnectionUtils {
    */
   public static NonceGenerator injectNonceGeneratorForTesting(
       ClusterConnection conn, NonceGenerator cnm) {
-    return ConnectionManager.injectNonceGeneratorForTesting(conn, cnm);
+    return ConnectionImplementation.injectNonceGeneratorForTesting(conn, cnm);
   }
 
   /**
@@ -94,6 +94,7 @@ public final class ConnectionUtils {
    */
   public static void setServerSideHConnectionRetriesConfig(
       final Configuration c, final String sn, final Log log) {
+    // TODO: Fix this. Not all connections from server side should have 10 times the retries.
     int hcRetries = c.getInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER,
       HConstants.DEFAULT_HBASE_CLIENT_RETRIES_NUMBER);
     // Go big.  Multiply by 10.  If we can't get to meta after this many retries
@@ -145,10 +146,10 @@ public final class ConnectionUtils {
    * Some tests shut down the master. But table availability is a master RPC which is performed on
    * region re-lookups.
    */
-  static class MasterlessConnection extends ConnectionManager.HConnectionImplementation {
+  static class MasterlessConnection extends ConnectionImplementation {
-    MasterlessConnection(Configuration conf, boolean managed,
+    MasterlessConnection(Configuration conf,
       ExecutorService pool, User user) throws IOException {
-      super(conf, managed, pool, user);
+      super(conf, pool, user);
     }
 
     @Override

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Delete.java

@@ -253,7 +253,9 @@ public class Delete extends Mutation implements Comparable<Row> {
    * @param family family name
    * @param timestamp version timestamp
    * @return this for invocation chaining
+   * @deprecated Since hbase-1.0.0. Use {@link #addFamilyVersion(byte[], long)}
    */
+  @Deprecated
   public Delete deleteFamilyVersion(byte [] family, long timestamp) {
     return addFamilyVersion(family, timestamp);
   }
@@ -264,9 +266,7 @@ public class Delete extends Mutation implements Comparable<Row> {
    * @param family family name
    * @param timestamp version timestamp
    * @return this for invocation chaining
-   * @deprecated Since hbase-1.0.0. Use {@link #addFamilyVersion(byte[], long)}
    */
-  @Deprecated
   public Delete addFamilyVersion(final byte [] family, final long timestamp) {
     List<Cell> list = familyMap.get(family);
     if(list == null) {

hbase-client/src/main/java/org/apache/hadoop/hbase/client/FlushRegionCallable.java

@@ -0,0 +1,102 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.hbase.client;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.ipc.PayloadCarryingRpcController;
+import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
+import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
+import org.apache.hadoop.hbase.protobuf.RequestConverter;
+import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.FlushRegionRequest;
+import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.FlushRegionResponse;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+import org.mortbay.log.Log;
+
+import com.google.protobuf.ServiceException;
+
+/**
+ * A Callable for flushRegion() RPC.
+ */
+@InterfaceAudience.Private
+public class FlushRegionCallable extends RegionAdminServiceCallable<FlushRegionResponse> {
+
+  private final byte[] regionName;
+  private final boolean writeFlushWalMarker;
+  private boolean reload;
+
+  public FlushRegionCallable(ClusterConnection connection,
+      RpcControllerFactory rpcControllerFactory, TableName tableName, byte[] regionName,
+      byte[] regionStartKey, boolean writeFlushWalMarker) {
+    super(connection, rpcControllerFactory, tableName, regionStartKey);
+    this.regionName = regionName;
+    this.writeFlushWalMarker = writeFlushWalMarker;
+  }
+
+  public FlushRegionCallable(ClusterConnection connection,
+      RpcControllerFactory rpcControllerFactory, HRegionInfo regionInfo,
+      boolean writeFlushWalMarker) {
+    this(connection, rpcControllerFactory, regionInfo.getTable(), regionInfo.getRegionName(),
+      regionInfo.getStartKey(), writeFlushWalMarker);
+  }
+
+  @Override
+  public FlushRegionResponse call(int callTimeout) throws Exception {
+    return flushRegion();
+  }
+
+  @Override
+  public void prepare(boolean reload) throws IOException {
+    super.prepare(reload);
+    this.reload = reload;
+  }
+
+  private FlushRegionResponse flushRegion() throws IOException {
+    // check whether we should still do the flush to this region. If the regions are changed due
+    // to splits or merges, etc return success
+    if (!Bytes.equals(location.getRegionInfo().getRegionName(), regionName)) {
+      if (!reload) {
+        throw new IOException("Cached location seems to be different than requested region.");
+      }
+      Log.info("Skipping flush region, because the located region "
+          + Bytes.toStringBinary(location.getRegionInfo().getRegionName()) + " is different than "
+          + " requested region " + Bytes.toStringBinary(regionName));
+      return FlushRegionResponse.newBuilder()
+          .setLastFlushTime(EnvironmentEdgeManager.currentTime())
+          .setFlushed(false)
+          .setWroteFlushWalMarker(false)
+          .build();
+    }
+
+    FlushRegionRequest request =
+        RequestConverter.buildFlushRegionRequest(regionName, writeFlushWalMarker);
+
+    try {
+      PayloadCarryingRpcController controller = rpcControllerFactory.newController();
+      controller.setPriority(tableName);
+      return stub.flushRegion(controller, request);
+    } catch (ServiceException se) {
+      throw ProtobufUtil.getRemoteException(se);
+    }
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Get.java

@@ -98,6 +98,7 @@ public class Get extends Query
    * @param get
    */
   public Get(Get get) {
+    this(get.getRow());
     this.filter = get.getFilter();
     this.cacheBlocks = get.getCacheBlocks();
     this.maxVersions = get.getMaxVersions();

hbase-client/src/main/java/org/apache/hadoop/hbase/client/HConnection.java

@@ -38,22 +38,16 @@ import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.MasterService;
 /**
  * A cluster connection.  Knows how to find the master, locate regions out on the cluster,
  * keeps a cache of locations and then knows how to re-calibrate after they move.  You need one
- * of these to talk to your HBase cluster. {@link HConnectionManager} manages instances of this
+ * of these to talk to your HBase cluster. {@link ConnectionFactory} manages instances of this
  * class.  See it for how to get one of these.
  *
  * <p>This is NOT a connection to a particular server but to ALL servers in the cluster.  Individual
  * connections are managed at a lower level.
  *
  * <p>HConnections are used by {@link HTable} mostly but also by
- * {@link HBaseAdmin}, and {@link org.apache.hadoop.hbase.zookeeper.MetaTableLocator}.
+ * {@link HBaseAdmin}, and {@link org.apache.hadoop.hbase.zookeeper.MetaTableLocator}. 
- * HConnection instances can be shared.  Sharing
- * is usually what you want because rather than each HConnection instance
- * having to do its own discovery of regions out on the cluster, instead, all
- * clients get to share the one cache of locations.  {@link HConnectionManager} does the
- * sharing for you if you go by it getting connections.  Sharing makes cleanup of
- * HConnections awkward.  See {@link HConnectionManager} for cleanup discussion.
  *
- * @see HConnectionManager
+ * @see ConnectionFactory
  * @deprecated in favor of {@link Connection} and {@link ConnectionFactory}
  */
 @InterfaceAudience.Public
@@ -78,8 +72,7 @@ public interface HConnection extends Connection {
    * be created for each using thread.
    * This is a lightweight operation, pooling or caching of the returned HTableInterface
    * is neither required nor desired.
-   * Note that the HConnection needs to be unmanaged
+   * (created with {@link ConnectionFactory#createConnection(Configuration)}).
-   * (created with {@link HConnectionManager#createConnection(Configuration)}).
    * @param tableName
    * @return an HTable to use for interactions with this table
    */
@@ -91,8 +84,7 @@ public interface HConnection extends Connection {
    * be created for each using thread.
    * This is a lightweight operation, pooling or caching of the returned HTableInterface
    * is neither required nor desired.
-   * Note that the HConnection needs to be unmanaged
+   * (created with {@link ConnectionFactory#createConnection(Configuration)}).
-   * (created with {@link HConnectionManager#createConnection(Configuration)}).
    * @param tableName
    * @return an HTable to use for interactions with this table
    */
@@ -104,8 +96,7 @@ public interface HConnection extends Connection {
    * be created for each using thread.
    * This is a lightweight operation, pooling or caching of the returned HTableInterface
    * is neither required nor desired.
-   * Note that the HConnection needs to be unmanaged
+   * (created with {@link ConnectionFactory#createConnection(Configuration)}).
-   * (created with {@link HConnectionManager#createConnection(Configuration)}).
    * @param tableName
    * @return an HTable to use for interactions with this table
    */
@@ -118,8 +109,7 @@ public interface HConnection extends Connection {
    * be created for each using thread.
    * This is a lightweight operation, pooling or caching of the returned HTableInterface
    * is neither required nor desired.
-   * Note that the HConnection needs to be unmanaged
+   * (created with {@link ConnectionFactory#createConnection(Configuration)}).
-   * (created with {@link HConnectionManager#createConnection(Configuration)}).
    * @param tableName
    * @param pool The thread pool to use for batch operations, null to use a default pool.
    * @return an HTable to use for interactions with this table
@@ -132,8 +122,7 @@ public interface HConnection extends Connection {
    * be created for each using thread.
    * This is a lightweight operation, pooling or caching of the returned HTableInterface
    * is neither required nor desired.
-   * Note that the HConnection needs to be unmanaged
+   * (created with {@link ConnectionFactory#createConnection(Configuration)}).
-   * (created with {@link HConnectionManager#createConnection(Configuration)}).
    * @param tableName
    * @param pool The thread pool to use for batch operations, null to use a default pool.
    * @return an HTable to use for interactions with this table
@@ -146,9 +135,8 @@ public interface HConnection extends Connection {
    * be created for each using thread.
    * This is a lightweight operation, pooling or caching of the returned HTableInterface
    * is neither required nor desired.
-   * Note that the HConnection needs to be unmanaged
+   * (created with {@link ConnectionFactory#createConnection(Configuration)}).
-   * (created with {@link HConnectionManager#createConnection(Configuration)}).
+   * @param tableName table to get interface for
-   * @param tableName
    * @param pool The thread pool to use for batch operations, null to use a default pool.
    * @return an HTable to use for interactions with this table
    */
@@ -161,10 +149,6 @@ public interface HConnection extends Connection {
    *
    * This is a lightweight operation.  Pooling or caching of the returned RegionLocator is neither
    * required nor desired.
-   *
-   * RegionLocator needs to be unmanaged
-   * (created with {@link HConnectionManager#createConnection(Configuration)}).
-   *
    * @param tableName Name of the table who's region is to be examined
    * @return A RegionLocator instance
    */
@@ -175,7 +159,7 @@ public interface HConnection extends Connection {
    * Retrieve an Admin implementation to administer an HBase cluster.
    * The returned Admin is not guaranteed to be thread-safe.  A new instance should be created for
    * each using thread.  This is a lightweight operation.  Pooling or caching of the returned
-   * Admin is not recommended.  Note that HConnection needs to be unmanaged
+   * Admin is not recommended.
    *
    * @return an Admin instance for cluster administration
    */

hbase-client/src/main/java/org/apache/hadoop/hbase/client/HConnectionKey.java

@@ -1,146 +0,0 @@
-/**
- * Copyright The Apache Software Foundation
- *
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.hadoop.hbase.client;
-
-import java.io.IOException;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.HConstants;
-import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
-import org.apache.hadoop.hbase.security.User;
-import org.apache.hadoop.hbase.security.UserProvider;
-
-/**
- * Denotes a unique key to an {@link HConnection} instance.
- *
- * In essence, this class captures the properties in {@link Configuration}
- * that may be used in the process of establishing a connection. In light of
- * that, if any new such properties are introduced into the mix, they must be
- * added to the {@link HConnectionKey#properties} list.
- *
- */
-class HConnectionKey {
-  final static String[] CONNECTION_PROPERTIES = new String[] {
-      HConstants.ZOOKEEPER_QUORUM, HConstants.ZOOKEEPER_ZNODE_PARENT,
-      HConstants.ZOOKEEPER_CLIENT_PORT,
-      HConstants.ZOOKEEPER_RECOVERABLE_WAITTIME,
-      HConstants.HBASE_CLIENT_PAUSE, HConstants.HBASE_CLIENT_RETRIES_NUMBER,
-      HConstants.HBASE_RPC_TIMEOUT_KEY,
-      HConstants.HBASE_META_SCANNER_CACHING,
-      HConstants.HBASE_CLIENT_INSTANCE_ID,
-      HConstants.RPC_CODEC_CONF_KEY,
-      HConstants.USE_META_REPLICAS,
-      RpcControllerFactory.CUSTOM_CONTROLLER_CONF_KEY};
-
-  private Map<String, String> properties;
-  private String username;
-
-  HConnectionKey(Configuration conf) {
-    Map<String, String> m = new HashMap<String, String>();
-    if (conf != null) {
-      for (String property : CONNECTION_PROPERTIES) {
-        String value = conf.get(property);
-        if (value != null) {
-          m.put(property, value);
-        }
-      }
-    }
-    this.properties = Collections.unmodifiableMap(m);
-
-    try {
-      UserProvider provider = UserProvider.instantiate(conf);
-      User currentUser = provider.getCurrent();
-      if (currentUser != null) {
-        username = currentUser.getName();
-      }
-    } catch (IOException ioe) {
-      ConnectionManager.LOG.warn(
-          "Error obtaining current user, skipping username in HConnectionKey", ioe);
-    }
-  }
-
-  @Override
-  public int hashCode() {
-    final int prime = 31;
-    int result = 1;
-    if (username != null) {
-      result = username.hashCode();
-    }
-    for (String property : CONNECTION_PROPERTIES) {
-      String value = properties.get(property);
-      if (value != null) {
-        result = prime * result + value.hashCode();
-      }
-    }
-
-    return result;
-  }
-
-
-  @edu.umd.cs.findbugs.annotations.SuppressWarnings (value="ES_COMPARING_STRINGS_WITH_EQ",
-      justification="Optimization")
-  @Override
-  public boolean equals(Object obj) {
-    if (this == obj)
-      return true;
-    if (obj == null)
-      return false;
-    if (getClass() != obj.getClass())
-      return false;
-    HConnectionKey that = (HConnectionKey) obj;
-    if (this.username != null && !this.username.equals(that.username)) {
-      return false;
-    } else if (this.username == null && that.username != null) {
-      return false;
-    }
-    if (this.properties == null) {
-      if (that.properties != null) {
-        return false;
-      }
-    } else {
-      if (that.properties == null) {
-        return false;
-      }
-      for (String property : CONNECTION_PROPERTIES) {
-        String thisValue = this.properties.get(property);
-        String thatValue = that.properties.get(property);
-        //noinspection StringEquality
-        if (thisValue == thatValue) {
-          continue;
-        }
-        if (thisValue == null || !thisValue.equals(thatValue)) {
-          return false;
-        }
-      }
-    }
-    return true;
-  }
-
-  @Override
-  public String toString() {
-    return "HConnectionKey{" +
-      "properties=" + properties +
-      ", username='" + username + '\'' +
-      '}';
-  }
-}

hbase-client/src/main/java/org/apache/hadoop/hbase/client/HConnectionManager.java

@@ -1,324 +0,0 @@
-/**
- *
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.hadoop.hbase.client;
-
-import java.io.IOException;
-import java.util.concurrent.ExecutorService;
-
-import org.apache.commons.logging.Log;
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.classification.InterfaceAudience;
-import org.apache.hadoop.hbase.classification.InterfaceStability;
-import org.apache.hadoop.hbase.security.User;
-
-/**
- * A non-instantiable class that manages creation of {@link HConnection}s.
- * <p>The simplest way to use this class is by using {@link #createConnection(Configuration)}.
- * This creates a new {@link HConnection} to the cluster that is managed by the caller.
- * From this {@link HConnection} {@link HTableInterface} implementations are retrieved
- * with {@link HConnection#getTable(byte[])}. Example:
- * <pre>
- * HConnection connection = HConnectionManager.createConnection(config);
- * HTableInterface table = connection.getTable(TableName.valueOf("table1"));
- * try {
- *   // Use the table as needed, for a single operation and a single thread
- * } finally {
- *   table.close();
- *   connection.close();
- * }
- * </pre>
- * <p>This class has a static Map of {@link HConnection} instances keyed by
- * {@link HConnectionKey}; A {@link HConnectionKey} is identified by a set of
- * {@link Configuration} properties. Invocations of {@link #getConnection(Configuration)}
- * that pass the same {@link Configuration} instance will return the same
- * {@link  HConnection} instance ONLY WHEN the set of properties are the same
- * (i.e. if you change properties in your {@link Configuration} instance, such as RPC timeout,
- * the codec used, HBase will create a new {@link HConnection} instance. For more details on
- * how this is done see {@link HConnectionKey}).
- * <p>Sharing {@link HConnection} instances is usually what you want; all clients
- * of the {@link HConnection} instances share the HConnections' cache of Region
- * locations rather than each having to discover for itself the location of meta, etc.
- * But sharing connections makes clean up of {@link HConnection} instances a little awkward.
- * Currently, clients cleanup by calling {@link #deleteConnection(Configuration)}. This will
- * shutdown the zookeeper connection the HConnection was using and clean up all
- * HConnection resources as well as stopping proxies to servers out on the
- * cluster. Not running the cleanup will not end the world; it'll
- * just stall the closeup some and spew some zookeeper connection failed
- * messages into the log.  Running the cleanup on a {@link HConnection} that is
- * subsequently used by another will cause breakage so be careful running
- * cleanup.
- * <p>To create a {@link HConnection} that is not shared by others, you can
- * set property "hbase.client.instance.id" to a unique value for your {@link Configuration}
- * instance, like the following:
- * <pre>
- * {@code
- * conf.set("hbase.client.instance.id", "12345");
- * HConnection connection = HConnectionManager.getConnection(conf);
- * // Use the connection to your hearts' delight and then when done...
- * conf.set("hbase.client.instance.id", "12345");
- * HConnectionManager.deleteConnection(conf, true);
- * }
- * </pre>
- * <p>Cleanup used to be done inside in a shutdown hook.  On startup we'd
- * register a shutdown hook that called {@link #deleteAllConnections()}
- * on its way out but the order in which shutdown hooks run is not defined so
- * were problematic for clients of HConnection that wanted to register their
- * own shutdown hooks so we removed ours though this shifts the onus for
- * cleanup to the client.
- * @deprecated Please use ConnectionFactory instead
- */
-@InterfaceAudience.Public
-@InterfaceStability.Evolving
-@Deprecated
-public final class HConnectionManager extends ConnectionFactory {
-
-  /** @deprecated connection caching is going away */
-  @Deprecated
-  public static final String RETRIES_BY_SERVER_KEY =
-      ConnectionManager.RETRIES_BY_SERVER_KEY;
-
-  /** @deprecated connection caching is going away */
-  @Deprecated
-  public static final int MAX_CACHED_CONNECTION_INSTANCES =
-      ConnectionManager.MAX_CACHED_CONNECTION_INSTANCES;
-
-  /*
-   * Non-instantiable.
-   */
-  private HConnectionManager() {
-    super();
-  }
-
-  /**
-   * Get the connection that goes with the passed <code>conf</code> configuration instance.
-   * If no current connection exists, method creates a new connection and keys it using
-   * connection-specific properties from the passed {@link Configuration}; see
-   * {@link HConnectionKey}.
-   * @param conf configuration
-   * @return HConnection object for <code>conf</code>
-   * @deprecated connection caching is going away
-   */
-  @Deprecated
-  public static HConnection getConnection(final Configuration conf) throws IOException {
-    return ConnectionManager.getConnectionInternal(conf);
-  }
-
-  /**
-   * Create a new HConnection instance using the passed <code>conf</code> instance.
-   * <p>Note: This bypasses the usual HConnection life cycle management done by
-   * {@link #getConnection(Configuration)}. The caller is responsible for
-   * calling {@link HConnection#close()} on the returned connection instance.
-   *
-   * This is the recommended way to create HConnections.
-   * <pre>
-   * HConnection connection = HConnectionManager.createConnection(conf);
-   * HTableInterface table = connection.getTable("mytable");
-   * try {
-   *   table.get(...);
-   *   ...
-   * } finally {
-   *   table.close();
-   *   connection.close();
-   * }
-   * </pre>
-   *
-   * @param conf configuration
-   * @return HConnection object for <code>conf</code>
-   * @deprecated in favor of {@link Connection} and {@link ConnectionFactory}
-   */
-  @Deprecated
-  public static HConnection createConnection(Configuration conf) throws IOException {
-    return ConnectionManager.createConnectionInternal(conf);
-  }
-
-
-  /**
-   * Create a new HConnection instance using the passed <code>conf</code> instance.
-   * <p>Note: This bypasses the usual HConnection life cycle management done by
-   * {@link #getConnection(Configuration)}. The caller is responsible for
-   * calling {@link HConnection#close()} on the returned connection instance.
-   * This is the recommended way to create HConnections.
-   * <pre>
-   * ExecutorService pool = ...;
-   * HConnection connection = HConnectionManager.createConnection(conf, pool);
-   * HTableInterface table = connection.getTable("mytable");
-   * table.get(...);
-   * ...
-   * table.close();
-   * connection.close();
-   * </pre>
-   * @param conf configuration
-   * @param pool the thread pool to use for batch operation in HTables used via this HConnection
-   * @return HConnection object for <code>conf</code>
-   * @deprecated in favor of {@link Connection} and {@link ConnectionFactory}
-   */
-  @Deprecated
-  public static HConnection createConnection(Configuration conf, ExecutorService pool)
-      throws IOException {
-    return ConnectionManager.createConnection(conf, pool);
-  }
-
-  /**
-   * Create a new HConnection instance using the passed <code>conf</code> instance.
-   * <p>Note: This bypasses the usual HConnection life cycle management done by
-   * {@link #getConnection(Configuration)}. The caller is responsible for
-   * calling {@link HConnection#close()} on the returned connection instance.
-   * This is the recommended way to create HConnections.
-   * <pre>
-   * ExecutorService pool = ...;
-   * HConnection connection = HConnectionManager.createConnection(conf, pool);
-   * HTableInterface table = connection.getTable("mytable");
-   * table.get(...);
-   * ...
-   * table.close();
-   * connection.close();
-   * </pre>
-   * @param conf configuration
-   * @param user the user the connection is for
-   * @return HConnection object for <code>conf</code>
-   * @deprecated in favor of {@link Connection} and {@link ConnectionFactory}
-   */
-  @Deprecated
-  public static HConnection createConnection(Configuration conf, User user)
-  throws IOException {
-    return ConnectionManager.createConnection(conf, user);
-  }
-
-  /**
-   * Create a new HConnection instance using the passed <code>conf</code> instance.
-   * <p>Note: This bypasses the usual HConnection life cycle management done by
-   * {@link #getConnection(Configuration)}. The caller is responsible for
-   * calling {@link HConnection#close()} on the returned connection instance.
-   * This is the recommended way to create HConnections.
-   * <pre>
-   * ExecutorService pool = ...;
-   * HConnection connection = HConnectionManager.createConnection(conf, pool);
-   * HTableInterface table = connection.getTable("mytable");
-   * table.get(...);
-   * ...
-   * table.close();
-   * connection.close();
-   * </pre>
-   * @param conf configuration
-   * @param pool the thread pool to use for batch operation in HTables used via this HConnection
-   * @param user the user the connection is for
-   * @return HConnection object for <code>conf</code>
-   * @deprecated in favor of {@link Connection} and {@link ConnectionFactory}
-   */
-  @Deprecated
-  public static HConnection createConnection(Configuration conf, ExecutorService pool, User user)
-  throws IOException {
-    return ConnectionManager.createConnection(conf, pool, user);
-  }
-
-  /**
-   * @deprecated in favor of {@link Connection} and {@link ConnectionFactory}
-   */
-  @Deprecated
-  static HConnection createConnection(final Configuration conf, final boolean managed)
-      throws IOException {
-    return ConnectionManager.createConnection(conf, managed);
-  }
-
-  /**
-   * @deprecated in favor of {@link Connection} and {@link ConnectionFactory}
-   */
-  @Deprecated
-  static ClusterConnection createConnection(final Configuration conf, final boolean managed,
-      final ExecutorService pool, final User user) throws IOException {
-    return ConnectionManager.createConnection(conf, managed, pool, user);
-  }
-
-  /**
-   * Delete connection information for the instance specified by passed configuration.
-   * If there are no more references to the designated connection connection, this method will
-   * then close connection to the zookeeper ensemble and let go of all associated resources.
-   *
-   * @param conf configuration whose identity is used to find {@link HConnection} instance.
-   * @deprecated connection caching is going away.
-   */
-  @Deprecated
-  public static void deleteConnection(Configuration conf) {
-    ConnectionManager.deleteConnection(conf);
-  }
-
-  /**
-   * Cleanup a known stale connection.
-   * This will then close connection to the zookeeper ensemble and let go of all resources.
-   *
-   * @param connection
-   * @deprecated connection caching is going away.
-   */
-  @Deprecated
-  public static void deleteStaleConnection(HConnection connection) {
-    ConnectionManager.deleteStaleConnection(connection);
-  }
-
-  /**
-   * Delete information for all connections. Close or not the connection, depending on the
-   *  staleConnection boolean and the ref count. By default, you should use it with
-   *  staleConnection to true.
-   * @deprecated connection caching is going away.
-   */
-  @Deprecated
-  public static void deleteAllConnections(boolean staleConnection) {
-    ConnectionManager.deleteAllConnections(staleConnection);
-  }
-
-  /**
-   * Delete information for all connections..
-   * @deprecated kept for backward compatibility, but the behavior is broken. HBASE-8983
-   */
-  @Deprecated
-  public static void deleteAllConnections() {
-    ConnectionManager.deleteAllConnections();
-  }
-
-  /**
-   * This convenience method invokes the given {@link HConnectable#connect}
-   * implementation using a {@link HConnection} instance that lasts just for the
-   * duration of the invocation.
-   *
-   * @param <T> the return type of the connect method
-   * @param connectable the {@link HConnectable} instance
-   * @return the value returned by the connect method
-   * @throws IOException
-   * @deprecated Internal method, do not use thru HConnectionManager.
-   */
-  @InterfaceAudience.Private
-  @Deprecated
-  public static <T> T execute(HConnectable<T> connectable) throws IOException {
-    return ConnectionManager.execute(connectable);
-  }
-
-  /**
-   * Set the number of retries to use serverside when trying to communicate
-   * with another server over {@link HConnection}.  Used updating catalog
-   * tables, etc.  Call this method before we create any Connections.
-   * @param c The Configuration instance to set the retries into.
-   * @param log Used to log what we set in here.
-   * @deprecated Internal method, do not use.
-   */
-  @InterfaceAudience.Private
-  @Deprecated
-  public static void setServerSideHConnectionRetries(
-      final Configuration c, final String sn, final Log log) {
-    ConnectionUtils.setServerSideHConnectionRetriesConfig(c, sn, log);
-  }
-}

hbase-client/src/main/java/org/apache/hadoop/hbase/client/HRegionLocator.java

@@ -21,12 +21,12 @@ package org.apache.hadoop.hbase.client;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.NavigableMap;
-import java.util.Map.Entry;
 
+import com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.HRegionLocation;
+import org.apache.hadoop.hbase.MetaTableAccessor;
 import org.apache.hadoop.hbase.RegionLocations;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
@@ -34,8 +34,6 @@ import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.util.Pair;
 
-import com.google.common.annotations.VisibleForTesting;
-
 /**
  * An implementation of {@link RegionLocator}. Used to view region location information for a single
  * HBase table. Lightweight. Get as needed and just close when done. Instances of this class SHOULD
@@ -85,11 +83,11 @@ public class HRegionLocator implements RegionLocator {
 
   @Override
   public List<HRegionLocation> getAllRegionLocations() throws IOException {
-    NavigableMap<HRegionInfo, ServerName> locations =
+    List<Pair<HRegionInfo, ServerName>> locations =
-        MetaScanner.allTableRegions(this.connection, getName());
+        MetaTableAccessor.getTableRegionsAndLocations(this.connection, getName());
     ArrayList<HRegionLocation> regions = new ArrayList<>(locations.size());
-    for (Entry<HRegionInfo, ServerName> entry : locations.entrySet()) {
+    for (Pair<HRegionInfo, ServerName> entry : locations) {
-      regions.add(new HRegionLocation(entry.getKey(), entry.getValue()));
+      regions.add(new HRegionLocation(entry.getFirst(), entry.getSecond()));
     }
     return regions;
   }
@@ -139,7 +137,18 @@ public class HRegionLocator implements RegionLocator {
 
   @VisibleForTesting
   List<RegionLocations> listRegionLocations() throws IOException {
-    return MetaScanner.listTableRegionLocations(getConfiguration(), this.connection, getName());
+    final List<RegionLocations> regions = new ArrayList<RegionLocations>();
+    MetaTableAccessor.Visitor visitor = new MetaTableAccessor.TableVisitorBase(tableName) {
+      @Override
+      public boolean visitInternal(Result result) throws IOException {
+        RegionLocations locations = MetaTableAccessor.getRegionLocations(result);
+        if (locations == null) return true;
+        regions.add(locations);
+        return true;
+      }
+    };
+    MetaTableAccessor.scanMetaForTableRegions(connection, visitor, tableName);
+    return regions;
   }
 
   public Configuration getConfiguration() {

hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java

@@ -44,6 +44,7 @@ import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.KeyValueUtil;
+import org.apache.hadoop.hbase.MetaTableAccessor;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.TableNotFoundException;
@@ -127,78 +128,6 @@ public class HTable implements HTableInterface {
   private RpcRetryingCallerFactory rpcCallerFactory;
   private RpcControllerFactory rpcControllerFactory;
 
-  /**
-   * Creates an object to access a HBase table.
-   * @param conf Configuration object to use.
-   * @param tableName Name of the table.
-   * @throws IOException if a remote or network exception occurs
-   * @deprecated Constructing HTable objects manually has been deprecated. Please use
-   * {@link Connection} to instantiate a {@link Table} instead.
-   */
-  @Deprecated
-  public HTable(Configuration conf, final String tableName)
-  throws IOException {
-    this(conf, TableName.valueOf(tableName));
-  }
-
-  /**
-   * Creates an object to access a HBase table.
-   * @param conf Configuration object to use.
-   * @param tableName Name of the table.
-   * @throws IOException if a remote or network exception occurs
-   * @deprecated Constructing HTable objects manually has been deprecated. Please use
-   * {@link Connection} to instantiate a {@link Table} instead.
-   */
-  @Deprecated
-  public HTable(Configuration conf, final byte[] tableName)
-  throws IOException {
-    this(conf, TableName.valueOf(tableName));
-  }
-
-  /**
-   * Creates an object to access a HBase table.
-   * @param conf Configuration object to use.
-   * @param tableName table name pojo
-   * @throws IOException if a remote or network exception occurs
-   * @deprecated Constructing HTable objects manually has been deprecated. Please use
-   * {@link Connection} to instantiate a {@link Table} instead.
-   */
-  @Deprecated
-  public HTable(Configuration conf, final TableName tableName)
-  throws IOException {
-    this.tableName = tableName;
-    this.cleanupPoolOnClose = true;
-    this.cleanupConnectionOnClose = true;
-    if (conf == null) {
-      this.connection = null;
-      return;
-    }
-    this.connection = (ClusterConnection) ConnectionFactory.createConnection(conf);
-    this.configuration = conf;
-
-    this.pool = getDefaultExecutor(conf);
-    this.finishSetup();
-  }
-
-  /**
-   * Creates an object to access a HBase table.
-   * @param tableName Name of the table.
-   * @param connection HConnection to be used.
-   * @throws IOException if a remote or network exception occurs
-   * @deprecated Do not use.
-   */
-  @Deprecated
-  public HTable(TableName tableName, Connection connection) throws IOException {
-    this.tableName = tableName;
-    this.cleanupPoolOnClose = true;
-    this.cleanupConnectionOnClose = false;
-    this.connection = (ClusterConnection)connection;
-    this.configuration = connection.getConfiguration();
-
-    this.pool = getDefaultExecutor(this.configuration);
-    this.finishSetup();
-  }
-
   // Marked Private @since 1.0
   @InterfaceAudience.Private
   public static ThreadPoolExecutor getDefaultExecutor(Configuration conf) {
@@ -218,68 +147,6 @@ public class HTable implements HTableInterface {
     return pool;
   }
 
-  /**
-   * Creates an object to access a HBase table.
-   * @param conf Configuration object to use.
-   * @param tableName Name of the table.
-   * @param pool ExecutorService to be used.
-   * @throws IOException if a remote or network exception occurs
-   * @deprecated Constructing HTable objects manually has been deprecated. Please use
-   * {@link Connection} to instantiate a {@link Table} instead.
-   */
-  @Deprecated
-  public HTable(Configuration conf, final byte[] tableName, final ExecutorService pool)
-      throws IOException {
-    this(conf, TableName.valueOf(tableName), pool);
-  }
-
-  /**
-   * Creates an object to access a HBase table.
-   * @param conf Configuration object to use.
-   * @param tableName Name of the table.
-   * @param pool ExecutorService to be used.
-   * @throws IOException if a remote or network exception occurs
-   * @deprecated Constructing HTable objects manually has been deprecated. Please use
-   * {@link Connection} to instantiate a {@link Table} instead.
-   */
-  @Deprecated
-  public HTable(Configuration conf, final TableName tableName, final ExecutorService pool)
-      throws IOException {
-    this.connection = (ClusterConnection) ConnectionFactory.createConnection(conf);
-    this.configuration = conf;
-    this.pool = pool;
-    if (pool == null) {
-      this.pool = getDefaultExecutor(conf);
-      this.cleanupPoolOnClose = true;
-    } else {
-      this.cleanupPoolOnClose = false;
-    }
-    this.tableName = tableName;
-    this.cleanupConnectionOnClose = true;
-    this.finishSetup();
-  }
-
-  /**
-   * Creates an object to access a HBase table.
-   * @param tableName Name of the table.
-   * @param connection HConnection to be used.
-   * @param pool ExecutorService to be used.
-   * @throws IOException if a remote or network exception occurs.
-   * @deprecated Do not use, internal ctor.
-   */
-  @Deprecated
-  public HTable(final byte[] tableName, final Connection connection,
-      final ExecutorService pool) throws IOException {
-    this(TableName.valueOf(tableName), connection, pool);
-  }
-
-  /** @deprecated Do not use, internal ctor. */
-  @Deprecated
-  public HTable(TableName tableName, final Connection connection,
-      final ExecutorService pool) throws IOException {
-    this(tableName, (ClusterConnection)connection, null, null, null, pool);
-  }
-
   /**
    * Creates an object to access a HBase table.
    * Used by HBase internally.  DO NOT USE. See {@link ConnectionFactory} class comment for how to
@@ -290,7 +157,7 @@ public class HTable implements HTableInterface {
    * @throws IOException if a remote or network exception occurs
    */
   @InterfaceAudience.Private
-  public HTable(TableName tableName, final ClusterConnection connection,
+  protected HTable(TableName tableName, final ClusterConnection connection,
       final TableConfiguration tableConfig,
       final RpcRetryingCallerFactory rpcCallerFactory,
       final RpcControllerFactory rpcControllerFactory,
@@ -452,12 +319,9 @@ public class HTable implements HTableInterface {
   @Deprecated
   public static boolean isTableEnabled(Configuration conf,
       final TableName tableName) throws IOException {
-    return HConnectionManager.execute(new HConnectable<Boolean>(conf) {
+    try(Connection conn = ConnectionFactory.createConnection(conf)) {
-      @Override
+      return conn.getAdmin().isTableEnabled(tableName);
-      public Boolean connect(HConnection connection) throws IOException {
+    }
-        return connection.isTableEnabled(tableName);
-      }
-    });
   }
 
   /**
@@ -517,17 +381,6 @@ public class HTable implements HTableInterface {
     return this.connection;
   }
 
-  /**
-   * Gets the number of rows that a scanner will fetch at once.
-   * <p>
-   * The default value comes from {@code hbase.client.scanner.caching}.
-   * @deprecated Use {@link Scan#setCaching(int)} and {@link Scan#getCaching()}
-   */
-  @Deprecated
-  public int getScannerCaching() {
-    return scannerCaching;
-  }
-
   /**
    * Kept in 0.96 for backward compatibility
    * @deprecated  since 0.96. This is an internal buffer that should not be read nor write.
@@ -537,22 +390,6 @@ public class HTable implements HTableInterface {
     return mutator == null ? null : mutator.getWriteBuffer();
   }
 
-  /**
-   * Sets the number of rows that a scanner will fetch at once.
-   * <p>
-   * This will override the value specified by
-   * {@code hbase.client.scanner.caching}.
-   * Increasing this value will reduce the amount of work needed each time
-   * {@code next()} is called on a scanner, at the expense of memory use
-   * (since more rows will need to be maintained in memory by the scanners).
-   * @param scannerCaching the number of rows a scanner will fetch at once.
-   * @deprecated Use {@link Scan#setCaching(int)}
-   */
-  @Deprecated
-  public void setScannerCaching(int scannerCaching) {
-    this.scannerCaching = scannerCaching;
-  }
-
   /**
    * {@inheritDoc}
    */
@@ -625,11 +462,12 @@ public class HTable implements HTableInterface {
    * @throws IOException if a remote or network exception occurs
    * @deprecated This is no longer a public API.  Use {@link #getAllRegionLocations()} instead.
    */
+  @SuppressWarnings("deprecation")
   @Deprecated
   public NavigableMap<HRegionInfo, ServerName> getRegionLocations() throws IOException {
     // TODO: Odd that this returns a Map of HRI to SN whereas getRegionLocator, singular,
     // returns an HRegionLocation.
-    return MetaScanner.allTableRegions(this.connection, getName());
+    return MetaTableAccessor.allTableRegions(this.connection, getName());
   }
 
   /**
@@ -775,7 +613,7 @@ public class HTable implements HTableInterface {
       throw new IllegalArgumentException("Small scan should not be used with batching");
     }
     if (scan.getCaching() <= 0) {
-      scan.setCaching(getScannerCaching());
+      scan.setCaching(scannerCaching);
     }
 
     if (scan.isReversed()) {
@@ -1038,7 +876,15 @@ public class HTable implements HTableInterface {
           regionMutationBuilder.setAtomic(true);
           MultiRequest request =
             MultiRequest.newBuilder().addRegionAction(regionMutationBuilder.build()).build();
-          getStub().multi(controller, request);
+          ClientProtos.MultiResponse response = getStub().multi(controller, request);
+          ClientProtos.RegionActionResult res = response.getRegionActionResultList().get(0);
+          if (res.hasException()) {
+            Throwable ex = ProtobufUtil.toException(res.getException());
+            if(ex instanceof IOException) {
+              throw (IOException)ex;
+            }
+            throw new IOException("Failed to mutate row: "+Bytes.toStringBinary(rm.getRow()), ex);
+          }
         } catch (ServiceException se) {
           throw ProtobufUtil.getRemoteException(se);
         }
@@ -1317,6 +1163,15 @@ public class HTable implements HTableInterface {
                   getLocation().getRegionInfo().getRegionName(), row, family, qualifier,
                   new BinaryComparator(value), compareType, rm);
               ClientProtos.MultiResponse response = getStub().multi(controller, request);
+              ClientProtos.RegionActionResult res = response.getRegionActionResultList().get(0);
+              if (res.hasException()) {
+                Throwable ex = ProtobufUtil.toException(res.getException());
+                if(ex instanceof IOException) {
+                  throw (IOException)ex;
+                }
+                throw new IOException("Failed to checkAndMutate row: "+
+                    Bytes.toStringBinary(rm.getRow()), ex);
+              }
               return Boolean.valueOf(response.getProcessed());
             } catch (ServiceException se) {
               throw ProtobufUtil.getRemoteException(se);
@@ -1438,6 +1293,7 @@ public class HTable implements HTableInterface {
           terminated = this.pool.awaitTermination(60, TimeUnit.SECONDS);
         } while (!terminated);
       } catch (InterruptedException e) {
+        this.pool.shutdownNow();
         LOG.warn("waitForTermination interrupted");
       }
     }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Increment.java

@@ -53,6 +53,8 @@ import org.apache.hadoop.hbase.util.ClassSize;
 public class Increment extends Mutation implements Comparable<Row> {
   private static final long HEAP_OVERHEAD =  ClassSize.REFERENCE + ClassSize.TIMERANGE;
 
+  private static final String RETURN_RESULTS = "_rr_";
+
   private TimeRange tr = new TimeRange();
 
   /**
@@ -161,6 +163,24 @@ public class Increment extends Mutation implements Comparable<Row> {
     tr = new TimeRange(minStamp, maxStamp);
     return this;
   }
+  
+  /**
+   * @param returnResults True (default) if the increment operation should return the results. A
+   *          client that is not interested in the result can save network bandwidth setting this
+   *          to false.
+   */
+  public Increment setReturnResults(boolean returnResults) {
+    setAttribute(RETURN_RESULTS, Bytes.toBytes(returnResults));
+    return this;
+  }
+
+  /**
+   * @return current value for returnResults
+   */
+  public boolean isReturnResults() {
+    byte[] v = getAttribute(RETURN_RESULTS);
+    return v == null ? true : Bytes.toBoolean(v);
+  }
 
   /**
    * Method for retrieving the number of families to increment from

hbase-client/src/main/java/org/apache/hadoop/hbase/client/MetaScanner.java

@@ -1,425 +0,0 @@
-/**
- *
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.hadoop.hbase.client;
-
-import java.io.Closeable;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.NavigableMap;
-import java.util.TreeMap;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.HConstants;
-import org.apache.hadoop.hbase.HRegionInfo;
-import org.apache.hadoop.hbase.HRegionLocation;
-import org.apache.hadoop.hbase.MetaTableAccessor;
-import org.apache.hadoop.hbase.RegionLocations;
-import org.apache.hadoop.hbase.ServerName;
-import org.apache.hadoop.hbase.TableName;
-import org.apache.hadoop.hbase.TableNotFoundException;
-import org.apache.hadoop.hbase.classification.InterfaceAudience;
-import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.hbase.util.ExceptionUtil;
-
-import com.google.common.annotations.VisibleForTesting;
-
-/**
- * Scanner class that contains the <code>hbase:meta</code> table scanning logic.
- * Provided visitors will be called for each row.
- *
- * Although public visibility, this is not a public-facing API and may evolve in
- * minor releases.
- *
- * <p> Note that during concurrent region splits, the scanner might not see
- * hbase:meta changes across rows (for parent and daughter entries) consistently.
- * see HBASE-5986, and {@link DefaultMetaScannerVisitor} for details. </p>
- */
-@InterfaceAudience.Private
-//TODO: merge this to MetaTableAccessor, get rid of it.
-public final class MetaScanner {
-  private static final Log LOG = LogFactory.getLog(MetaScanner.class);
-
-  private MetaScanner() {}
-
-  /**
-   * Scans the meta table and calls a visitor on each RowResult and uses a empty
-   * start row value as table name.
-   * 
-   * <p>Visible for testing. Use {@link
-   * #metaScan(Connection, MetaScannerVisitor, TableName)} instead.
-   *
-   * @param visitor A custom visitor
-   * @throws IOException e
-   */
-  @VisibleForTesting // Do not use. Used by tests only and hbck.
-  public static void metaScan(Connection connection,
-      MetaScannerVisitor visitor) throws IOException {
-    metaScan(connection, visitor, null, null, Integer.MAX_VALUE);
-  }
-
-  /**
-   * Scans the meta table and calls a visitor on each RowResult. Uses a table
-   * name to locate meta regions.
-   *
-   * @param connection connection to use internally (null to use a new instance)
-   * @param visitor visitor object
-   * @param userTableName User table name in meta table to start scan at.  Pass
-   * null if not interested in a particular table.
-   * @throws IOException e
-   */
-  public static void metaScan(Connection connection,
-      MetaScannerVisitor visitor, TableName userTableName) throws IOException {
-    metaScan(connection, visitor, userTableName, null, Integer.MAX_VALUE,
-        TableName.META_TABLE_NAME);
-  }
-
-  /**
-   * Scans the meta table and calls a visitor on each RowResult. Uses a table
-   * name and a row name to locate meta regions. And it only scans at most
-   * <code>rowLimit</code> of rows.
-   * 
-   * <p>Visible for testing. Use {@link
-   * #metaScan(Connection, MetaScannerVisitor, TableName)} instead.
-   *
-   * @param connection to scan on
-   * @param visitor Visitor object.
-   * @param userTableName User table name in meta table to start scan at.  Pass
-   * null if not interested in a particular table.
-   * @param row Name of the row at the user table. The scan will start from
-   * the region row where the row resides.
-   * @param rowLimit Max of processed rows. If it is less than 0, it
-   * will be set to default value <code>Integer.MAX_VALUE</code>.
-   * @throws IOException e
-   */
-  @VisibleForTesting // Do not use. Used by Master but by a method that is used testing.
-  public static void metaScan(Connection connection,
-      MetaScannerVisitor visitor, TableName userTableName, byte[] row,
-      int rowLimit)
-  throws IOException {
-    metaScan(connection, visitor, userTableName, row, rowLimit, TableName
-        .META_TABLE_NAME);
-  }
-
-  /**
-   * Scans the meta table and calls a visitor on each RowResult. Uses a table
-   * name and a row name to locate meta regions. And it only scans at most
-   * <code>rowLimit</code> of rows.
-   *
-   * @param connection connection to use internally (null to use a new instance)
-   * @param visitor Visitor object. Closes the visitor before returning.
-   * @param tableName User table name in meta table to start scan at.  Pass
-   * null if not interested in a particular table.
-   * @param row Name of the row at the user table. The scan will start from
-   * the region row where the row resides.
-   * @param rowLimit Max of processed rows. If it is less than 0, it
-   * will be set to default value <code>Integer.MAX_VALUE</code>.
-   * @param metaTableName Meta table to scan, root or meta.
-   * @throws IOException e
-   */
-  static void metaScan(Connection connection,
-      final MetaScannerVisitor visitor, final TableName tableName,
-      final byte[] row, final int rowLimit, final TableName metaTableName)
-    throws IOException {
-
-    int rowUpperLimit = rowLimit > 0 ? rowLimit: Integer.MAX_VALUE;
-    // Calculate startrow for scan.
-    byte[] startRow;
-    // If the passed in 'connection' is 'managed' -- i.e. every second test uses
-    // an HTable or an HBaseAdmin with managed connections -- then doing
-    // connection.getTable will throw an exception saying you are NOT to use
-    // managed connections getting tables.  Leaving this as it is for now. Will
-    // revisit when inclined to change all tests.  User code probaby makes use of
-    // managed connections too so don't change it till post hbase 1.0.
-    try (Table metaTable = new HTable(TableName.META_TABLE_NAME, connection, null)) {
-      if (row != null) {
-        // Scan starting at a particular row in a particular table
-        Result startRowResult = getClosestRowOrBefore(metaTable, tableName, row,
-            connection.getConfiguration().getBoolean(HConstants.USE_META_REPLICAS,
-                HConstants.DEFAULT_USE_META_REPLICAS));
-        if (startRowResult == null) {
-          throw new TableNotFoundException("Cannot find row in " + metaTable.getName() +
-            " for table: " + tableName + ", row=" + Bytes.toStringBinary(row));
-        }
-        HRegionInfo regionInfo = getHRegionInfo(startRowResult);
-        if (regionInfo == null) {
-          throw new IOException("HRegionInfo was null or empty in Meta for " +
-            tableName + ", row=" + Bytes.toStringBinary(row));
-        }
-        byte[] rowBefore = regionInfo.getStartKey();
-        startRow = HRegionInfo.createRegionName(tableName, rowBefore, HConstants.ZEROES, false);
-      } else if (tableName == null || tableName.getName().length == 0) {
-        // Full hbase:meta scan
-        startRow = HConstants.EMPTY_START_ROW;
-      } else {
-        // Scan hbase:meta for an entire table
-        startRow = HRegionInfo.createRegionName(tableName, HConstants.EMPTY_START_ROW,
-          HConstants.ZEROES, false);
-      }
-      final Scan scan = new Scan(startRow).addFamily(HConstants.CATALOG_FAMILY);
-      int scannerCaching = connection.getConfiguration()
-          .getInt(HConstants.HBASE_META_SCANNER_CACHING,
-              HConstants.DEFAULT_HBASE_META_SCANNER_CACHING);
-      if (connection.getConfiguration().getBoolean(HConstants.USE_META_REPLICAS,
-                HConstants.DEFAULT_USE_META_REPLICAS)) {
-        scan.setConsistency(Consistency.TIMELINE);
-      }
-      if (rowUpperLimit <= scannerCaching) {
-          scan.setSmall(true);
-      }
-      int rows = Math.min(rowLimit, scannerCaching);
-      scan.setCaching(rows);
-      if (LOG.isTraceEnabled()) {
-        LOG.trace("Scanning " + metaTableName.getNameAsString() + " starting at row=" +
-          Bytes.toStringBinary(startRow) + " for max=" + rowUpperLimit + " with caching=" + rows);
-      }
-      // Run the scan
-      try (ResultScanner resultScanner = metaTable.getScanner(scan)) {
-        Result result;
-        int processedRows = 0;
-        while ((result = resultScanner.next()) != null) {
-          if (visitor != null) {
-            if (!visitor.processRow(result)) break;
-          }
-          processedRows++;
-          if (processedRows >= rowUpperLimit) break;
-        }
-      }
-    } finally {
-      if (visitor != null) {
-        try {
-          visitor.close();
-        } catch (Throwable t) {
-          ExceptionUtil.rethrowIfInterrupt(t);
-          LOG.debug("Got exception in closing the meta scanner visitor", t);
-        }
-      }
-    }
-  }
-
-  /**
-   * @return Get closest metatable region row to passed <code>row</code>
-   * @throws IOException
-   */
-  private static Result getClosestRowOrBefore(final Table metaTable, final TableName userTableName,
-      final byte [] row, boolean useMetaReplicas)
-  throws IOException {
-    byte[] searchRow = HRegionInfo.createRegionName(userTableName, row, HConstants.NINES, false);
-    Scan scan = Scan.createGetClosestRowOrBeforeReverseScan(searchRow);
-    if (useMetaReplicas) {
-      scan.setConsistency(Consistency.TIMELINE);
-    }
-    try (ResultScanner resultScanner = metaTable.getScanner(scan)) {
-      return resultScanner.next();
-    }
-  }
-
-  /**
-   * Returns HRegionInfo object from the column
-   * HConstants.CATALOG_FAMILY:HConstants.REGIONINFO_QUALIFIER of the catalog
-   * table Result.
-   * @param data a Result object from the catalog table scan
-   * @return HRegionInfo or null
-   * @deprecated Use {@link org.apache.hadoop.hbase.MetaTableAccessor#getRegionLocations(Result)}
-   */
-  @Deprecated
-  public static HRegionInfo getHRegionInfo(Result data) {
-    return HRegionInfo.getHRegionInfo(data);
-  }
-
-  /**
-   * Lists all of the regions currently in META.
-   * @param conf configuration
-   * @param connection to connect with
-   * @param offlined True if we are to include offlined regions, false and we'll
-   * leave out offlined regions from returned list.
-   * @return List of all user-space regions.
-   * @throws IOException
-   */
-  @VisibleForTesting // And for hbck.
-  public static List<HRegionInfo> listAllRegions(Configuration conf, Connection connection,
-      final boolean offlined)
-  throws IOException {
-    final List<HRegionInfo> regions = new ArrayList<HRegionInfo>();
-    MetaScannerVisitor visitor = new MetaScannerVisitorBase() {
-        @Override
-        public boolean processRow(Result result) throws IOException {
-          if (result == null || result.isEmpty()) {
-            return true;
-          }
-
-          RegionLocations locations = MetaTableAccessor.getRegionLocations(result);
-          if (locations == null) return true;
-          for (HRegionLocation loc : locations.getRegionLocations()) {
-            if (loc != null) {
-              HRegionInfo regionInfo = loc.getRegionInfo();
-              // If region offline AND we are not to include offlined regions, return.
-              if (regionInfo.isOffline() && !offlined) continue;
-              regions.add(regionInfo);
-            }
-          }
-          return true;
-        }
-    };
-    metaScan(connection, visitor);
-    return regions;
-  }
-
-  /**
-   * Lists all of the table regions currently in META.
-   * @param conf
-   * @param offlined True if we are to include offlined regions, false and we'll
-   * leave out offlined regions from returned list.
-   * @return Map of all user-space regions to servers
-   * @throws IOException
-   * @deprecated Use {@link #allTableRegions(Connection, TableName)} instead
-   */
-  @Deprecated
-  public static NavigableMap<HRegionInfo, ServerName> allTableRegions(Configuration conf,
-      Connection connection, final TableName tableName, boolean offlined) throws IOException {
-    return allTableRegions(connection, tableName);
-  }
-
-  /**
-   * Lists all of the table regions currently in META.
-   * @param connection
-   * @param tableName
-   * @return Map of all user-space regions to servers
-   * @throws IOException
-   */
-  public static NavigableMap<HRegionInfo, ServerName> allTableRegions(
-      Connection connection, final TableName tableName) throws IOException {
-    final NavigableMap<HRegionInfo, ServerName> regions =
-      new TreeMap<HRegionInfo, ServerName>();
-    MetaScannerVisitor visitor = new TableMetaScannerVisitor(tableName) {
-      @Override
-      public boolean processRowInternal(Result result) throws IOException {
-        RegionLocations locations = MetaTableAccessor.getRegionLocations(result);
-        if (locations == null) return true;
-        for (HRegionLocation loc : locations.getRegionLocations()) {
-          if (loc != null) {
-            HRegionInfo regionInfo = loc.getRegionInfo();
-            regions.put(new UnmodifyableHRegionInfo(regionInfo), loc.getServerName());
-          }
-        }
-        return true;
-      }
-    };
-    metaScan(connection, visitor, tableName);
-    return regions;
-  }
-
-  /**
-   * Lists table regions and locations grouped by region range from META.
-   */
-  public static List<RegionLocations> listTableRegionLocations(Configuration conf,
-      Connection connection, final TableName tableName) throws IOException {
-    final List<RegionLocations> regions = new ArrayList<RegionLocations>();
-    MetaScannerVisitor visitor = new TableMetaScannerVisitor(tableName) {
-      @Override
-      public boolean processRowInternal(Result result) throws IOException {
-        RegionLocations locations = MetaTableAccessor.getRegionLocations(result);
-        if (locations == null) return true;
-        regions.add(locations);
-        return true;
-      }
-    };
-    metaScan(connection, visitor, tableName);
-    return regions;
-  }
-
-  /**
-   * Visitor class called to process each row of the hbase:meta table
-   */
-  public interface MetaScannerVisitor extends Closeable {
-    /**
-     * Visitor method that accepts a RowResult and the meta region location.
-     * Implementations can return false to stop the region's loop if it becomes
-     * unnecessary for some reason.
-     *
-     * @param rowResult result
-     * @return A boolean to know if it should continue to loop in the region
-     * @throws IOException e
-     */
-    boolean processRow(Result rowResult) throws IOException;
-  }
-
-  public static abstract class MetaScannerVisitorBase implements MetaScannerVisitor {
-    @Override
-    public void close() throws IOException {
-    }
-  }
-
-  /**
-   * A MetaScannerVisitor that skips offline regions and split parents
-   */
-  public static abstract class DefaultMetaScannerVisitor
-    extends MetaScannerVisitorBase {
-
-    public DefaultMetaScannerVisitor() {
-      super();
-    }
-
-    public abstract boolean processRowInternal(Result rowResult) throws IOException;
-
-    @Override
-    public boolean processRow(Result rowResult) throws IOException {
-      HRegionInfo info = getHRegionInfo(rowResult);
-      if (info == null) {
-        return true;
-      }
-
-      //skip over offline and split regions
-      if (!(info.isOffline() || info.isSplit())) {
-        return processRowInternal(rowResult);
-      }
-      return true;
-    }
-  }
-
-  /**
-   * A MetaScannerVisitor for a table. Provides a consistent view of the table's
-   * hbase:meta entries during concurrent splits (see HBASE-5986 for details). This class
-   * does not guarantee ordered traversal of meta entries, and can block until the
-   * hbase:meta entries for daughters are available during splits.
-   */
-  public static abstract class TableMetaScannerVisitor extends DefaultMetaScannerVisitor {
-    private TableName tableName;
-
-    public TableMetaScannerVisitor(TableName tableName) {
-      super();
-      this.tableName = tableName;
-    }
-
-    @Override
-    public final boolean processRow(Result rowResult) throws IOException {
-      HRegionInfo info = getHRegionInfo(rowResult);
-      if (info == null) {
-        return true;
-      }
-      if (!(info.getTable().equals(tableName))) {
-        return false;
-      }
-      return super.processRow(rowResult);
-    }
-  }
-}

hbase-client/src/main/java/org/apache/hadoop/hbase/client/MultiAction.java

@@ -31,7 +31,7 @@ import org.apache.hadoop.hbase.util.Bytes;
 
 /**
  * Container for Actions (i.e. Get, Delete, or Put), which are grouped by
- * regionName. Intended to be used with HConnectionManager.processBatch()
+ * regionName. Intended to be used with {@link AsyncProcess}.
  */
 @InterfaceAudience.Private
 public final class MultiAction<R> {

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Put.java

@@ -137,9 +137,22 @@ public class Put extends Mutation implements HeapSize, Comparable<Row> {
    * @param qualifier column qualifier
    * @param value column value
    * @return this
+   * @deprecated Since 1.0.0. Use {@link #addColumn(byte[], byte[], byte[])}
    */
+  @Deprecated
   public Put add(byte [] family, byte [] qualifier, byte [] value) {
-    return add(family, qualifier, this.ts, value);
+    return addColumn(family, qualifier, value);
+  }
+
+  /**
+   * Add the specified column and value to this Put operation.
+   * @param family family name
+   * @param qualifier column qualifier
+   * @param value column value
+   * @return this
+   */
+  public Put addColumn(byte [] family, byte [] qualifier, byte [] value) {
+    return addColumn(family, qualifier, this.ts, value);
   }
 
   /**
@@ -167,8 +180,23 @@ public class Put extends Mutation implements HeapSize, Comparable<Row> {
    * @param ts version timestamp
    * @param value column value
    * @return this
+   * @deprecated Since 1.0.0. Use {@link #addColumn(byte[], byte[], long, byte[])}
    */
+  @Deprecated
   public Put add(byte [] family, byte [] qualifier, long ts, byte [] value) {
+    return addColumn(family, qualifier, ts, value);
+  }
+
+  /**
+   * Add the specified column and value, with the specified timestamp as
+   * its version to this Put operation.
+   * @param family family name
+   * @param qualifier column qualifier
+   * @param ts version timestamp
+   * @param value column value
+   * @return this
+   */
+  public Put addColumn(byte [] family, byte [] qualifier, long ts, byte [] value) {
     if (ts < 0) {
       throw new IllegalArgumentException("Timestamp cannot be negative. ts=" + ts);
     }
@@ -199,7 +227,6 @@ public class Put extends Mutation implements HeapSize, Comparable<Row> {
    * This expects that the underlying arrays won't change. It's intended
    * for usage internal HBase to and for advanced client applications.
    */
-  @SuppressWarnings("unchecked")
   public Put addImmutable(byte[] family, byte[] qualifier, long ts, byte[] value, Tag[] tag) {
     List<Cell> list = getCellList(family);
     KeyValue kv = createPutKeyValue(family, qualifier, ts, value, tag);
@@ -233,8 +260,23 @@ public class Put extends Mutation implements HeapSize, Comparable<Row> {
    * @param ts version timestamp
    * @param value column value
    * @return this
+   * @deprecated Since 1.0.0. Use {@link Put#addColumn(byte[], ByteBuffer, long, ByteBuffer)}
    */
+  @Deprecated
   public Put add(byte[] family, ByteBuffer qualifier, long ts, ByteBuffer value) {
+    return addColumn(family, qualifier, ts, value);
+  }
+
+  /**
+   * Add the specified column and value, with the specified timestamp as
+   * its version to this Put operation.
+   * @param family family name
+   * @param qualifier column qualifier
+   * @param ts version timestamp
+   * @param value column value
+   * @return this
+   */
+  public Put addColumn(byte[] family, ByteBuffer qualifier, long ts, ByteBuffer value) {
     if (ts < 0) {
       throw new IllegalArgumentException("Timestamp cannot be negative. ts=" + ts);
     }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionAdminServiceCallable.java

@@ -23,13 +23,17 @@ import java.io.InterruptedIOException;
 import java.net.ConnectException;
 import java.net.SocketTimeoutException;
 
+import org.apache.hadoop.hbase.DoNotRetryIOException;
 import org.apache.hadoop.hbase.HBaseIOException;
 import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.NotServingRegionException;
+import org.apache.hadoop.hbase.RegionLocations;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.exceptions.RegionMovedException;
+import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.AdminService;
+import org.apache.hadoop.hbase.util.Bytes;
 
 /**
  * Similar to {@link RegionServerCallable} but for the AdminService interface. This service callable
@@ -42,25 +46,39 @@ public abstract class RegionAdminServiceCallable<T> implements RetryingCallable<
 
   protected final ClusterConnection connection;
 
+  protected final RpcControllerFactory rpcControllerFactory;
+
   protected AdminService.BlockingInterface stub;
 
   protected HRegionLocation location;
 
   protected final TableName tableName;
   protected final byte[] row;
+  protected final int replicaId;
 
   protected final static int MIN_WAIT_DEAD_SERVER = 10000;
 
-  public RegionAdminServiceCallable(ClusterConnection connection, TableName tableName, byte[] row) {
+  public RegionAdminServiceCallable(ClusterConnection connection,
-    this(connection, null, tableName, row);
+      RpcControllerFactory rpcControllerFactory, TableName tableName, byte[] row) {
+    this(connection, rpcControllerFactory, null, tableName, row);
   }
 
-  public RegionAdminServiceCallable(ClusterConnection connection, HRegionLocation location,
+  public RegionAdminServiceCallable(ClusterConnection connection,
+      RpcControllerFactory rpcControllerFactory, HRegionLocation location,
       TableName tableName, byte[] row) {
+    this(connection, rpcControllerFactory, location,
+      tableName, row, RegionReplicaUtil.DEFAULT_REPLICA_ID);
+  }
+
+  public RegionAdminServiceCallable(ClusterConnection connection,
+      RpcControllerFactory rpcControllerFactory, HRegionLocation location,
+      TableName tableName, byte[] row, int replicaId) {
     this.connection = connection;
+    this.rpcControllerFactory = rpcControllerFactory;
     this.location = location;
     this.tableName = tableName;
     this.row = row;
+    this.replicaId = replicaId;
   }
 
   @Override
@@ -85,7 +103,18 @@ public abstract class RegionAdminServiceCallable<T> implements RetryingCallable<
     this.stub = stub;
   }
 
-  public abstract HRegionLocation getLocation(boolean useCache) throws IOException;
+  public HRegionLocation getLocation(boolean useCache) throws IOException {
+    RegionLocations rl = getRegionLocations(connection, tableName, row, useCache, replicaId);
+    if (rl == null) {
+      throw new HBaseIOException(getExceptionMessage());
+    }
+    HRegionLocation location = rl.getRegionLocation(replicaId);
+    if (location == null) {
+      throw new HBaseIOException(getExceptionMessage());
+    }
+
+    return location;
+  }
 
   @Override
   public void throwable(Throwable t, boolean retrying) {
@@ -115,7 +144,8 @@ public abstract class RegionAdminServiceCallable<T> implements RetryingCallable<
 
   //subclasses can override this.
   protected String getExceptionMessage() {
-    return "There is no location";
+    return "There is no location" + " table=" + tableName
+        + " ,replica=" + replicaId + ", row=" + Bytes.toStringBinary(row);
   }
 
   @Override
@@ -132,4 +162,27 @@ public abstract class RegionAdminServiceCallable<T> implements RetryingCallable<
     }
     return sleep;
   }
+
+  public static RegionLocations getRegionLocations(
+      ClusterConnection connection, TableName tableName, byte[] row,
+      boolean useCache, int replicaId)
+      throws RetriesExhaustedException, DoNotRetryIOException, InterruptedIOException {
+    RegionLocations rl;
+    try {
+      rl = connection.locateRegion(tableName, row, useCache, true, replicaId);
+    } catch (DoNotRetryIOException e) {
+      throw e;
+    } catch (RetriesExhaustedException e) {
+      throw e;
+    } catch (InterruptedIOException e) {
+      throw e;
+    } catch (IOException e) {
+      throw new RetriesExhaustedException("Can't get the location", e);
+    }
+    if (rl == null) {
+      throw new RetriesExhaustedException("Can't get the locations");
+    }
+
+    return rl;
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionReplicaUtil.java

@@ -23,6 +23,7 @@ import java.util.Iterator;
 
 import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.util.Bytes;
 
 /**
  * Utility methods which contain the logic for regions and replicas.
@@ -30,6 +31,19 @@ import org.apache.hadoop.hbase.classification.InterfaceAudience;
 @InterfaceAudience.Private
 public class RegionReplicaUtil {
 
+  /**
+   * Whether or not the secondary region will wait for observing a flush / region open event
+   * from the primary region via async wal replication before enabling read requests. Since replayed
+   * edits from async wal replication from primary is not persisted in WAL, the memstore of the
+   * secondary region might be non-empty at the time of close or crash. For ensuring seqId's not
+   * "going back in time" in the secondary region replica, this should be enabled. However, in some
+   * cases the above semantics might be ok for some application classes.
+   * See HBASE-11580 for more context.
+   */
+  public static final String REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY
+    = "hbase.region.replica.wait.for.primary.flush";
+  protected static final boolean DEFAULT_REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH = true;
+
   /**
    * The default replicaId for the region
    */
@@ -92,4 +106,46 @@ public class RegionReplicaUtil {
       }
     }
   }
+
+  public static boolean isReplicasForSameRegion(HRegionInfo regionInfoA, HRegionInfo regionInfoB) {
+    return compareRegionInfosWithoutReplicaId(regionInfoA, regionInfoB) == 0;
+  }
+
+  private static int compareRegionInfosWithoutReplicaId(HRegionInfo regionInfoA,
+      HRegionInfo regionInfoB) {
+    int result = regionInfoA.getTable().compareTo(regionInfoB.getTable());
+    if (result != 0) {
+      return result;
+    }
+
+    // Compare start keys.
+    result = Bytes.compareTo(regionInfoA.getStartKey(), regionInfoB.getStartKey());
+    if (result != 0) {
+      return result;
+    }
+
+    // Compare end keys.
+    result = Bytes.compareTo(regionInfoA.getEndKey(), regionInfoB.getEndKey());
+
+    if (result != 0) {
+      if (regionInfoA.getStartKey().length != 0
+              && regionInfoA.getEndKey().length == 0) {
+          return 1; // this is last region
+      }
+      if (regionInfoB.getStartKey().length != 0
+              && regionInfoB.getEndKey().length == 0) {
+          return -1; // o is the last region
+      }
+      return result;
+    }
+
+    // regionId is usually milli timestamp -- this defines older stamps
+    // to be "smaller" than newer stamps in sort order.
+    if (regionInfoA.getRegionId() > regionInfoB.getRegionId()) {
+      return 1;
+    } else if (regionInfoA.getRegionId() < regionInfoB.getRegionId()) {
+      return -1;
+    }
+    return 0;
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Result.java

@@ -19,6 +19,7 @@
 
 package org.apache.hadoop.hbase.client;
 
+import java.io.IOException;
 import java.nio.BufferOverflowException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
@@ -33,6 +34,7 @@ import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellScannable;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValueUtil;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
@@ -80,6 +82,17 @@ public class Result implements CellScannable, CellScanner {
   private Cell[] cells;
   private Boolean exists; // if the query was just to check existence.
   private boolean stale = false;
+
+  /**
+   * Partial results do not contain the full row's worth of cells. The result had to be returned in
+   * parts because the size of the cells in the row exceeded the RPC result size on the server.
+   * Partial results must be combined client side with results representing the remainder of the
+   * row's cells to form the complete result. Partial results and RPC result size allow us to avoid
+   * OOME on the server when servicing requests for large rows. The Scan configuration used to
+   * control the result size on the server is {@link Scan#setMaxResultSize(long)} and the default
+   * value can be seen here: {@link HConstants#DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE}
+   */
+  private boolean partial = false;
   // We're not using java serialization.  Transient here is just a marker to say
   // that this is where we cache row if we're ever asked for it.
   private transient byte [] row = null;
@@ -89,7 +102,7 @@ public class Result implements CellScannable, CellScanner {
 
   private static ThreadLocal<byte[]> localBuffer = new ThreadLocal<byte[]>();
   private static final int PAD_WIDTH = 128;
-  public static final Result EMPTY_RESULT = new Result();
+  public static final Result EMPTY_RESULT = new Result(true);
 
   private final static int INITIAL_CELLSCANNER_INDEX = -1;
 
@@ -99,6 +112,8 @@ public class Result implements CellScannable, CellScanner {
   private int cellScannerIndex = INITIAL_CELLSCANNER_INDEX;
   private ClientProtos.RegionLoadStats stats;
 
+  private final boolean readonly;
+
   /**
    * Creates an empty Result w/ no KeyValue payload; returns null if you call {@link #rawCells()}.
    * Use this to represent no results if {@code null} won't do or in old 'mapred' as opposed
@@ -106,7 +121,16 @@ public class Result implements CellScannable, CellScanner {
    * {@link #copyFrom(Result)} call.
    */
   public Result() {
-    super();
+    this(false);
+  }
+
+  /**
+   * Allows to construct special purpose immutable Result objects,
+   * such as EMPTY_RESULT.
+   * @param readonly whether this Result instance is readonly
+   */
+  private Result(boolean readonly) {
+    this.readonly = readonly;
   }
 
   /**
@@ -115,7 +139,7 @@ public class Result implements CellScannable, CellScanner {
    * @param cells List of cells
    */
   public static Result create(List<Cell> cells) {
-    return new Result(cells.toArray(new Cell[cells.size()]), null, false);
+    return create(cells, null);
   }
 
   public static Result create(List<Cell> cells, Boolean exists) {
@@ -123,10 +147,14 @@ public class Result implements CellScannable, CellScanner {
   }
 
   public static Result create(List<Cell> cells, Boolean exists, boolean stale) {
+    return create(cells, exists, stale, false);
+  }
+
+  public static Result create(List<Cell> cells, Boolean exists, boolean stale, boolean partial) {
     if (exists != null){
-      return new Result(null, exists, stale);
+      return new Result(null, exists, stale, partial);
     }
-    return new Result(cells.toArray(new Cell[cells.size()]), null, stale);
+    return new Result(cells.toArray(new Cell[cells.size()]), null, stale, partial);
   }
 
   /**
@@ -135,21 +163,27 @@ public class Result implements CellScannable, CellScanner {
    * @param cells array of cells
    */
   public static Result create(Cell[] cells) {
-    return new Result(cells, null, false);
+    return create(cells, null, false);
   }
 
   public static Result create(Cell[] cells, Boolean exists, boolean stale) {
+    return create(cells, exists, stale, false);
+  }
+
+  public static Result create(Cell[] cells, Boolean exists, boolean stale, boolean partial) {
     if (exists != null){
-      return new Result(null, exists, stale);
+      return new Result(null, exists, stale, partial);
     }
-    return new Result(cells, null, stale);
+    return new Result(cells, null, stale, partial);
   }
 
   /** Private ctor. Use {@link #create(Cell[])}. */
-  private Result(Cell[] cells, Boolean exists, boolean stale) {
+  private Result(Cell[] cells, Boolean exists, boolean stale, boolean partial) {
     this.cells = cells;
     this.exists = exists;
     this.stale = stale;
+    this.partial = partial;
+    this.readonly = false;
   }
 
   /**
@@ -361,6 +395,9 @@ public class Result implements CellScannable, CellScanner {
 
   /**
    * Get the latest version of the specified column.
+   * Note: this call clones the value content of the hosting Cell. See
+   * {@link #getValueAsByteBuffer(byte[], byte[])}, etc., or {@link #listCells()} if you would
+   * avoid the cloning.
    * @param family family name
    * @param qualifier column qualifier
    * @return value of latest version of column, null if none found
@@ -388,7 +425,8 @@ public class Result implements CellScannable, CellScanner {
     if (kv == null) {
       return null;
     }
-    return ByteBuffer.wrap(kv.getValueArray(), kv.getValueOffset(), kv.getValueLength());
+    return ByteBuffer.wrap(kv.getValueArray(), kv.getValueOffset(), kv.getValueLength()).
+      asReadOnlyBuffer();
   }
 
   /**
@@ -411,7 +449,8 @@ public class Result implements CellScannable, CellScanner {
     if (kv == null) {
       return null;
     }
-    return ByteBuffer.wrap(kv.getValueArray(), kv.getValueOffset(), kv.getValueLength());
+    return ByteBuffer.wrap(kv.getValueArray(), kv.getValueOffset(), kv.getValueLength()).
+      asReadOnlyBuffer();
   }
 
   /**
@@ -741,7 +780,59 @@ public class Result implements CellScannable, CellScanner {
   }
 
   /**
-   * Get total size of raw cells 
+   * Forms a single result from the partial results in the partialResults list. This method is
+   * useful for reconstructing partial results on the client side.
+   * @param partialResults list of partial results
+   * @return The complete result that is formed by combining all of the partial results together
+   * @throws IOException A complete result cannot be formed because the results in the partial list
+   *           come from different rows
+   */
+  public static Result createCompleteResult(List<Result> partialResults)
+      throws IOException {
+    List<Cell> cells = new ArrayList<Cell>();
+    boolean stale = false;
+    byte[] prevRow = null;
+    byte[] currentRow = null;
+
+    if (partialResults != null && !partialResults.isEmpty()) {
+      for (int i = 0; i < partialResults.size(); i++) {
+        Result r = partialResults.get(i);
+        currentRow = r.getRow();
+        if (prevRow != null && !Bytes.equals(prevRow, currentRow)) {
+          throw new IOException(
+              "Cannot form complete result. Rows of partial results do not match." +
+                  " Partial Results: " + partialResults);
+        }
+
+        // Ensure that all Results except the last one are marked as partials. The last result
+        // may not be marked as a partial because Results are only marked as partials when
+        // the scan on the server side must be stopped due to reaching the maxResultSize.
+        // Visualizing it makes it easier to understand:
+        // maxResultSize: 2 cells
+        // (-x-) represents cell number x in a row
+        // Example: row1: -1- -2- -3- -4- -5- (5 cells total)
+        // How row1 will be returned by the server as partial Results:
+        // Result1: -1- -2- (2 cells, size limit reached, mark as partial)
+        // Result2: -3- -4- (2 cells, size limit reached, mark as partial)
+        // Result3: -5- (1 cell, size limit NOT reached, NOT marked as partial)
+        if (i != (partialResults.size() - 1) && !r.isPartial()) {
+          throw new IOException(
+              "Cannot form complete result. Result is missing partial flag. " +
+                  "Partial Results: " + partialResults);
+        }
+        prevRow = currentRow;
+        stale = stale || r.isStale();
+        for (Cell c : r.rawCells()) {
+          cells.add(c);
+        }
+      }
+    }
+
+    return Result.create(cells, null, stale);
+  }
+
+  /**
+   * Get total size of raw cells
    * @param result
    * @return Total size.
    */
@@ -755,9 +846,12 @@ public class Result implements CellScannable, CellScanner {
 
   /**
    * Copy another Result into this one. Needed for the old Mapred framework
+   * @throws UnsupportedOperationException if invoked on instance of EMPTY_RESULT
+   * (which is supposed to be immutable).
    * @param other
    */
   public void copyFrom(Result other) {
+    checkReadonly();
     this.row = null;
     this.familyMap = null;
     this.cells = other.cells;
@@ -787,6 +881,7 @@ public class Result implements CellScannable, CellScanner {
   }
 
   public void setExists(Boolean exists) {
+    checkReadonly();
     this.exists = exists;
   }
 
@@ -799,11 +894,34 @@ public class Result implements CellScannable, CellScanner {
     return stale;
   }
 
+  /**
+   * Whether or not the result is a partial result. Partial results contain a subset of the cells
+   * for a row and should be combined with a result representing the remaining cells in that row to
+   * form a complete (non-partial) result.
+   * @return Whether or not the result is a partial result
+   */
+  public boolean isPartial() {
+    return partial;
+  }
+
   /**
    * Add load information about the region to the information about the result
    * @param loadStats statistics about the current region from which this was returned
+   * @deprecated use {@link #setStatistics(ClientProtos.RegionLoadStats)} instead
+   * @throws UnsupportedOperationException if invoked on instance of EMPTY_RESULT
+   * (which is supposed to be immutable).
    */
+  @Deprecated
   public void addResults(ClientProtos.RegionLoadStats loadStats) {
+    checkReadonly();
+    this.stats = loadStats;
+  }
+
+  /**
+   * Set load information about the region to the information about the result
+   * @param loadStats statistics about the current region from which this was returned
+   */
+  public void setStatistics(ClientProtos.RegionLoadStats loadStats) {
     this.stats = loadStats;
   }
 
@@ -814,4 +932,14 @@ public class Result implements CellScannable, CellScanner {
   public ClientProtos.RegionLoadStats getStats() {
     return stats;
   }
+
+  /**
+   * All methods modifying state of Result object must call this method
+   * to ensure that special purpose immutable Results can't be accidentally modified.
+   */
+  private void checkReadonly() {
+    if (readonly == true) {
+      throw new UnsupportedOperationException("Attempting to modify readonly EMPTY_RESULT!");
+    }
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/RetryingCallerInterceptorFactory.java

@@ -27,7 +27,7 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 
 /**
- * Factory implementation to provide the {@link HConnectionImplementation} with
+ * Factory implementation to provide the {@link ConnectionImplementation} with
  * the implementation of the {@link RetryingCallerInterceptor} that we would use
  * to intercept the {@link RpcRetryingCaller} during the course of their calls.
  * 

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ReversedClientScanner.java

@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.client;
 
 import java.io.IOException;
-import java.util.Arrays;
 import java.util.concurrent.ExecutorService;
 
 import org.apache.commons.logging.Log;
@@ -38,9 +37,6 @@ import org.apache.hadoop.hbase.util.ExceptionUtil;
 @InterfaceAudience.Private
 public class ReversedClientScanner extends ClientScanner {
   private static final Log LOG = LogFactory.getLog(ReversedClientScanner.class);
-  // A byte array in which all elements are the max byte, and it is used to
-  // construct closest front row
-  static byte[] MAX_BYTE_ARRAY = Bytes.createMaxByteArray(9);
 
   /**
    * Create a new ReversibleClientScanner for the specified table Note that the
@@ -139,9 +135,10 @@ public class ReversedClientScanner extends ClientScanner {
         new ReversedScannerCallable(getConnection(), getTable(), scan, this.scanMetrics,
             locateStartRow, this.rpcControllerFactory);
     s.setCaching(nbRows);
-    ScannerCallableWithReplicas sr = new ScannerCallableWithReplicas(getTable(), getConnection(),
+    ScannerCallableWithReplicas sr =
-        s, pool, primaryOperationTimeout, scan,
+        new ScannerCallableWithReplicas(getTable(), getConnection(), s, pool,
-        getRetries(), getScannerTimeout(), caching, getConf(), caller);
+            primaryOperationTimeout, scan, getRetries(), getScannerTimeout(), caching, getConf(),
+            caller);
     return sr;
   }
 
@@ -161,26 +158,4 @@ public class ReversedClientScanner extends ClientScanner {
     }
     return false; // unlikely.
   }
-
-  /**
-   * Create the closest row before the specified row
-   * @param row
-   * @return a new byte array which is the closest front row of the specified one
-   */
-  protected static byte[] createClosestRowBefore(byte[] row) {
-    if (row == null) {
-      throw new IllegalArgumentException("The passed row is empty");
-    }
-    if (Bytes.equals(row, HConstants.EMPTY_BYTE_ARRAY)) {
-      return MAX_BYTE_ARRAY;
-    }
-    if (row[row.length - 1] == 0) {
-      return Arrays.copyOf(row, row.length - 1);
-    } else {
-      byte[] closestFrontRow = Arrays.copyOf(row, row.length);
-      closestFrontRow[row.length - 1] = (byte) ((closestFrontRow[row.length - 1] & 0xff) - 1);
-      closestFrontRow = Bytes.add(closestFrontRow, MAX_BYTE_ARRAY);
-      return closestFrontRow;
-    }
-  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ReversedScannerCallable.java

@@ -129,8 +129,6 @@ public class ReversedScannerCallable extends ScannerCallable {
     }
 
     // check how often we retry.
-    // HConnectionManager will call instantiateServer with reload==true
-    // if and only if for retries.
     if (reload && this.scanMetrics != null) {
       this.scanMetrics.countOfRPCRetries.incrementAndGet();
       if (isRegionServerRemote) {

hbase-client/src/main/java/org/apache/hadoop/hbase/client/RpcRetryingCallerImpl.java

@@ -54,10 +54,7 @@ public class RpcRetryingCallerImpl<T> implements RpcRetryingCaller<T> {
    * When we started making calls.
    */
   private long globalStartTime;
-  /**
+
-   * Start and end times for a single call.
-   */
-  private final static int MIN_RPC_TIMEOUT = 2000;
   /** How many retries are allowed before we start to log */
   private final int startLogErrorsCnt;
 
@@ -87,11 +84,11 @@ public class RpcRetryingCallerImpl<T> implements RpcRetryingCaller<T> {
       if (callTimeout == Integer.MAX_VALUE) return Integer.MAX_VALUE;
       int remainingTime = (int) (callTimeout -
           (EnvironmentEdgeManager.currentTime() - this.globalStartTime));
-      if (remainingTime < MIN_RPC_TIMEOUT) {
+      if (remainingTime < 1) {
         // If there is no time left, we're trying anyway. It's too late.
         // 0 means no timeout, and it's not the intent here. So we secure both cases by
         // resetting to the minimum.
-        remainingTime = MIN_RPC_TIMEOUT;
+        remainingTime = 1;
       }
       return remainingTime;
     }
@@ -222,7 +219,7 @@ public class RpcRetryingCallerImpl<T> implements RpcRetryingCaller<T> {
       }
       // Don't let ServiceException out; its rpc specific.
       t = cause;
-      // t could be a RemoteException so go aaround again.
+      // t could be a RemoteException so go around again.
       translateException(t);
     } else if (t instanceof DoNotRetryIOException) {
       throw (DoNotRetryIOException)t;

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Scan.java

@@ -34,9 +34,11 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
+import org.apache.hadoop.hbase.client.metrics.ScanMetrics;
 import org.apache.hadoop.hbase.filter.Filter;
 import org.apache.hadoop.hbase.filter.IncompatibleFilterException;
 import org.apache.hadoop.hbase.io.TimeRange;
+import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.security.access.Permission;
 import org.apache.hadoop.hbase.security.visibility.Authorizations;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -91,35 +93,40 @@ public class Scan extends Query {
 
   private static final String RAW_ATTR = "_raw_";
 
-  /**
-   * EXPERT ONLY.
-   * An integer (not long) indicating to the scanner logic how many times we attempt to retrieve the
-   * next KV before we schedule a reseek.
-   * The right value depends on the size of the average KV. A reseek is more efficient when
-   * it can skip 5-10 KVs or 512B-1KB, or when the next KV is likely found in another HFile block.
-   * Setting this only has any effect when columns were added with
-   * {@link #addColumn(byte[], byte[])}
-   * <pre>{@code
-   * Scan s = new Scan(...);
-   * s.addColumn(...);
-   * s.setAttribute(Scan.HINT_LOOKAHEAD, Bytes.toBytes(2));
-   * }</pre>
-   * Default is 0 (always reseek).
-   */
-  public static final String HINT_LOOKAHEAD = "_look_ahead_";
-
   private byte [] startRow = HConstants.EMPTY_START_ROW;
   private byte [] stopRow  = HConstants.EMPTY_END_ROW;
   private int maxVersions = 1;
   private int batch = -1;
 
+  /**
+   * Partial {@link Result}s are {@link Result}s must be combined to form a complete {@link Result}.
+   * The {@link Result}s had to be returned in fragments (i.e. as partials) because the size of the
+   * cells in the row exceeded max result size on the server. Typically partial results will be
+   * combined client side into complete results before being delivered to the caller. However, if
+   * this flag is set, the caller is indicating that they do not mind seeing partial results (i.e.
+   * they understand that the results returned from the Scanner may only represent part of a
+   * particular row). In such a case, any attempt to combine the partials into a complete result on
+   * the client side will be skipped, and the caller will be able to see the exact results returned
+   * from the server.
+   */
+  private boolean allowPartialResults = false;
+
   private int storeLimit = -1;
   private int storeOffset = 0;
   private boolean getScan;
 
-  // If application wants to collect scan metrics, it needs to
+  /**
-  // call scan.setAttribute(SCAN_ATTRIBUTES_ENABLE, Bytes.toBytes(Boolean.TRUE))
+   * @deprecated since 1.0.0. Use {@link #setScanMetricsEnabled(boolean)}
+   */
+  // Make private or remove.
+  @Deprecated
   static public final String SCAN_ATTRIBUTES_METRICS_ENABLE = "scan.attributes.metrics.enable";
+
+  /**
+   * Use {@link #getScanMetrics()}
+   */
+  // Make this private or remove.
+  @Deprecated
   static public final String SCAN_ATTRIBUTES_METRICS_DATA = "scan.attributes.metrics.data";
 
   // If an application wants to use multiple scans over different tables each scan must
@@ -680,6 +687,27 @@ public class Scan extends Query {
     return reversed;
   }
 
+  /**
+   * Setting whether the caller wants to see the partial results that may be returned from the
+   * server. By default this value is false and the complete results will be assembled client side
+   * before being delivered to the caller.
+   * @param allowPartialResults
+   * @return this
+   */
+  public Scan setAllowPartialResults(final boolean allowPartialResults) {
+    this.allowPartialResults = allowPartialResults;
+    return this;
+  }
+
+  /**
+   * @return true when the constructor of this scan understands that the results they will see may
+   *         only represent a partial portion of a row. The entire row would be retrieved by
+   *         subsequent calls to {@link ResultScanner#next()}
+   */
+  public boolean getAllowPartialResults() {
+    return allowPartialResults;
+  }
+
   /**
    * Set the value indicating whether loading CFs on demand should be allowed (cluster
    * default is false). On-demand CF loading doesn't load column families until necessary, e.g.
@@ -916,4 +944,31 @@ public class Scan extends Query {
     scan.setCaching(1);
     return scan;
   }
+
+  /**
+   * Enable collection of {@link ScanMetrics}. For advanced users.
+   * @param enabled Set to true to enable accumulating scan metrics
+   */
+  public Scan setScanMetricsEnabled(final boolean enabled) {
+    setAttribute(Scan.SCAN_ATTRIBUTES_METRICS_ENABLE, Bytes.toBytes(Boolean.valueOf(enabled)));
+    return this;
+  }
+
+  /**
+   * @return True if collection of scan metrics is enabled. For advanced users.
+   */
+  public boolean isScanMetricsEnabled() {
+    byte[] attr = getAttribute(Scan.SCAN_ATTRIBUTES_METRICS_ENABLE);
+    return attr == null ? false : Bytes.toBoolean(attr);
+  }
+
+  /**
+   * @return Metrics on this Scan, if metrics were enabled.
+   * @see #setScanMetricsEnabled(boolean)
+   */
+  public ScanMetrics getScanMetrics() {
+    byte [] bytes = getAttribute(Scan.SCAN_ATTRIBUTES_METRICS_DATA);
+    if (bytes == null) return null;
+    return ProtobufUtil.toScanMetrics(bytes);
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ScannerCallable.java

@@ -76,6 +76,8 @@ public class ScannerCallable extends RegionServerCallable<Result[]> {
   private int logCutOffLatency = 1000;
   private static String myAddress;
   protected final int id;
+  protected boolean serverHasMoreResultsContext;
+  protected boolean serverHasMoreResults;
   static {
     try {
       myAddress = DNS.getDefaultHost("default", "default");
@@ -153,8 +155,6 @@ public class ScannerCallable extends RegionServerCallable<Result[]> {
     }
 
     // check how often we retry.
-    // HConnectionManager will call instantiateServer with reload==true
-    // if and only if for retries.
     if (reload && this.scanMetrics != null) {
       this.scanMetrics.countOfRPCRetries.incrementAndGet();
       if (isRegionServerRemote) {
@@ -177,7 +177,6 @@ public class ScannerCallable extends RegionServerCallable<Result[]> {
 
 
   @Override
-  @SuppressWarnings("deprecation")
   public Result [] call(int callTimeout) throws IOException {
     if (Thread.interrupted()) {
       throw new InterruptedIOException();
@@ -223,12 +222,23 @@ public class ScannerCallable extends RegionServerCallable<Result[]> {
                   + rows + " rows from scanner=" + scannerId);
               }
             }
-            if (response.hasMoreResults()
+            // moreResults is only used for the case where a filter exhausts all elements
-                && !response.getMoreResults()) {
+            if (response.hasMoreResults() && !response.getMoreResults()) {
               scannerId = -1L;
               closed = true;
+              // Implied that no results were returned back, either.
               return null;
             }
+            // moreResultsInRegion explicitly defines when a RS may choose to terminate a batch due
+            // to size or quantity of results in the response.
+            if (response.hasMoreResultsInRegion()) {
+              // Set what the RS said
+              setHasMoreResultsContext(true);
+              setServerHasMoreResults(response.getMoreResultsInRegion());
+            } else {
+              // Server didn't respond whether it has more results or not.
+              setHasMoreResultsContext(false);
+            }
           } catch (ServiceException se) {
             throw ProtobufUtil.getRemoteException(se);
           }
@@ -394,4 +404,30 @@ public class ScannerCallable extends RegionServerCallable<Result[]> {
     s.setCaching(this.caching);
     return s;
   }
+
+  /**
+   * Should the client attempt to fetch more results from this region
+   * @return True if the client should attempt to fetch more results, false otherwise.
+   */
+  protected boolean getServerHasMoreResults() {
+    assert serverHasMoreResultsContext;
+    return this.serverHasMoreResults;
+  }
+
+  protected void setServerHasMoreResults(boolean serverHasMoreResults) {
+    this.serverHasMoreResults = serverHasMoreResults;
+  }
+
+  /**
+   * Did the server respond with information about whether more results might exist.
+   * Not guaranteed to respond with older server versions
+   * @return True if the server responded with information about more results.
+   */
+  protected boolean hasMoreResultsContext() {
+    return serverHasMoreResultsContext;
+  }
+
+  protected void setHasMoreResultsContext(boolean serverHasMoreResultsContext) {
+    this.serverHasMoreResultsContext = serverHasMoreResultsContext;
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ScannerCallableWithReplicas.java

@@ -18,6 +18,8 @@
 
 package org.apache.hadoop.hbase.client;
 
+import static org.apache.hadoop.hbase.client.ClientScanner.createClosestRowBefore;
+
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.util.ArrayList;
@@ -44,8 +46,6 @@ import org.apache.hadoop.hbase.util.Pair;
 
 import com.google.common.annotations.VisibleForTesting;
 
-import static org.apache.hadoop.hbase.client.ReversedClientScanner.createClosestRowBefore;
-
 /**
  * This class has the logic for handling scanners for regions with and without replicas.
  * 1. A scan is attempted on the default (primary) region
@@ -111,6 +111,22 @@ class ScannerCallableWithReplicas implements RetryingCallable<Result[]> {
     return currentScannerCallable.getHRegionInfo();
   }
 
+  public boolean getServerHasMoreResults() {
+    return currentScannerCallable.getServerHasMoreResults();
+  }
+
+  public void setServerHasMoreResults(boolean serverHasMoreResults) {
+    currentScannerCallable.setServerHasMoreResults(serverHasMoreResults);
+  }
+
+  public boolean hasMoreResultsContext() {
+    return currentScannerCallable.hasMoreResultsContext();
+  }
+
+  public void setHasMoreResultsContext(boolean serverHasMoreResultsContext) {
+    currentScannerCallable.setHasMoreResultsContext(serverHasMoreResultsContext);
+  }
+
   @Override
   public Result [] call(int timeout) throws IOException {
     // If the active replica callable was closed somewhere, invoke the RPC to
@@ -276,14 +292,7 @@ class ScannerCallableWithReplicas implements RetryingCallable<Result[]> {
         continue; //this was already scheduled earlier
       }
       ScannerCallable s = currentScannerCallable.getScannerCallableForReplica(id);
-
+      setStartRowForReplicaCallable(s);
-      if (this.lastResult != null) {
-        if(s.getScan().isReversed()){
-          s.getScan().setStartRow(createClosestRowBefore(this.lastResult.getRow()));
-        }else {
-          s.getScan().setStartRow(Bytes.add(this.lastResult.getRow(), new byte[1]));
-        }
-      }
       outstandingCallables.add(s);
       RetryingRPC retryingOnReplica = new RetryingRPC(s);
       cs.submit(retryingOnReplica, scannerTimeout, id);
@@ -291,6 +300,31 @@ class ScannerCallableWithReplicas implements RetryingCallable<Result[]> {
     return max - min + 1;
   }
 
+  /**
+   * Set the start row for the replica callable based on the state of the last result received.
+   * @param callable The callable to set the start row on
+   */
+  private void setStartRowForReplicaCallable(ScannerCallable callable) {
+    if (this.lastResult == null || callable == null) return;
+
+    if (this.lastResult.isPartial()) {
+      // The last result was a partial result which means we have not received all of the cells
+      // for this row. Thus, use the last result's row as the start row. If a replica switch
+      // occurs, the scanner will ensure that any accumulated partial results are cleared,
+      // and the scan can resume from this row.
+      callable.getScan().setStartRow(this.lastResult.getRow());
+    } else {
+      // The last result was not a partial result which means it contained all of the cells for
+      // that row (we no longer need any information from it). Set the start row to the next
+      // closest row that could be seen.
+      if (callable.getScan().isReversed()) {
+        callable.getScan().setStartRow(createClosestRowBefore(this.lastResult.getRow()));
+      } else {
+        callable.getScan().setStartRow(Bytes.add(this.lastResult.getRow(), new byte[1]));
+      }
+    }
+  }
+
   @VisibleForTesting
   boolean isAnyRPCcancelled() {
     return someRPCcancelled;

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Table.java

@@ -498,7 +498,9 @@ public interface Table extends Closeable {
    * The default value comes from the configuration parameter
    * {@code hbase.client.write.buffer}.
    * @return The size of the write buffer in bytes.
+    * @deprecated as of 1.0.1 (should not have been in 1.0.0). Replaced by {@link BufferedMutator#getWriteBufferSize()}
    */
+  @Deprecated
   long getWriteBufferSize();
 
   /**
@@ -508,7 +510,10 @@ public interface Table extends Closeable {
    * write buffer, the buffer gets flushed.
    * @param writeBufferSize The new write buffer size, in bytes.
    * @throws IOException if a remote or network exception occurs.
+   * @deprecated as of 1.0.1 (should not have been in 1.0.0). Replaced by {@link BufferedMutator} and
+   * {@link BufferedMutatorParams#writeBufferSize(long)}
    */
+  @Deprecated
   void setWriteBufferSize(long writeBufferSize) throws IOException;
 
   /**

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ZooKeeperKeepAliveConnection.java

@@ -39,14 +39,14 @@ import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
 class ZooKeeperKeepAliveConnection extends ZooKeeperWatcher{
   ZooKeeperKeepAliveConnection(
     Configuration conf, String descriptor,
-    ConnectionManager.HConnectionImplementation conn) throws IOException {
+    ConnectionImplementation conn) throws IOException {
     super(conf, descriptor, conn);
   }
 
   @Override
   public void close() {
     if (this.abortable != null) {
-      ((ConnectionManager.HConnectionImplementation)abortable).releaseZooKeeperWatcher(this);
+      ((ConnectionImplementation)abortable).releaseZooKeeperWatcher(this);
     }
   }
 

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ZooKeeperRegistry.java

@@ -37,14 +37,14 @@ import org.apache.zookeeper.KeeperException;
 class ZooKeeperRegistry implements Registry {
   static final Log LOG = LogFactory.getLog(ZooKeeperRegistry.class);
   // Needs an instance of hci to function.  Set after construct this instance.
-  ConnectionManager.HConnectionImplementation hci;
+  ConnectionImplementation hci;
 
   @Override
   public void init(Connection connection) {
-    if (!(connection instanceof ConnectionManager.HConnectionImplementation)) {
+    if (!(connection instanceof ConnectionImplementation)) {
-      throw new RuntimeException("This registry depends on HConnectionImplementation");
+      throw new RuntimeException("This registry depends on ConnectionImplementation");
     }
-    this.hci = (ConnectionManager.HConnectionImplementation)connection;
+    this.hci = (ConnectionImplementation)connection;
   }
 
   @Override

hbase-client/src/main/java/org/apache/hadoop/hbase/client/metrics/ScanMetrics.java

@@ -22,15 +22,14 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.classification.InterfaceStability;
 
 import com.google.common.collect.ImmutableMap;
 
 
 /**
- * Provides client-side metrics related to scan operations
+ * Provides client-side metrics related to scan operations.
  * The data can be passed to mapreduce framework or other systems.
  * We use atomic longs so that one thread can increment,
  * while another atomically resets to zero after the values are reported
@@ -40,12 +39,10 @@ import com.google.common.collect.ImmutableMap;
  * However, there is no need for this. So they are defined under scan operation
  * for now.
  */
-@InterfaceAudience.Private
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
 public class ScanMetrics {
 
-
-  private static final Log LOG = LogFactory.getLog(ScanMetrics.class);
-
   /**
    * Hash to hold the String -> Atomic Long mappings.
    */

hbase-client/src/main/java/org/apache/hadoop/hbase/client/replication/ReplicationAdmin.java

@@ -38,17 +38,25 @@ import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
+import org.apache.hadoop.hbase.client.RegionLocator;
 import org.apache.hadoop.hbase.replication.ReplicationException;
 import org.apache.hadoop.hbase.replication.ReplicationFactory;
+import org.apache.hadoop.hbase.replication.ReplicationPeer;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerZKImpl;
 import org.apache.hadoop.hbase.replication.ReplicationPeers;
 import org.apache.hadoop.hbase.replication.ReplicationQueuesClient;
+import org.apache.hadoop.hbase.util.Pair;
+import org.apache.hadoop.hbase.zookeeper.ZKUtil;
 import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
+import org.apache.zookeeper.KeeperException;
+import org.apache.zookeeper.data.Stat;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.Lists;
@@ -114,16 +122,31 @@ public class ReplicationAdmin implements Closeable {
           "enable it in order to use replication");
     }
     this.connection = ConnectionFactory.createConnection(conf);
-    zkw = createZooKeeperWatcher();
     try {
-      this.replicationPeers = ReplicationFactory.getReplicationPeers(zkw, conf, this.connection);
+      zkw = createZooKeeperWatcher();
-      this.replicationPeers.init();
+      try {
-      this.replicationQueuesClient =
+        this.replicationPeers = ReplicationFactory.getReplicationPeers(zkw, conf, this.connection);
-          ReplicationFactory.getReplicationQueuesClient(zkw, conf, this.connection);
+        this.replicationPeers.init();
-      this.replicationQueuesClient.init();
+        this.replicationQueuesClient =
-
+            ReplicationFactory.getReplicationQueuesClient(zkw, conf, this.connection);
-    } catch (ReplicationException e) {
+        this.replicationQueuesClient.init();
-      throw new IOException("Error initializing the replication admin client.", e);
+      } catch (Exception exception) {
+        if (zkw != null) {
+          zkw.close();
+        }
+        throw exception;
+      }
+    } catch (Exception exception) {
+      if (connection != null) {
+        connection.close();
+      }
+      if (exception instanceof IOException) {
+        throw (IOException) exception;
+      } else if (exception instanceof RuntimeException) {
+        throw (RuntimeException) exception;
+      } else {
+        throw new IOException("Error initializing the replication admin client.", exception);
+      }
     }
   }
 
@@ -501,4 +524,203 @@ public class ReplicationAdmin implements Closeable {
 
     return replicationColFams;
   }
+
+  /**
+   * Enable a table's replication switch.
+   * @param tableName name of the table
+   * @throws IOException if a remote or network exception occurs
+   */
+  public void enableTableRep(final TableName tableName) throws IOException {
+    if (tableName == null) {
+      throw new IllegalArgumentException("Table name cannot be null");
+    }
+    try (Admin admin = this.connection.getAdmin()) {
+      if (!admin.tableExists(tableName)) {
+        throw new TableNotFoundException("Table '" + tableName.getNameAsString()
+            + "' does not exists.");
+      }
+    }
+    byte[][] splits = getTableSplitRowKeys(tableName);
+    checkAndSyncTableDescToPeers(tableName, splits);
+    setTableRep(tableName, true);
+  }
+
+  /**
+   * Disable a table's replication switch.
+   * @param tableName name of the table
+   * @throws IOException if a remote or network exception occurs
+   */
+  public void disableTableRep(final TableName tableName) throws IOException {
+    if (tableName == null) {
+      throw new IllegalArgumentException("Table name is null");
+    }
+    try (Admin admin = this.connection.getAdmin()) {
+      if (!admin.tableExists(tableName)) {
+        throw new TableNotFoundException("Table '" + tableName.getNamespaceAsString()
+            + "' does not exists.");
+      }
+    }
+    setTableRep(tableName, false);
+  }
+
+  /**
+   * Get the split row keys of table
+   * @param tableName table name
+   * @return array of split row keys
+   * @throws IOException
+   */
+  private byte[][] getTableSplitRowKeys(TableName tableName) throws IOException {
+    try (RegionLocator locator = connection.getRegionLocator(tableName);) {
+      byte[][] startKeys = locator.getStartKeys();
+      if (startKeys.length == 1) {
+        return null;
+      }
+      byte[][] splits = new byte[startKeys.length - 1][];
+      for (int i = 1; i < startKeys.length; i++) {
+        splits[i - 1] = startKeys[i];
+      }
+      return splits;
+    }
+  }
+
+  /**
+   * Connect to peer and check the table descriptor on peer:
+   * <ol>
+   * <li>Create the same table on peer when not exist.</li>
+   * <li>Throw exception if the table exists on peer cluster but descriptors are not same.</li>
+   * </ol>
+   * @param tableName name of the table to sync to the peer
+   * @param splits table split keys
+   * @throws IOException
+   */
+  private void checkAndSyncTableDescToPeers(final TableName tableName, final byte[][] splits)
+      throws IOException {
+    List<ReplicationPeer> repPeers = listValidReplicationPeers();
+    if (repPeers == null || repPeers.size() <= 0) {
+      throw new IllegalArgumentException("Found no peer cluster for replication.");
+    }
+    for (ReplicationPeer repPeer : repPeers) {
+      Configuration peerConf = repPeer.getConfiguration();
+      HTableDescriptor htd = null;
+      try (Connection conn = ConnectionFactory.createConnection(peerConf);
+          Admin admin = this.connection.getAdmin();
+          Admin repHBaseAdmin = conn.getAdmin()) {
+        htd = admin.getTableDescriptor(tableName);
+        HTableDescriptor peerHtd = null;
+        if (!repHBaseAdmin.tableExists(tableName)) {
+          repHBaseAdmin.createTable(htd, splits);
+        } else {
+          peerHtd = repHBaseAdmin.getTableDescriptor(tableName);
+          if (peerHtd == null) {
+            throw new IllegalArgumentException("Failed to get table descriptor for table "
+                + tableName.getNameAsString() + " from peer cluster " + repPeer.getId());
+          } else if (!peerHtd.equals(htd)) {
+            throw new IllegalArgumentException("Table " + tableName.getNameAsString()
+                + " exists in peer cluster " + repPeer.getId()
+                + ", but the table descriptors are not same when comapred with source cluster."
+                + " Thus can not enable the table's replication switch.");
+          }
+        }
+      }
+    }
+  }
+
+  private List<ReplicationPeer> listValidReplicationPeers() {
+    Map<String, ReplicationPeerConfig> peers = listPeerConfigs();
+    if (peers == null || peers.size() <= 0) {
+      return null;
+    }
+    List<ReplicationPeer> validPeers = new ArrayList<ReplicationPeer>(peers.size());
+    for (Entry<String, ReplicationPeerConfig> peerEntry : peers.entrySet()) {
+      String peerId = peerEntry.getKey();
+      String clusterKey = peerEntry.getValue().getClusterKey();
+      Configuration peerConf = new Configuration(this.connection.getConfiguration());
+      Stat s = null;
+      try {
+        ZKUtil.applyClusterKeyToConf(peerConf, clusterKey);
+        Pair<ReplicationPeerConfig, Configuration> pair = this.replicationPeers.getPeerConf(peerId);
+        ReplicationPeer peer = new ReplicationPeerZKImpl(peerConf, peerId, pair.getFirst());
+        s =
+            zkw.getRecoverableZooKeeper().exists(peerConf.get(HConstants.ZOOKEEPER_ZNODE_PARENT),
+              null);
+        if (null == s) {
+          LOG.info(peerId + ' ' + clusterKey + " is invalid now.");
+          continue;
+        }
+        validPeers.add(peer);
+      } catch (ReplicationException e) {
+        LOG.warn("Failed to get valid replication peers. "
+            + "Error connecting to peer cluster with peerId=" + peerId);
+        LOG.debug("Failure details to get valid replication peers.", e);
+        continue;
+      } catch (KeeperException e) {
+        LOG.warn("Failed to get valid replication peers. KeeperException code="
+            + e.code().intValue());
+        LOG.debug("Failure details to get valid replication peers.", e);
+        continue;
+      } catch (InterruptedException e) {
+        LOG.warn("Failed to get valid replication peers due to InterruptedException.");
+        LOG.debug("Failure details to get valid replication peers.", e);
+        Thread.currentThread().interrupt();
+        continue;
+      } catch (IOException e) {
+        LOG.warn("Failed to get valid replication peers due to IOException.");
+        LOG.debug("Failure details to get valid replication peers.", e);
+        continue;
+      }
+    }
+    return validPeers;
+  }
+
+  /**
+   * Set the table's replication switch if the table's replication switch is already not set.
+   * @param tableName name of the table
+   * @param isRepEnabled is replication switch enable or disable
+   * @throws IOException if a remote or network exception occurs
+   */
+  private void setTableRep(final TableName tableName, boolean isRepEnabled) throws IOException {
+    Admin admin = null;
+    try {
+      admin = this.connection.getAdmin();
+      HTableDescriptor htd = admin.getTableDescriptor(tableName);
+      if (isTableRepEnabled(htd) ^ isRepEnabled) {
+        boolean isOnlineSchemaUpdateEnabled =
+            this.connection.getConfiguration()
+                .getBoolean("hbase.online.schema.update.enable", true);
+        if (!isOnlineSchemaUpdateEnabled) {
+          admin.disableTable(tableName);
+        }
+        for (HColumnDescriptor hcd : htd.getFamilies()) {
+          hcd.setScope(isRepEnabled ? HConstants.REPLICATION_SCOPE_GLOBAL
+              : HConstants.REPLICATION_SCOPE_LOCAL);
+        }
+        admin.modifyTable(tableName, htd);
+        if (!isOnlineSchemaUpdateEnabled) {
+          admin.enableTable(tableName);
+        }
+      }
+    } finally {
+      if (admin != null) {
+        try {
+          admin.close();
+        } catch (IOException e) {
+          LOG.warn("Failed to close admin connection.");
+          LOG.debug("Details on failure to close admin connection.", e);
+        }
+      }
+    }
+  }
+
+  /**
+   * @param htd table descriptor details for the table to check
+   * @return true if table's replication switch is enabled
+   */
+  private boolean isTableRepEnabled(HTableDescriptor htd) {
+    for (HColumnDescriptor hcd : htd.getFamilies()) {
+      if (hcd.getScope() != HConstants.REPLICATION_SCOPE_GLOBAL) {
+        return false;
+      }
+    }
+    return true;
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/ConnectionClosingException.java

@@ -45,7 +45,7 @@ import org.apache.hadoop.hbase.classification.InterfaceStability;
 * Thrown when the client believes that we are trying to communicate to has
 * been repeatedly unresponsive for a while.
 *
-* On receiving such an exception. The HConnectionManager will skip all
+* On receiving such an exception. The ConnectionManager will skip all
 * retries and fast fail the operation.
 */
 @InterfaceAudience.Public

hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/PreemptiveFastFailException.java

@@ -29,7 +29,7 @@ import org.apache.hadoop.hbase.ServerName;
  * Thrown when the client believes that we are trying to communicate to has
  * been repeatedly unresponsive for a while.
  *
- * On receiving such an exception. The HConnectionManager will skip all
+ * On receiving such an exception. The ConnectionManager will skip all
  * retries and fast fail the operation.
  */
  @InterfaceAudience.Public

hbase-client/src/main/java/org/apache/hadoop/hbase/executor/EventType.java

@@ -37,22 +37,22 @@ public enum EventType {
   // Messages originating from RS (NOTE: there is NO direct communication from
   // RS to Master). These are a result of RS updates into ZK.
   // RS_ZK_REGION_CLOSING    (1),   // It is replaced by M_ZK_REGION_CLOSING(HBASE-4739)
-  
+
   /**
    * RS_ZK_REGION_CLOSED<br>
-   * 
+   *
    * RS has finished closing a region.
    */
   RS_ZK_REGION_CLOSED       (2, ExecutorType.MASTER_CLOSE_REGION),
   /**
    * RS_ZK_REGION_OPENING<br>
-   * 
+   *
    * RS is in process of opening a region.
    */
   RS_ZK_REGION_OPENING      (3, null),
   /**
    * RS_ZK_REGION_OPENED<br>
-   * 
+   *
    * RS has finished opening a region.
    */
   RS_ZK_REGION_OPENED       (4, ExecutorType.MASTER_OPEN_REGION),
@@ -70,7 +70,7 @@ public enum EventType {
   RS_ZK_REGION_SPLIT        (6, ExecutorType.MASTER_SERVER_OPERATIONS),
   /**
    * RS_ZK_REGION_FAILED_OPEN<br>
-   * 
+   *
    * RS failed to open a region.
    */
   RS_ZK_REGION_FAILED_OPEN  (7, ExecutorType.MASTER_CLOSE_REGION),
@@ -217,7 +217,7 @@ public enum EventType {
    * Master adds this region as closing in ZK
    */
   M_ZK_REGION_CLOSING       (51, null),
-  
+
   /**
    * Master controlled events to be executed on the master
    * M_SERVER_SHUTDOWN
@@ -232,14 +232,14 @@ public enum EventType {
   M_META_SERVER_SHUTDOWN    (72, ExecutorType.MASTER_META_SERVER_OPERATIONS),
   /**
    * Master controlled events to be executed on the master.<br>
-   * 
+   *
    * M_MASTER_RECOVERY<br>
    * Master is processing recovery of regions found in ZK RIT
    */
   M_MASTER_RECOVERY         (73, ExecutorType.MASTER_SERVER_OPERATIONS),
   /**
    * Master controlled events to be executed on the master.<br>
-   * 
+   *
    * M_LOG_REPLAY<br>
    * Master is processing log replay of failed region server
    */
@@ -247,18 +247,25 @@ public enum EventType {
 
   /**
    * RS controlled events to be executed on the RS.<br>
-   * 
+   *
    * RS_PARALLEL_SEEK
    */
   RS_PARALLEL_SEEK          (80, ExecutorType.RS_PARALLEL_SEEK),
-  
+
   /**
    * RS wal recovery work items(either creating recover.edits or directly replay wals)
    * to be executed on the RS.<br>
-   * 
+   *
    * RS_LOG_REPLAY
    */
-  RS_LOG_REPLAY             (81, ExecutorType.RS_LOG_REPLAY_OPS);
+  RS_LOG_REPLAY             (81, ExecutorType.RS_LOG_REPLAY_OPS),
+
+  /**
+   * RS flush triggering from secondary region replicas to primary region replica. <br>
+   *
+   * RS_REGION_REPLICA_FLUSH
+   */
+  RS_REGION_REPLICA_FLUSH   (82, ExecutorType.RS_REGION_REPLICA_FLUSH_OPS);
 
   private final int code;
   private final ExecutorType executor;

hbase-client/src/main/java/org/apache/hadoop/hbase/executor/ExecutorType.java

@@ -45,7 +45,8 @@ public enum ExecutorType {
   RS_CLOSE_ROOT              (24),
   RS_CLOSE_META              (25),
   RS_PARALLEL_SEEK           (26),
-  RS_LOG_REPLAY_OPS          (27);
+  RS_LOG_REPLAY_OPS          (27),
+  RS_REGION_REPLICA_FLUSH_OPS  (28);
 
   ExecutorType(int value) {}
 

hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnRangeFilter.java

@@ -133,7 +133,7 @@ public class ColumnRangeFilter extends FilterBase {
     }
 
     if (!this.minColumnInclusive && cmpMin == 0) {
-      return ReturnCode.SKIP;
+      return ReturnCode.NEXT_COL;
     }
 
     if (this.maxColumn == null) {

hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FamilyFilter.java

@@ -65,7 +65,7 @@ public class FamilyFilter extends CompareFilter {
     if (familyLength > 0) {
       if (doCompare(this.compareOp, this.comparator, v.getFamilyArray(),
           v.getFamilyOffset(), familyLength)) {
-        return ReturnCode.SKIP;
+        return ReturnCode.NEXT_ROW;
       }
     }
     return ReturnCode.INCLUDE;

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AsyncCall.java

@@ -72,7 +72,7 @@ public class AsyncCall extends DefaultPromise<Message> {
     this.responseDefaultType = responseDefaultType;
 
     this.startTime = EnvironmentEdgeManager.currentTime();
-    this.rpcTimeout = controller.getCallTimeout();
+    this.rpcTimeout = controller.hasCallTimeout() ? controller.getCallTimeout() : 0;
   }
 
   /**
@@ -84,9 +84,10 @@ public class AsyncCall extends DefaultPromise<Message> {
     return this.startTime;
   }
 
-  @Override public String toString() {
+  @Override
-    return "callId: " + this.id + " methodName: " + this.method.getName() + " param {" +
+  public String toString() {
-        (this.param != null ? ProtobufUtil.getShortTextFormat(this.param) : "") + "}";
+    return "callId: " + this.id + " methodName: " + this.method.getName() + " param {"
+        + (this.param != null ? ProtobufUtil.getShortTextFormat(this.param) : "") + "}";
   }
 
   /**

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AsyncRpcChannel.java

@@ -17,9 +17,6 @@
  */
 package org.apache.hadoop.hbase.ipc;
 
-import com.google.protobuf.Descriptors;
-import com.google.protobuf.Message;
-import com.google.protobuf.RpcCallback;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufOutputStream;
@@ -31,11 +28,29 @@ import io.netty.util.Timeout;
 import io.netty.util.TimerTask;
 import io.netty.util.concurrent.GenericFutureListener;
 import io.netty.util.concurrent.Promise;
+
+import java.io.IOException;
+import java.net.ConnectException;
+import java.net.InetSocketAddress;
+import java.net.SocketException;
+import java.nio.ByteBuffer;
+import java.security.PrivilegedExceptionAction;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+import javax.security.sasl.SaslException;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.exceptions.ConnectionClosingException;
+import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.protobuf.generated.AuthenticationProtos;
 import org.apache.hadoop.hbase.protobuf.generated.RPCProtos;
 import org.apache.hadoop.hbase.protobuf.generated.TracingProtos;
@@ -56,18 +71,9 @@ import org.apache.hadoop.security.token.TokenSelector;
 import org.apache.htrace.Span;
 import org.apache.htrace.Trace;
 
-import javax.security.sasl.SaslException;
+import com.google.protobuf.Descriptors;
-import java.io.IOException;
+import com.google.protobuf.Message;
-import java.net.ConnectException;
+import com.google.protobuf.RpcCallback;
-import java.net.InetSocketAddress;
-import java.net.SocketException;
-import java.nio.ByteBuffer;
-import java.security.PrivilegedExceptionAction;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Random;
-import java.util.concurrent.ConcurrentSkipListMap;
-import java.util.concurrent.TimeUnit;
 
 /**
  * Netty RPC channel
@@ -97,8 +103,6 @@ public class AsyncRpcChannel {
   final String serviceName;
   final InetSocketAddress address;
 
-  ConcurrentSkipListMap<Integer, AsyncCall> calls = new ConcurrentSkipListMap<>();
-
   private int ioFailureCounter = 0;
   private int connectFailureCounter = 0;
 
@@ -108,15 +112,18 @@ public class AsyncRpcChannel {
   private Token<? extends TokenIdentifier> token;
   private String serverPrincipal;
 
-  volatile boolean shouldCloseConnection = false;
+
-  private IOException closeException;
+  // NOTE: closed and connected flags below are only changed when a lock on pendingCalls
+  private final Map<Integer, AsyncCall> pendingCalls = new HashMap<Integer, AsyncCall>();
+  private boolean connected = false;
+  private boolean closed = false;
 
   private Timeout cleanupTimer;
 
   private final TimerTask timeoutTask = new TimerTask() {
-    @Override public void run(Timeout timeout) throws Exception {
+    @Override
-      cleanupTimer = null;
+    public void run(Timeout timeout) throws Exception {
-      cleanupCalls(false);
+      cleanupCalls();
     }
   };
 
@@ -183,10 +190,11 @@ public class AsyncRpcChannel {
               if (ticket == null) {
                 throw new FatalConnectionException("ticket/user is null");
               }
+              final UserGroupInformation realTicket = ticket;
               saslHandler = ticket.doAs(new PrivilegedExceptionAction<SaslClientHandler>() {
                 @Override
                 public SaslClientHandler run() throws IOException {
-                  return getSaslHandler(bootstrap);
+                  return getSaslHandler(realTicket, bootstrap);
                 }
               });
               if (saslHandler != null) {
@@ -213,15 +221,20 @@ public class AsyncRpcChannel {
     ch.pipeline()
         .addLast("frameDecoder", new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4, 0, 4));
     ch.pipeline().addLast(new AsyncServerResponseHandler(this));
-
     try {
       writeChannelHeader(ch).addListener(new GenericFutureListener<ChannelFuture>() {
-        @Override public void operationComplete(ChannelFuture future) throws Exception {
+        @Override
+        public void operationComplete(ChannelFuture future) throws Exception {
           if (!future.isSuccess()) {
             close(future.cause());
             return;
           }
-          for (AsyncCall call : calls.values()) {
+          List<AsyncCall> callsToWrite;
+          synchronized (pendingCalls) {
+            connected = true;
+            callsToWrite = new ArrayList<AsyncCall>(pendingCalls.values());
+          }
+          for (AsyncCall call : callsToWrite) {
             writeRequest(call);
           }
         }
@@ -233,24 +246,26 @@ public class AsyncRpcChannel {
 
   /**
    * Get SASL handler
-   *
    * @param bootstrap to reconnect to
    * @return new SASL handler
    * @throws java.io.IOException if handler failed to create
    */
-  private SaslClientHandler getSaslHandler(final Bootstrap bootstrap) throws IOException {
+  private SaslClientHandler getSaslHandler(final UserGroupInformation realTicket,
-    return new SaslClientHandler(authMethod, token, serverPrincipal, client.fallbackAllowed,
+      final Bootstrap bootstrap) throws IOException {
-        client.conf.get("hbase.rpc.protection",
+    return new SaslClientHandler(realTicket, authMethod, token, serverPrincipal,
-            SaslUtil.QualityOfProtection.AUTHENTICATION.name().toLowerCase()),
+        client.fallbackAllowed, client.conf.get("hbase.rpc.protection",
+          SaslUtil.QualityOfProtection.AUTHENTICATION.name().toLowerCase()),
         new SaslClientHandler.SaslExceptionHandler() {
-          @Override public void handle(int retryCount, Random random, Throwable cause) {
+          @Override
+          public void handle(int retryCount, Random random, Throwable cause) {
             try {
               // Handle Sasl failure. Try to potentially get new credentials
-              handleSaslConnectionFailure(retryCount, cause, ticket.getUGI());
+              handleSaslConnectionFailure(retryCount, cause, realTicket);
 
               // Try to reconnect
-              AsyncRpcClient.WHEEL_TIMER.newTimeout(new TimerTask() {
+              client.newTimeout(new TimerTask() {
-                @Override public void run(Timeout timeout) throws Exception {
+                @Override
+                public void run(Timeout timeout) throws Exception {
                   connect(bootstrap);
                 }
               }, random.nextInt(reloginMaxBackoff) + 1, TimeUnit.MILLISECONDS);
@@ -259,10 +274,11 @@ public class AsyncRpcChannel {
             }
           }
         }, new SaslClientHandler.SaslSuccessfulConnectHandler() {
-      @Override public void onSuccess(Channel channel) {
+          @Override
-        startHBaseConnection(channel);
+          public void onSuccess(Channel channel) {
-      }
+            startHBaseConnection(channel);
-    });
+          }
+        });
   }
 
   /**
@@ -274,7 +290,7 @@ public class AsyncRpcChannel {
    */
   private void retryOrClose(final Bootstrap bootstrap, int connectCounter, Throwable e) {
     if (connectCounter < client.maxRetries) {
-      AsyncRpcClient.WHEEL_TIMER.newTimeout(new TimerTask() {
+      client.newTimeout(new TimerTask() {
         @Override public void run(Timeout timeout) throws Exception {
           connect(bootstrap);
         }
@@ -295,66 +311,50 @@ public class AsyncRpcChannel {
   public Promise<Message> callMethod(final Descriptors.MethodDescriptor method,
       final PayloadCarryingRpcController controller, final Message request,
       final Message responsePrototype) {
-    if (shouldCloseConnection) {
+    final AsyncCall call =
-      Promise<Message> promise = channel.eventLoop().newPromise();
+        new AsyncCall(channel.eventLoop(), client.callIdCnt.getAndIncrement(), method, request,
-      promise.setFailure(new ConnectException());
+            controller, responsePrototype);
-      return promise;
-    }
-
-    final AsyncCall call = new AsyncCall(channel.eventLoop(), client.callIdCnt.getAndIncrement(),
-        method, request, controller, responsePrototype);
-
     controller.notifyOnCancel(new RpcCallback<Object>() {
       @Override
       public void run(Object parameter) {
-        calls.remove(call.id);
+        // TODO: do not need to call AsyncCall.setFailed?
+        synchronized (pendingCalls) {
+          pendingCalls.remove(call.id);
+        }
       }
     });
+    // TODO: this should be handled by PayloadCarryingRpcController.
     if (controller.isCanceled()) {
       // To finish if the call was cancelled before we set the notification (race condition)
       call.cancel(true);
       return call;
     }
 
-    calls.put(call.id, call);
+    synchronized (pendingCalls) {
-
+      if (closed) {
-    // check again, see https://issues.apache.org/jira/browse/HBASE-12951
+        Promise<Message> promise = channel.eventLoop().newPromise();
-    if (shouldCloseConnection) {
+        promise.setFailure(new ConnectException());
-      Promise<Message> promise = channel.eventLoop().newPromise();
+        return promise;
-      promise.setFailure(new ConnectException());
+      }
-      return promise;
+      pendingCalls.put(call.id, call);
+      // Add timeout for cleanup if none is present
+      if (cleanupTimer == null && call.getRpcTimeout() > 0) {
+        cleanupTimer =
+            client.newTimeout(timeoutTask, call.getRpcTimeout(),
+              TimeUnit.MILLISECONDS);
+      }
+      if (!connected) {
+        return call;
+      }
     }
-
+    writeRequest(call);
-    // Add timeout for cleanup if none is present
-    if (cleanupTimer == null) {
-      cleanupTimer = AsyncRpcClient.WHEEL_TIMER.newTimeout(timeoutTask, call.getRpcTimeout(),
-          TimeUnit.MILLISECONDS);
-    }
-
-    if(channel.isActive()) {
-      writeRequest(call);
-    }
-
     return call;
   }
 
-  /**
+  AsyncCall removePendingCall(int id) {
-   * Calls method and returns a promise
+    synchronized (pendingCalls) {
-   * @param method to call
+      return pendingCalls.remove(id);
-   * @param controller to run call with
-   * @param request to send
-   * @param responsePrototype for response message
-   * @return Promise to listen to result
-   * @throws java.net.ConnectException on connection failures
-   */
-  public Promise<Message> callMethodWithPromise(
-      final Descriptors.MethodDescriptor method, final PayloadCarryingRpcController controller,
-      final Message request, final Message responsePrototype) throws ConnectException {
-    if (shouldCloseConnection || !channel.isOpen()) {
-      throw new ConnectException();
     }
-
-    return this.callMethod(method, controller, request, responsePrototype);
   }
 
   /**
@@ -380,6 +380,7 @@ public class AsyncRpcChannel {
       headerBuilder.setCellBlockCompressorClass(client.compressor.getClass().getCanonicalName());
     }
 
+    headerBuilder.setVersionInfo(ProtobufUtil.getVersionInfo());
     RPCProtos.ConnectionHeader header = headerBuilder.build();
 
 
@@ -400,10 +401,6 @@ public class AsyncRpcChannel {
    */
   private void writeRequest(final AsyncCall call) {
     try {
-      if (shouldCloseConnection) {
-        return;
-      }
-
       final RPCProtos.RequestHeader.Builder requestHeaderBuilder = RPCProtos.RequestHeader
           .newBuilder();
       requestHeaderBuilder.setCallId(call.id)
@@ -439,25 +436,12 @@ public class AsyncRpcChannel {
         IPCUtil.write(out, rh, call.param, cellBlock);
       }
 
-      channel.writeAndFlush(b).addListener(new CallWriteListener(this,call));
+      channel.writeAndFlush(b).addListener(new CallWriteListener(this, call.id));
     } catch (IOException e) {
-      if (!shouldCloseConnection) {
+      close(e);
-        close(e);
-      }
     }
   }
 
-  /**
-   * Fail a call
-   *
-   * @param call  to fail
-   * @param cause of fail
-   */
-  void failCall(AsyncCall call, IOException cause) {
-    calls.remove(call.id);
-    call.setFailed(cause);
-  }
-
   /**
    * Set up server authorization
    *
@@ -550,18 +534,22 @@ public class AsyncRpcChannel {
    * @param e exception on close
    */
   public void close(final Throwable e) {
-    client.removeConnection(ConnectionId.hashCode(ticket,serviceName,address));
+    client.removeConnection(this);
 
     // Move closing from the requesting thread to the channel thread
     channel.eventLoop().execute(new Runnable() {
       @Override
       public void run() {
-        if (shouldCloseConnection) {
+        List<AsyncCall> toCleanup;
-          return;
+        synchronized (pendingCalls) {
+          if (closed) {
+            return;
+          }
+          closed = true;
+          toCleanup = new ArrayList<AsyncCall>(pendingCalls.values());
+          pendingCalls.clear();
         }
-
+        IOException closeException = null;
-        shouldCloseConnection = true;
-
         if (e != null) {
           if (e instanceof IOException) {
             closeException = (IOException) e;
@@ -569,16 +557,19 @@ public class AsyncRpcChannel {
             closeException = new IOException(e);
           }
         }
-
         // log the info
         if (LOG.isDebugEnabled() && closeException != null) {
-          LOG.debug(name + ": closing ipc connection to " + address + ": " +
+          LOG.debug(name + ": closing ipc connection to " + address, closeException);
-              closeException.getMessage());
+        }
+        if (cleanupTimer != null) {
+          cleanupTimer.cancel();
+          cleanupTimer = null;
+        }
+        for (AsyncCall call : toCleanup) {
+          call.setFailed(closeException != null ? closeException : new ConnectionClosingException(
+              "Call id=" + call.id + " on server " + address + " aborted: connection is closing"));
         }
-
-        cleanupCalls(true);
         channel.disconnect().addListener(ChannelFutureListener.CLOSE);
-
         if (LOG.isDebugEnabled()) {
           LOG.debug(name + ": closed");
         }
@@ -591,64 +582,37 @@ public class AsyncRpcChannel {
    *
    * @param cleanAll true if all calls should be cleaned, false for only the timed out calls
    */
-  public void cleanupCalls(boolean cleanAll) {
+  private void cleanupCalls() {
-    // Cancel outstanding timers
+    List<AsyncCall> toCleanup = new ArrayList<AsyncCall>();
-    if (cleanupTimer != null) {
+    long currentTime = EnvironmentEdgeManager.currentTime();
-      cleanupTimer.cancel();
+    long nextCleanupTaskDelay = -1L;
-      cleanupTimer = null;
+    synchronized (pendingCalls) {
-    }
+      for (Iterator<AsyncCall> iter = pendingCalls.values().iterator(); iter.hasNext();) {
-
+        AsyncCall call = iter.next();
-    if (cleanAll) {
-      for (AsyncCall call : calls.values()) {
-        synchronized (call) {
-          // Calls can be done on another thread so check before failing them
-          if(!call.isDone()) {
-            if (closeException == null) {
-              failCall(call, new ConnectionClosingException("Call id=" + call.id +
-                  " on server " + address + " aborted: connection is closing"));
-            } else {
-              failCall(call, closeException);
-            }
-          }
-        }
-      }
-    } else {
-      for (AsyncCall call : calls.values()) {
-        long waitTime = EnvironmentEdgeManager.currentTime() - call.getStartTime();
         long timeout = call.getRpcTimeout();
-        if (timeout > 0 && waitTime >= timeout) {
+        if (timeout > 0) {
-          synchronized (call) {
+          if (currentTime - call.getStartTime() >= timeout) {
-            // Calls can be done on another thread so check before failing them
+            iter.remove();
-            if (!call.isDone()) {
+            toCleanup.add(call);
-              closeException = new CallTimeoutException("Call id=" + call.id +
+          } else {
-                  ", waitTime=" + waitTime + ", rpcTimeout=" + timeout);
+            if (nextCleanupTaskDelay < 0 || timeout < nextCleanupTaskDelay) {
-              failCall(call, closeException);
+              nextCleanupTaskDelay = timeout;
             }
           }
-        } else {
-          // We expect the call to be ordered by timeout. It may not be the case, but stopping
-          //  at the first valid call allows to be sure that we still have something to do without
-          //  spending too much time by reading the full list.
-          break;
         }
       }
-
+      if (nextCleanupTaskDelay > 0) {
-      if (!calls.isEmpty()) {
+        cleanupTimer =
-        AsyncCall firstCall = calls.firstEntry().getValue();
+            client.newTimeout(timeoutTask, nextCleanupTaskDelay,
-
+              TimeUnit.MILLISECONDS);
-        final long newTimeout;
+      } else {
-        long maxWaitTime = EnvironmentEdgeManager.currentTime() - firstCall.getStartTime();
+        cleanupTimer = null;
-        if (maxWaitTime < firstCall.getRpcTimeout()) {
-          newTimeout = firstCall.getRpcTimeout() - maxWaitTime;
-        } else {
-          newTimeout = 0;
-        }
-
-        closeException = null;
-        cleanupTimer = AsyncRpcClient.WHEEL_TIMER.newTimeout(timeoutTask,
-            newTimeout, TimeUnit.MILLISECONDS);
       }
     }
+    for (AsyncCall call : toCleanup) {
+      call.setFailed(new CallTimeoutException("Call id=" + call.id + ", waitTime="
+          + (currentTime - call.getStartTime()) + ", rpcTimeout=" + call.getRpcTimeout()));
+    }
   }
 
   /**
@@ -745,6 +709,10 @@ public class AsyncRpcChannel {
     });
   }
 
+  public int getConnectionHashCode() {
+    return ConnectionId.hashCode(ticket, serviceName, address);
+  }
+
   @Override
   public String toString() {
     return this.address.toString() + "/" + this.serviceName + "/" + this.ticket;
@@ -755,20 +723,22 @@ public class AsyncRpcChannel {
    */
   private static final class CallWriteListener implements ChannelFutureListener {
     private final AsyncRpcChannel rpcChannel;
-    private final AsyncCall call;
+    private final int id;
 
-    public CallWriteListener(AsyncRpcChannel asyncRpcChannel, AsyncCall call) {
+    public CallWriteListener(AsyncRpcChannel asyncRpcChannel, int id) {
       this.rpcChannel = asyncRpcChannel;
-      this.call = call;
+      this.id = id;
     }
 
-    @Override public void operationComplete(ChannelFuture future) throws Exception {
+    @Override
+    public void operationComplete(ChannelFuture future) throws Exception {
       if (!future.isSuccess()) {
-        if(!this.call.isDone()) {
+        AsyncCall call = rpcChannel.removePendingCall(id);
+        if (call != null) {
           if (future.cause() instanceof IOException) {
-            rpcChannel.failCall(call, (IOException) future.cause());
+            call.setFailed((IOException) future.cause());
           } else {
-            rpcChannel.failCall(call, new IOException(future.cause()));
+            call.setFailed(new IOException(future.cause()));
           }
         }
       }

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AsyncRpcClient.java

@@ -17,14 +17,7 @@
  */
 package org.apache.hadoop.hbase.ipc;
 
-import com.google.common.annotations.VisibleForTesting;
-import com.google.protobuf.Descriptors;
-import com.google.protobuf.Message;
-import com.google.protobuf.RpcCallback;
-import com.google.protobuf.RpcChannel;
-import com.google.protobuf.RpcController;
 import io.netty.bootstrap.Bootstrap;
-import io.netty.buffer.PooledByteBufAllocator;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
@@ -35,11 +28,24 @@ import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.util.HashedWheelTimer;
+import io.netty.util.Timeout;
+import io.netty.util.TimerTask;
 import io.netty.util.concurrent.Future;
 import io.netty.util.concurrent.GenericFutureListener;
 import io.netty.util.concurrent.Promise;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.SocketAddress;
+import java.nio.ByteBuffer;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicInteger;
+
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.CellScanner;
+import org.apache.hadoop.hbase.HBaseInterfaceAudience;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
@@ -49,25 +55,26 @@ import org.apache.hadoop.hbase.util.Pair;
 import org.apache.hadoop.hbase.util.PoolMap;
 import org.apache.hadoop.hbase.util.Threads;
 
-import java.io.IOException;
+import com.google.common.annotations.VisibleForTesting;
-import java.net.InetSocketAddress;
+import com.google.protobuf.Descriptors;
-import java.net.SocketAddress;
+import com.google.protobuf.Message;
-import java.nio.ByteBuffer;
+import com.google.protobuf.RpcCallback;
-import java.util.concurrent.ExecutionException;
+import com.google.protobuf.RpcChannel;
-import java.util.concurrent.TimeUnit;
+import com.google.protobuf.RpcController;
-import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * Netty client for the requests and responses
  */
-@InterfaceAudience.Private
+@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
 public class AsyncRpcClient extends AbstractRpcClient {
 
   public static final String CLIENT_MAX_THREADS = "hbase.rpc.client.threads.max";
-  public static final String USE_NATIVE_TRANSPORT = "hbase.rpc.client.useNativeTransport";
+  public static final String USE_NATIVE_TRANSPORT = "hbase.rpc.client.nativetransport";
+  public static final String USE_GLOBAL_EVENT_LOOP_GROUP = "hbase.rpc.client.globaleventloopgroup";
 
-  public static final HashedWheelTimer WHEEL_TIMER =
+  private static final HashedWheelTimer WHEEL_TIMER =
-      new HashedWheelTimer(100, TimeUnit.MILLISECONDS);
+      new HashedWheelTimer(Threads.newDaemonThreadFactory("AsyncRpcChannel-timer"),
+          100, TimeUnit.MILLISECONDS);
 
   private static final ChannelInitializer<SocketChannel> DEFAULT_CHANNEL_INITIALIZER =
       new ChannelInitializer<SocketChannel>() {
@@ -79,12 +86,54 @@ public class AsyncRpcClient extends AbstractRpcClient {
 
   protected final AtomicInteger callIdCnt = new AtomicInteger();
 
-  private final EventLoopGroup eventLoopGroup;
   private final PoolMap<Integer, AsyncRpcChannel> connections;
 
   final FailedServers failedServers;
 
-  private final Bootstrap bootstrap;
+  @VisibleForTesting
+  final Bootstrap bootstrap;
+
+  private final boolean useGlobalEventLoopGroup;
+
+  @VisibleForTesting
+  static Pair<EventLoopGroup, Class<? extends Channel>> GLOBAL_EVENT_LOOP_GROUP;
+
+  private synchronized static Pair<EventLoopGroup, Class<? extends Channel>>
+      getGlobalEventLoopGroup(Configuration conf) {
+    if (GLOBAL_EVENT_LOOP_GROUP == null) {
+      GLOBAL_EVENT_LOOP_GROUP = createEventLoopGroup(conf);
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("Create global event loop group "
+            + GLOBAL_EVENT_LOOP_GROUP.getFirst().getClass().getSimpleName());
+      }
+    }
+    return GLOBAL_EVENT_LOOP_GROUP;
+  }
+
+  private static Pair<EventLoopGroup, Class<? extends Channel>> createEventLoopGroup(
+      Configuration conf) {
+    // Max amount of threads to use. 0 lets Netty decide based on amount of cores
+    int maxThreads = conf.getInt(CLIENT_MAX_THREADS, 0);
+
+    // Config to enable native transport. Does not seem to be stable at time of implementation
+    // although it is not extensively tested.
+    boolean epollEnabled = conf.getBoolean(USE_NATIVE_TRANSPORT, false);
+
+    // Use the faster native epoll transport mechanism on linux if enabled
+    if (epollEnabled && JVM.isLinux()) {
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("Create EpollEventLoopGroup with maxThreads = " + maxThreads);
+      }
+      return new Pair<EventLoopGroup, Class<? extends Channel>>(new EpollEventLoopGroup(maxThreads,
+          Threads.newDaemonThreadFactory("AsyncRpcChannel")), EpollSocketChannel.class);
+    } else {
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("Create NioEventLoopGroup with maxThreads = " + maxThreads);
+      }
+      return new Pair<EventLoopGroup, Class<? extends Channel>>(new NioEventLoopGroup(maxThreads,
+          Threads.newDaemonThreadFactory("AsyncRpcChannel")), NioSocketChannel.class);
+    }
+  }
 
   /**
    * Constructor for tests
@@ -103,23 +152,16 @@ public class AsyncRpcClient extends AbstractRpcClient {
       LOG.debug("Starting async Hbase RPC client");
     }
 
-    // Max amount of threads to use. 0 lets Netty decide based on amount of cores
+    Pair<EventLoopGroup, Class<? extends Channel>> eventLoopGroupAndChannelClass;
-    int maxThreads = conf.getInt(CLIENT_MAX_THREADS, 0);
+    this.useGlobalEventLoopGroup = conf.getBoolean(USE_GLOBAL_EVENT_LOOP_GROUP, true);
-
+    if (useGlobalEventLoopGroup) {
-    // Config to enable native transport. Does not seem to be stable at time of implementation
+      eventLoopGroupAndChannelClass = getGlobalEventLoopGroup(configuration);
-    // although it is not extensively tested.
-    boolean epollEnabled = conf.getBoolean(USE_NATIVE_TRANSPORT, false);
-
-    // Use the faster native epoll transport mechanism on linux if enabled
-    Class<? extends Channel> socketChannelClass;
-    if (epollEnabled && JVM.isLinux()) {
-      socketChannelClass = EpollSocketChannel.class;
-      this.eventLoopGroup =
-          new EpollEventLoopGroup(maxThreads, Threads.newDaemonThreadFactory("AsyncRpcChannel"));
     } else {
-      socketChannelClass = NioSocketChannel.class;
+      eventLoopGroupAndChannelClass = createEventLoopGroup(configuration);
-      this.eventLoopGroup =
+    }
-          new NioEventLoopGroup(maxThreads, Threads.newDaemonThreadFactory("AsyncRpcChannel"));
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("Use " + (useGlobalEventLoopGroup ? "global" : "individual") + " event loop group "
+          + eventLoopGroupAndChannelClass.getFirst().getClass().getSimpleName());
     }
 
     this.connections = new PoolMap<>(getPoolType(configuration), getPoolSize(configuration));
@@ -130,8 +172,8 @@ public class AsyncRpcClient extends AbstractRpcClient {
 
     // Configure the default bootstrap.
     this.bootstrap = new Bootstrap();
-    bootstrap.group(eventLoopGroup).channel(socketChannelClass)
+    bootstrap.group(eventLoopGroupAndChannelClass.getFirst())
-        .option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
+        .channel(eventLoopGroupAndChannelClass.getSecond())
         .option(ChannelOption.TCP_NODELAY, tcpNoDelay)
         .option(ChannelOption.SO_KEEPALIVE, tcpKeepAlive)
         .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, operationTimeout);
@@ -169,16 +211,19 @@ public class AsyncRpcClient extends AbstractRpcClient {
    * @throws InterruptedException if call is interrupted
    * @throws java.io.IOException  if a connection failure is encountered
    */
-  @Override protected Pair<Message, CellScanner> call(PayloadCarryingRpcController pcrc,
+  @Override
+  protected Pair<Message, CellScanner> call(PayloadCarryingRpcController pcrc,
       Descriptors.MethodDescriptor md, Message param, Message returnType, User ticket,
       InetSocketAddress addr) throws IOException, InterruptedException {
-
+    if (pcrc == null) {
+      pcrc = new PayloadCarryingRpcController();
+    }
     final AsyncRpcChannel connection = createRpcChannel(md.getService().getName(), addr, ticket);
 
-    Promise<Message> promise = connection.callMethodWithPromise(md, pcrc, param, returnType);
+    Promise<Message> promise = connection.callMethod(md, pcrc, param, returnType);
-
+    long timeout = pcrc.hasCallTimeout() ? pcrc.getCallTimeout() : 0;
     try {
-      Message response = promise.get();
+      Message response = timeout > 0 ? promise.get(timeout, TimeUnit.MILLISECONDS) : promise.get();
       return new Pair<>(response, pcrc.cellScanner());
     } catch (ExecutionException e) {
       if (e.getCause() instanceof IOException) {
@@ -186,6 +231,8 @@ public class AsyncRpcClient extends AbstractRpcClient {
       } else {
         throw new IOException(e.getCause());
       }
+    } catch (TimeoutException e) {
+      throw new CallTimeoutException(promise.toString());
     }
   }
 
@@ -231,6 +278,8 @@ public class AsyncRpcClient extends AbstractRpcClient {
     }
   }
 
+  private boolean closed = false;
+
   /**
    * Close netty
    */
@@ -240,12 +289,18 @@ public class AsyncRpcClient extends AbstractRpcClient {
     }
 
     synchronized (connections) {
+      if (closed) {
+        return;
+      }
+      closed = true;
       for (AsyncRpcChannel conn : connections.values()) {
         conn.close(null);
       }
     }
-
+    // do not close global EventLoopGroup.
-    eventLoopGroup.shutdownGracefully();
+    if (!useGlobalEventLoopGroup) {
+      bootstrap.group().shutdownGracefully();
+    }
   }
 
   /**
@@ -282,10 +337,6 @@ public class AsyncRpcClient extends AbstractRpcClient {
    */
   private AsyncRpcChannel createRpcChannel(String serviceName, InetSocketAddress location,
       User ticket) throws StoppedRpcClientException, FailedServerException {
-    if (this.eventLoopGroup.isShuttingDown() || this.eventLoopGroup.isShutdown()) {
-      throw new StoppedRpcClientException();
-    }
-
     // Check if server is failed
     if (this.failedServers.isFailedServer(location)) {
       if (LOG.isDebugEnabled()) {
@@ -300,6 +351,9 @@ public class AsyncRpcClient extends AbstractRpcClient {
 
     AsyncRpcChannel rpcChannel;
     synchronized (connections) {
+      if (closed) {
+        throw new StoppedRpcClientException();
+      }
       rpcChannel = connections.get(hashCode);
       if (rpcChannel == null) {
         rpcChannel = new AsyncRpcChannel(this.bootstrap, this, ticket, serviceName, location);
@@ -337,12 +391,20 @@ public class AsyncRpcClient extends AbstractRpcClient {
 
   /**
    * Remove connection from pool
-   *
-   * @param connectionHashCode of connection
    */
-  public void removeConnection(int connectionHashCode) {
+  public void removeConnection(AsyncRpcChannel connection) {
+    int connectionHashCode = connection.getConnectionHashCode();
     synchronized (connections) {
-      this.connections.remove(connectionHashCode);
+      // we use address as cache key, so we should check here to prevent removing the
+      // wrong connection
+      AsyncRpcChannel connectionInPool = this.connections.get(connectionHashCode);
+      if (connectionInPool == connection) {
+        this.connections.remove(connectionHashCode);
+      } else if (LOG.isDebugEnabled()) {
+        LOG.debug(String.format("%s already removed, expected instance %08x, actual %08x",
+          connection.toString(), System.identityHashCode(connection),
+          System.identityHashCode(connectionInPool)));
+      }
     }
   }
 
@@ -399,4 +461,8 @@ public class AsyncRpcClient extends AbstractRpcClient {
       this.rpcClient.callMethod(md, pcrc, param, returnType, this.ticket, this.isa, done);
     }
   }
-}
+
+  Timeout newTimeout(TimerTask task, long delay, TimeUnit unit) {
+    return WHEEL_TIMER.newTimeout(task, delay, unit);
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AsyncServerResponseHandler.java

@@ -17,11 +17,13 @@
  */
 package org.apache.hadoop.hbase.ipc;
 
-import com.google.protobuf.Message;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufInputStream;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
+
+import java.io.IOException;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.CellScanner;
@@ -30,7 +32,7 @@ import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.protobuf.generated.RPCProtos;
 import org.apache.hadoop.ipc.RemoteException;
 
-import java.io.IOException;
+import com.google.protobuf.Message;
 
 /**
  * Handles Hbase responses
@@ -53,16 +55,12 @@ public class AsyncServerResponseHandler extends ChannelInboundHandlerAdapter {
   @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
     ByteBuf inBuffer = (ByteBuf) msg;
     ByteBufInputStream in = new ByteBufInputStream(inBuffer);
-
-    if (channel.shouldCloseConnection) {
-      return;
-    }
     int totalSize = inBuffer.readableBytes();
     try {
       // Read the header
       RPCProtos.ResponseHeader responseHeader = RPCProtos.ResponseHeader.parseDelimitedFrom(in);
       int id = responseHeader.getCallId();
-      AsyncCall call = channel.calls.get(id);
+      AsyncCall call = channel.removePendingCall(id);
       if (call == null) {
         // So we got a response for which we have no corresponding 'call' here on the client-side.
         // We probably timed out waiting, cleaned up all references, and now the server decides
@@ -86,7 +84,7 @@ public class AsyncServerResponseHandler extends ChannelInboundHandlerAdapter {
             equals(FatalConnectionException.class.getName())) {
           channel.close(re);
         } else {
-          channel.failCall(call, re);
+          call.setFailed(re);
         }
       } else {
         Message value = null;
@@ -105,13 +103,11 @@ public class AsyncServerResponseHandler extends ChannelInboundHandlerAdapter {
         }
         call.setSuccess(value, cellBlockScanner);
       }
-      channel.calls.remove(id);
     } catch (IOException e) {
       // Treat this as a fatal condition and close this connection
       channel.close(e);
     } finally {
       inBuffer.release();
-      channel.cleanupCalls(false);
     }
   }
 

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/IPCUtil.java

@@ -33,6 +33,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.HBaseIOException;
 import org.apache.hadoop.hbase.codec.Codec;
+import org.apache.hadoop.hbase.io.BoundedByteBufferPool;
 import org.apache.hadoop.hbase.io.ByteBufferOutputStream;
 import org.apache.hadoop.hbase.io.HeapSize;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -65,6 +66,7 @@ public class IPCUtil {
     this.conf = conf;
     this.cellBlockDecompressionMultiplier =
         conf.getInt("hbase.ipc.cellblock.decompression.buffersize.multiplier", 3);
+
     // Guess that 16k is a good size for rpc buffer.  Could go bigger.  See the TODO below in
     // #buildCellBlock.
     this.cellBlockBuildingInitialBufferSize =
@@ -90,24 +92,49 @@ public class IPCUtil {
   @SuppressWarnings("resource")
   public ByteBuffer buildCellBlock(final Codec codec, final CompressionCodec compressor,
     final CellScanner cellScanner)
+  throws IOException {
+    return buildCellBlock(codec, compressor, cellScanner, null);
+  }
+
+  /**
+   * Puts CellScanner Cells into a cell block using passed in <code>codec</code> and/or
+   * <code>compressor</code>.
+   * @param codec
+   * @param compressor
+   * @param cellScanner
+   * @param pool Pool of ByteBuffers to make use of. Can be null and then we'll allocate
+   * our own ByteBuffer.
+   * @return Null or byte buffer filled with a cellblock filled with passed-in Cells encoded using
+   * passed in <code>codec</code> and/or <code>compressor</code>; the returned buffer has been
+   * flipped and is ready for reading.  Use limit to find total size. If <code>pool</code> was not
+   * null, then this returned ByteBuffer came from there and should be returned to the pool when
+   * done.
+   * @throws IOException
+   */
+  @SuppressWarnings("resource")
+  public ByteBuffer buildCellBlock(final Codec codec, final CompressionCodec compressor,
+    final CellScanner cellScanner, final BoundedByteBufferPool pool)
   throws IOException {
     if (cellScanner == null) return null;
     if (codec == null) throw new CellScannerButNoCodecException();
     int bufferSize = this.cellBlockBuildingInitialBufferSize;
-    if (cellScanner instanceof HeapSize) {
+    ByteBufferOutputStream baos = null;
-      long longSize = ((HeapSize)cellScanner).heapSize();
+    if (pool != null) {
-      // Just make sure we don't have a size bigger than an int.
+      ByteBuffer bb = pool.getBuffer();
-      if (longSize > Integer.MAX_VALUE) {
+      bufferSize = bb.capacity();
-        throw new IOException("Size " + longSize + " > " + Integer.MAX_VALUE);
+      baos = new ByteBufferOutputStream(bb);
+    } else {
+      // Then we need to make our own to return.
+      if (cellScanner instanceof HeapSize) {
+        long longSize = ((HeapSize)cellScanner).heapSize();
+        // Just make sure we don't have a size bigger than an int.
+        if (longSize > Integer.MAX_VALUE) {
+          throw new IOException("Size " + longSize + " > " + Integer.MAX_VALUE);
+        }
+        bufferSize = ClassSize.align((int)longSize);
       }
-      bufferSize = ClassSize.align((int)longSize);
+      baos = new ByteBufferOutputStream(bufferSize);
-    } // TODO: Else, get estimate on size of buffer rather than have the buffer resize.
+    }
-    // See TestIPCUtil main for experiment where we spin through the Cells getting estimate of
-    // total size before creating the buffer.  It costs somw small percentage.  If we are usually
-    // within the estimated buffer size, then the cost is not worth it.  If we are often well
-    // outside the guesstimated buffer size, the processing can be done in half the time if we
-    // go w/ the estimated size rather than let the buffer resize.
-    ByteBufferOutputStream baos = new ByteBufferOutputStream(bufferSize);
     OutputStream os = baos;
     Compressor poolCompressor = null;
     try {

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RpcClientImpl.java

@@ -263,7 +263,10 @@ public class RpcClientImpl extends AbstractRpcClient {
           try {
             Connection.this.tracedWriteRequest(cts.call, cts.priority, cts.span);
           } catch (IOException e) {
-            LOG.warn("call write error for call #" + cts.call.id + ", message =" + e.getMessage());
+            if (LOG.isDebugEnabled()) {
+              LOG.debug("call write error for call #" + cts.call.id
+                + ", message =" + e.getMessage());
+            }
             cts.call.setException(e);
             markClosed(e);
           }
@@ -355,6 +358,7 @@ public class RpcClientImpl extends AbstractRpcClient {
       if (this.compressor != null) {
         builder.setCellBlockCompressorClass(this.compressor.getClass().getCanonicalName());
       }
+      builder.setVersionInfo(ProtobufUtil.getVersionInfo());
       this.header = builder.build();
 
       this.setName("IPC Client (" + socketFactory.hashCode() +") connection to " +
@@ -1133,6 +1137,7 @@ public class RpcClientImpl extends AbstractRpcClient {
    * @throws InterruptedException
    * @throws IOException
    */
+  @Override
   protected Pair<Message, CellScanner> call(PayloadCarryingRpcController pcrc, MethodDescriptor md,
       Message param, Message returnType, User ticket, InetSocketAddress addr)
       throws IOException, InterruptedException {

hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java

@@ -40,7 +40,6 @@ import java.util.NavigableSet;
 import java.util.concurrent.TimeUnit;
 
 import com.google.protobuf.*;
-import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.Cell;
@@ -56,6 +55,7 @@ import org.apache.hadoop.hbase.NamespaceDescriptor;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.client.Append;
 import org.apache.hadoop.hbase.client.Consistency;
 import org.apache.hadoop.hbase.client.Delete;
@@ -71,7 +71,6 @@ import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.hadoop.hbase.filter.ByteArrayComparable;
 import org.apache.hadoop.hbase.filter.Filter;
 import org.apache.hadoop.hbase.io.TimeRange;
-import org.apache.hadoop.hbase.protobuf.ProtobufMagic;
 import org.apache.hadoop.hbase.protobuf.generated.AccessControlProtos;
 import org.apache.hadoop.hbase.protobuf.generated.AccessControlProtos.AccessControlService;
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.AdminService;
@@ -89,6 +88,7 @@ import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.MergeRegionsReques
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.OpenRegionRequest;
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.ServerInfo;
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.SplitRegionRequest;
+import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.WarmupRegionRequest;
 import org.apache.hadoop.hbase.protobuf.generated.AuthenticationProtos;
 import org.apache.hadoop.hbase.protobuf.generated.CellProtos;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
@@ -107,6 +107,7 @@ import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutationProto.Col
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutationProto.DeleteType;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutationProto.MutationType;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ScanRequest;
+import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos;
 import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos.RegionLoad;
 import org.apache.hadoop.hbase.protobuf.generated.ComparatorProtos;
 import org.apache.hadoop.hbase.protobuf.generated.FilterProtos;
@@ -120,6 +121,7 @@ import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.CreateTableReques
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetTableDescriptorsResponse;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.MasterService;
 import org.apache.hadoop.hbase.protobuf.generated.QuotaProtos;
+import org.apache.hadoop.hbase.protobuf.generated.RPCProtos;
 import org.apache.hadoop.hbase.protobuf.generated.RegionServerStatusProtos.RegionServerReportRequest;
 import org.apache.hadoop.hbase.protobuf.generated.RegionServerStatusProtos.RegionServerStartupRequest;
 import org.apache.hadoop.hbase.protobuf.generated.WALProtos;
@@ -133,6 +135,8 @@ import org.apache.hadoop.hbase.protobuf.generated.WALProtos.StoreDescriptor;
 import org.apache.hadoop.hbase.quotas.QuotaScope;
 import org.apache.hadoop.hbase.quotas.QuotaType;
 import org.apache.hadoop.hbase.quotas.ThrottleType;
+import org.apache.hadoop.hbase.replication.ReplicationLoadSink;
+import org.apache.hadoop.hbase.replication.ReplicationLoadSource;
 import org.apache.hadoop.hbase.security.access.Permission;
 import org.apache.hadoop.hbase.security.access.TablePermission;
 import org.apache.hadoop.hbase.security.access.UserPermission;
@@ -145,6 +149,7 @@ import org.apache.hadoop.hbase.util.DynamicClassLoader;
 import org.apache.hadoop.hbase.util.ExceptionUtil;
 import org.apache.hadoop.hbase.util.Methods;
 import org.apache.hadoop.hbase.util.Pair;
+import org.apache.hadoop.hbase.util.VersionInfo;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.ipc.RemoteException;
 import org.apache.hadoop.security.token.Token;
@@ -1277,6 +1282,7 @@ public final class ProtobufUtil {
     }
 
     builder.setStale(result.isStale());
+    builder.setPartial(result.isPartial());
 
     return builder.build();
   }
@@ -1335,7 +1341,7 @@ public final class ProtobufUtil {
     for (CellProtos.Cell c : values) {
       cells.add(toCell(c));
     }
-    return Result.create(cells, null, proto.getStale());
+    return Result.create(cells, null, proto.getStale(), proto.getPartial());
   }
 
   /**
@@ -1718,6 +1724,26 @@ public final class ProtobufUtil {
     }
   }
 
+  /**
+   * A helper to warmup a region given a region name
+   * using admin protocol
+   *
+   * @param admin
+   * @param regionInfo
+   *
+   */
+  public static void warmupRegion(final AdminService.BlockingInterface admin,
+      final HRegionInfo regionInfo) throws IOException  {
+
+    try {
+      WarmupRegionRequest warmupRegionRequest =
+           RequestConverter.buildWarmupRegionRequest(regionInfo);
+
+      admin.warmupRegion(null, warmupRegionRequest);
+    } catch (ServiceException e) {
+      throw getRemoteException(e);
+    }
+  }
 
   /**
    * A helper to open a region using admin protocol.
@@ -1736,6 +1762,7 @@ public final class ProtobufUtil {
     }
   }
 
+
   /**
    * A helper to get the all the online regions on a region
    * server using admin protocol.
@@ -2576,6 +2603,7 @@ public final class ProtobufUtil {
     FlushDescriptor.Builder desc = FlushDescriptor.newBuilder()
         .setAction(action)
         .setEncodedRegionName(ByteStringer.wrap(hri.getEncodedNameAsBytes()))
+        .setRegionName(ByteStringer.wrap(hri.getRegionName()))
         .setFlushSequenceNumber(flushSeqId)
         .setTableName(ByteStringer.wrap(hri.getTable().getName()));
 
@@ -2601,6 +2629,7 @@ public final class ProtobufUtil {
         .setEventType(eventType)
         .setTableName(ByteStringer.wrap(hri.getTable().getName()))
         .setEncodedRegionName(ByteStringer.wrap(hri.getEncodedNameAsBytes()))
+        .setRegionName(ByteStringer.wrap(hri.getRegionName()))
         .setLogSequenceNumber(seqId)
         .setServer(toServerName(server));
 
@@ -2991,7 +3020,6 @@ public final class ProtobufUtil {
   }
 
 
-
   /**
    * This version of protobuf's mergeDelimitedFrom avoid the hard-coded 64MB limit for decoding
    * buffers
@@ -3071,4 +3099,40 @@ public final class ProtobufUtil {
       return result;
     }
   }
+
+  public static ReplicationLoadSink toReplicationLoadSink(
+      ClusterStatusProtos.ReplicationLoadSink cls) {
+    return new ReplicationLoadSink(cls.getAgeOfLastAppliedOp(), cls.getTimeStampsOfLastAppliedOp());
+  }
+
+  public static ReplicationLoadSource toReplicationLoadSource(
+      ClusterStatusProtos.ReplicationLoadSource cls) {
+    return new ReplicationLoadSource(cls.getPeerID(), cls.getAgeOfLastShippedOp(),
+        cls.getSizeOfLogQueue(), cls.getTimeStampOfLastShippedOp(), cls.getReplicationLag());
+  }
+
+  public static List<ReplicationLoadSource> toReplicationLoadSourceList(
+      List<ClusterStatusProtos.ReplicationLoadSource> clsList) {
+    ArrayList<ReplicationLoadSource> rlsList = new ArrayList<ReplicationLoadSource>();
+    for (ClusterStatusProtos.ReplicationLoadSource cls : clsList) {
+      rlsList.add(toReplicationLoadSource(cls));
+    }
+    return rlsList;
+  }
+
+  /**
+   * Get a protocol buffer VersionInfo
+   *
+   * @return the converted protocol buffer VersionInfo
+   */
+  public static RPCProtos.VersionInfo getVersionInfo() {
+    RPCProtos.VersionInfo.Builder builder = RPCProtos.VersionInfo.newBuilder();
+    builder.setVersion(VersionInfo.getVersion());
+    builder.setUrl(VersionInfo.getUrl());
+    builder.setRevision(VersionInfo.getRevision());
+    builder.setUser(VersionInfo.getUser());
+    builder.setDate(VersionInfo.getDate());
+    builder.setSrcChecksum(VersionInfo.getSrcChecksum());
+    return builder.build();
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/RequestConverter.java

@@ -46,6 +46,7 @@ import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.hadoop.hbase.filter.ByteArrayComparable;
 import org.apache.hadoop.hbase.protobuf.generated.AccessControlProtos;
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.CloseRegionRequest;
+import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.WarmupRegionRequest;
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.CompactRegionRequest;
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.FlushRegionRequest;
 import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.GetOnlineRegionRequest;
@@ -91,6 +92,7 @@ import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetSchemaAlterSta
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetTableDescriptorsRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetTableNamesRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetTableStateRequest;
+import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsBalancerEnabledRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsCatalogJanitorEnabledRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsMasterRunningRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ModifyColumnRequest;
@@ -486,6 +488,7 @@ public final class RequestConverter {
     builder.setCloseScanner(closeScanner);
     builder.setRegion(region);
     builder.setScan(ProtobufUtil.toScan(scan));
+    builder.setClientHandlesPartials(true);
     return builder.build();
   }
 
@@ -503,6 +506,7 @@ public final class RequestConverter {
     builder.setNumberOfRows(numberOfRows);
     builder.setCloseScanner(closeScanner);
     builder.setScannerId(scannerId);
+    builder.setClientHandlesPartials(true);
     return builder.build();
   }
 
@@ -522,6 +526,7 @@ public final class RequestConverter {
     builder.setCloseScanner(closeScanner);
     builder.setScannerId(scannerId);
     builder.setNextCallSeq(nextCallSeq);
+    builder.setClientHandlesPartials(true);
     return builder.build();
   }
 
@@ -739,10 +744,22 @@ public final class RequestConverter {
   */
  public static FlushRegionRequest
      buildFlushRegionRequest(final byte[] regionName) {
+   return buildFlushRegionRequest(regionName, false);
+ }
+
+ /**
+  * Create a protocol buffer FlushRegionRequest for a given region name
+  *
+  * @param regionName the name of the region to get info
+  * @return a protocol buffer FlushRegionRequest
+  */
+ public static FlushRegionRequest
+     buildFlushRegionRequest(final byte[] regionName, boolean writeFlushWALMarker) {
    FlushRegionRequest.Builder builder = FlushRegionRequest.newBuilder();
    RegionSpecifier region = buildRegionSpecifier(
      RegionSpecifierType.REGION_NAME, regionName);
    builder.setRegion(region);
+   builder.setWriteFlushWalMarker(writeFlushWALMarker);
    return builder.build();
  }
 
@@ -834,6 +851,16 @@ public final class RequestConverter {
     return builder.build();
   }
 
+  /**
+   *  Create a WarmupRegionRequest for a given region name
+   *
+   *  @param regionInfo Region we are warming up
+   */
+  public static WarmupRegionRequest buildWarmupRegionRequest(final HRegionInfo regionInfo) {
+    WarmupRegionRequest.Builder builder = WarmupRegionRequest.newBuilder();
+    builder.setRegionInfo(HRegionInfo.convert(regionInfo));
+    return builder.build();
+  }
  /**
   * Create a CloseRegionRequest for a given encoded region name
   *
@@ -1313,6 +1340,15 @@ public final class RequestConverter {
     return SetBalancerRunningRequest.newBuilder().setOn(on).setSynchronous(synchronous).build();
   }
 
+  /**
+   * Creates a protocol buffer IsBalancerEnabledRequest
+   *
+   * @return a IsBalancerEnabledRequest
+   */
+  public static IsBalancerEnabledRequest buildIsBalancerEnabledRequest() {
+    return IsBalancerEnabledRequest.newBuilder().build();
+  }
+
   /**
    * @see {@link #buildGetClusterStatusRequest}
    */

hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ResponseConverter.java

@@ -44,6 +44,7 @@ import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.RegionAction;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.RegionActionResult;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ResultOrException;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ScanResponse;
+import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos.RegionStoreSequenceIds;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.NameBytesPair;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.EnableCatalogJanitorResponse;
@@ -300,8 +301,10 @@ public final class ResponseConverter {
    * @return A GetLastFlushedSequenceIdResponse
    */
   public static GetLastFlushedSequenceIdResponse buildGetLastFlushedSequenceIdResponse(
-      long seqId) {
+      RegionStoreSequenceIds ids) {
-    return GetLastFlushedSequenceIdResponse.newBuilder().setLastFlushedSequenceId(seqId).build();
+    return GetLastFlushedSequenceIdResponse.newBuilder()
+        .setLastFlushedSequenceId(ids.getLastFlushedSequenceId())
+        .addAllStoreLastFlushedSequenceId(ids.getStoreSequenceIdList()).build();
   }
 
   /**
@@ -339,6 +342,9 @@ public final class ResponseConverter {
         // Cells are out in cellblocks.  Group them up again as Results.  How many to read at a
         // time will be found in getCellsLength -- length here is how many Cells in the i'th Result
         int noOfCells = response.getCellsPerResult(i);
+        boolean isPartial =
+            response.getPartialFlagPerResultCount() > i ?
+                response.getPartialFlagPerResult(i) : false;
         List<Cell> cells = new ArrayList<Cell>(noOfCells);
         for (int j = 0; j < noOfCells; j++) {
           try {
@@ -361,7 +367,7 @@ public final class ResponseConverter {
           }
           cells.add(cellScanner.current());
         }
-        results[i] = Result.create(cells, null, response.getStale());
+        results[i] = Result.create(cells, null, response.getStale(), isPartial);
       } else {
         // Result is pure pb.
         results[i] = ProtobufUtil.toResult(response.getResults(i));

hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/package.html

@@ -20,7 +20,7 @@
 
 <head />
 <body bgcolor="white">
-Holds classes generated from <a href="http://code.google.com/apis/protocolbuffers/">protobuf</a>
+Holds classes generated from <a href="https://developers.google.com/protocol-buffers/">protobuf</a>
 <code>src/main/protobuf</code> definition files.
 
 <p>See under <code>src/main/protobuf</code> for instruction on how to generate the content under

hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/ThrottlingException.java

@@ -21,8 +21,6 @@ package org.apache.hadoop.hbase.quotas;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 
@@ -38,12 +36,11 @@ import org.apache.hadoop.hbase.classification.InterfaceStability;
 public class ThrottlingException extends QuotaExceededException {
   private static final long serialVersionUID = 1406576492085155743L;
 
-  private static final Log LOG = LogFactory.getLog(ThrottlingException.class);
-
   @InterfaceAudience.Public
   @InterfaceStability.Evolving
   public enum Type {
     NumRequestsExceeded,
+    RequestSizeExceeded,
     NumReadRequestsExceeded,
     NumWriteRequestsExceeded,
     WriteSizeExceeded,
@@ -52,6 +49,7 @@ public class ThrottlingException extends QuotaExceededException {
 
   private static final String[] MSG_TYPE = new String[] {
     "number of requests exceeded",
+    "request size limit exceeded",
     "number of read requests exceeded",
     "number of write requests exceeded",
     "write size limit exceeded",
@@ -98,6 +96,11 @@ public class ThrottlingException extends QuotaExceededException {
     throwThrottlingException(Type.NumRequestsExceeded, waitInterval);
   }
 
+  public static void throwRequestSizeExceeded(final long waitInterval)
+      throws ThrottlingException {
+    throwThrottlingException(Type.RequestSizeExceeded, waitInterval);
+  }
+
   public static void throwNumReadRequestsExceeded(final long waitInterval)
       throws ThrottlingException {
     throwThrottlingException(Type.NumReadRequestsExceeded, waitInterval);

hbase-client/src/main/java/org/apache/hadoop/hbase/replication/ReplicationLoadSink.java

@@ -0,0 +1,36 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
+ * agreements. See the NOTICE file distributed with this work for additional information regarding
+ * copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License. You may obtain a
+ * copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable
+ * law or agreed to in writing, software distributed under the License is distributed on an "AS IS"
+ * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License
+ * for the specific language governing permissions and limitations under the License.
+ */
+package org.apache.hadoop.hbase.replication;
+
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+
+/**
+ * A HBase ReplicationLoad to present MetricsSink information
+ */
+@InterfaceAudience.Private
+public class ReplicationLoadSink {
+  private long ageOfLastAppliedOp;
+  private long timeStampsOfLastAppliedOp;
+
+  public ReplicationLoadSink(long age, long timeStamp) {
+    this.ageOfLastAppliedOp = age;
+    this.timeStampsOfLastAppliedOp = timeStamp;
+  }
+
+  public long getAgeOfLastAppliedOp() {
+    return this.ageOfLastAppliedOp;
+  }
+
+  public long getTimeStampsOfLastAppliedOp() {
+    return this.timeStampsOfLastAppliedOp;
+  }
+
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/replication/ReplicationLoadSource.java

@@ -0,0 +1,53 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
+ * agreements. See the NOTICE file distributed with this work for additional information regarding
+ * copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License. You may obtain a
+ * copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable
+ * law or agreed to in writing, software distributed under the License is distributed on an "AS IS"
+ * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License
+ * for the specific language governing permissions and limitations under the License.
+ */
+package org.apache.hadoop.hbase.replication;
+
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+
+/**
+ * A HBase ReplicationLoad to present MetricsSource information
+ */
+@InterfaceAudience.Private
+public class ReplicationLoadSource {
+  private String peerID;
+  private long ageOfLastShippedOp;
+  private int sizeOfLogQueue;
+  private long timeStampOfLastShippedOp;
+  private long replicationLag;
+
+  public ReplicationLoadSource(String id, long age, int size, long timeStamp, long lag) {
+    this.peerID = id;
+    this.ageOfLastShippedOp = age;
+    this.sizeOfLogQueue = size;
+    this.timeStampOfLastShippedOp = timeStamp;
+    this.replicationLag = lag;
+  }
+
+  public String getPeerID() {
+    return this.peerID;
+  }
+
+  public long getAgeOfLastShippedOp() {
+    return this.ageOfLastShippedOp;
+  }
+
+  public long getSizeOfLogQueue() {
+    return this.sizeOfLogQueue;
+  }
+
+  public long getTimeStampOfLastShippedOp() {
+    return this.timeStampOfLastShippedOp;
+  }
+
+  public long getReplicationLag() {
+    return this.replicationLag;
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/security/EncryptionUtil.java

@@ -63,8 +63,7 @@ public class EncryptionUtil {
 
   /**
    * Protect a key by encrypting it with the secret key of the given subject.
-   * The configuration must be set up correctly for key alias resolution. Keys
+   * The configuration must be set up correctly for key alias resolution.
-   * are always wrapped using AES.
    * @param conf configuration
    * @param subject subject key alias
    * @param key the key
@@ -72,10 +71,12 @@ public class EncryptionUtil {
    */
   public static byte[] wrapKey(Configuration conf, String subject, Key key)
       throws IOException {
-    // Wrap the key with AES
+    // Wrap the key with the configured encryption algorithm.
-    Cipher cipher = Encryption.getCipher(conf, "AES");
+    String algorithm =
+        conf.get(HConstants.CRYPTO_KEY_ALGORITHM_CONF_KEY, HConstants.CIPHER_AES);
+    Cipher cipher = Encryption.getCipher(conf, algorithm);
     if (cipher == null) {
-      throw new RuntimeException("Cipher 'AES' not available");
+      throw new RuntimeException("Cipher '" + algorithm + "' not available");
     }
     EncryptionProtos.WrappedKey.Builder builder = EncryptionProtos.WrappedKey.newBuilder();
     builder.setAlgorithm(key.getAlgorithm());
@@ -100,8 +101,7 @@ public class EncryptionUtil {
 
   /**
    * Unwrap a key by decrypting it with the secret key of the given subject.
-   * The configuration must be set up correctly for key alias resolution. Keys
+   * The configuration must be set up correctly for key alias resolution.
-   * are always unwrapped using AES.
    * @param conf configuration
    * @param subject subject key alias
    * @param value the encrypted key bytes
@@ -113,10 +113,17 @@ public class EncryptionUtil {
       throws IOException, KeyException {
     EncryptionProtos.WrappedKey wrappedKey = EncryptionProtos.WrappedKey.PARSER
         .parseDelimitedFrom(new ByteArrayInputStream(value));
-    Cipher cipher = Encryption.getCipher(conf, "AES");
+    String algorithm = conf.get(HConstants.CRYPTO_KEY_ALGORITHM_CONF_KEY,
+      HConstants.CIPHER_AES);
+    Cipher cipher = Encryption.getCipher(conf, algorithm);
     if (cipher == null) {
-      throw new RuntimeException("Algorithm 'AES' not available");
+      throw new RuntimeException("Cipher '" + algorithm + "' not available");
     }
+    return getUnwrapKey(conf, subject, wrappedKey, cipher);
+  }
+
+  private static Key getUnwrapKey(Configuration conf, String subject,
+      EncryptionProtos.WrappedKey wrappedKey, Cipher cipher) throws IOException, KeyException {
     ByteArrayOutputStream out = new ByteArrayOutputStream();
     byte[] iv = wrappedKey.hasIv() ? wrappedKey.getIv().toByteArray() : null;
     Encryption.decryptWithSubjectKey(out, wrappedKey.getData().newInput(),
@@ -130,4 +137,26 @@ public class EncryptionUtil {
     return new SecretKeySpec(keyBytes, wrappedKey.getAlgorithm());
   }
 
+  /**
+   * Unwrap a wal key by decrypting it with the secret key of the given subject. The configuration
+   * must be set up correctly for key alias resolution.
+   * @param conf configuration
+   * @param subject subject key alias
+   * @param value the encrypted key bytes
+   * @return the raw key bytes
+   * @throws IOException if key is not found for the subject, or if some I/O error occurs
+   * @throws KeyException if fail to unwrap the key
+   */
+  public static Key unwrapWALKey(Configuration conf, String subject, byte[] value)
+      throws IOException, KeyException {
+    EncryptionProtos.WrappedKey wrappedKey =
+        EncryptionProtos.WrappedKey.PARSER.parseDelimitedFrom(new ByteArrayInputStream(value));
+    String algorithm = conf.get(HConstants.CRYPTO_WAL_ALGORITHM_CONF_KEY, HConstants.CIPHER_AES);
+    Cipher cipher = Encryption.getCipher(conf, algorithm);
+    if (cipher == null) {
+      throw new RuntimeException("Cipher '" + algorithm + "' not available");
+    }
+    return getUnwrapKey(conf, subject, wrappedKey, cipher);
+  }
+
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/security/SaslClientHandler.java

@@ -24,10 +24,12 @@ import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.ipc.RemoteException;
+import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.security.token.TokenIdentifier;
 
@@ -35,8 +37,10 @@ import javax.security.auth.callback.CallbackHandler;
 import javax.security.sasl.Sasl;
 import javax.security.sasl.SaslClient;
 import javax.security.sasl.SaslException;
+
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.security.PrivilegedExceptionAction;
 import java.util.Random;
 
 /**
@@ -48,6 +52,8 @@ public class SaslClientHandler extends ChannelDuplexHandler {
 
   private final boolean fallbackAllowed;
 
+  private final UserGroupInformation ticket;
+
   /**
    * Used for client or server's token to send or receive from each other.
    */
@@ -63,6 +69,7 @@ public class SaslClientHandler extends ChannelDuplexHandler {
   /**
    * Constructor
    *
+   * @param ticket                   the ugi
    * @param method                   auth method
    * @param token                    for Sasl
    * @param serverPrincipal          Server's Kerberos principal name
@@ -72,10 +79,11 @@ public class SaslClientHandler extends ChannelDuplexHandler {
    * @param successfulConnectHandler handler for succesful connects
    * @throws java.io.IOException if handler could not be created
    */
-  public SaslClientHandler(AuthMethod method, Token<? extends TokenIdentifier> token,
+  public SaslClientHandler(UserGroupInformation ticket, AuthMethod method,
-      String serverPrincipal, boolean fallbackAllowed, String rpcProtection,
+      Token<? extends TokenIdentifier> token, String serverPrincipal, boolean fallbackAllowed,
-      SaslExceptionHandler exceptionHandler, SaslSuccessfulConnectHandler successfulConnectHandler)
+      String rpcProtection, SaslExceptionHandler exceptionHandler,
-      throws IOException {
+      SaslSuccessfulConnectHandler successfulConnectHandler) throws IOException {
+    this.ticket = ticket;
     this.fallbackAllowed = fallbackAllowed;
 
     this.exceptionHandler = exceptionHandler;
@@ -109,8 +117,9 @@ public class SaslClientHandler extends ChannelDuplexHandler {
     default:
       throw new IOException("Unknown authentication method " + method);
     }
-    if (saslClient == null)
+    if (saslClient == null) {
       throw new IOException("Unable to find SASL client implementation");
+    }
   }
 
   /**
@@ -144,14 +153,26 @@ public class SaslClientHandler extends ChannelDuplexHandler {
             null);
   }
 
-  @Override public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
+  @Override
+  public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
     saslClient.dispose();
   }
 
-  @Override public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
+  private byte[] evaluateChallenge(final byte[] challenge) throws Exception {
-    this.saslToken = new byte[0];
+    return ticket.doAs(new PrivilegedExceptionAction<byte[]>() {
+
+      @Override
+      public byte[] run() throws Exception {
+        return saslClient.evaluateChallenge(challenge);
+      }
+    });
+  }
+
+  @Override
+  public void handlerAdded(final ChannelHandlerContext ctx) throws Exception {
+    saslToken = new byte[0];
     if (saslClient.hasInitialResponse()) {
-      saslToken = saslClient.evaluateChallenge(saslToken);
+      saslToken = evaluateChallenge(saslToken);
     }
     if (saslToken != null) {
       writeSaslToken(ctx, saslToken);
@@ -161,7 +182,8 @@ public class SaslClientHandler extends ChannelDuplexHandler {
     }
   }
 
-  @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+  @Override
+  public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
     ByteBuf in = (ByteBuf) msg;
 
     // If not complete, try to negotiate
@@ -187,15 +209,17 @@ public class SaslClientHandler extends ChannelDuplexHandler {
           }
         }
         saslToken = new byte[len];
-        if (LOG.isDebugEnabled())
+        if (LOG.isDebugEnabled()) {
           LOG.debug("Will read input token of size " + saslToken.length
               + " for processing by initSASLContext");
+        }
         in.readBytes(saslToken);
 
-        saslToken = saslClient.evaluateChallenge(saslToken);
+        saslToken = evaluateChallenge(saslToken);
         if (saslToken != null) {
-          if (LOG.isDebugEnabled())
+          if (LOG.isDebugEnabled()) {
             LOG.debug("Will send token of size " + saslToken.length + " from initSASLContext.");
+          }
           writeSaslToken(ctx, saslToken);
         }
       }
@@ -246,8 +270,7 @@ public class SaslClientHandler extends ChannelDuplexHandler {
 
   /**
    * Write SASL token
-   *
+   * @param ctx to write to
-   * @param ctx       to write to
    * @param saslToken to write
    */
   private void writeSaslToken(final ChannelHandlerContext ctx, byte[] saslToken) {
@@ -255,7 +278,8 @@ public class SaslClientHandler extends ChannelDuplexHandler {
     b.writeInt(saslToken.length);
     b.writeBytes(saslToken, 0, saslToken.length);
     ctx.writeAndFlush(b).addListener(new ChannelFutureListener() {
-      @Override public void operationComplete(ChannelFuture future) throws Exception {
+      @Override
+      public void operationComplete(ChannelFuture future) throws Exception {
         if (!future.isSuccess()) {
           exceptionCaught(ctx, future.cause());
         }
@@ -289,7 +313,8 @@ public class SaslClientHandler extends ChannelDuplexHandler {
     exceptionHandler.handle(this.retryCount++, this.random, cause);
   }
 
-  @Override public void write(final ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
+  @Override
+  public void write(final ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
       throws Exception {
     // If not complete, try to negotiate
     if (!saslClient.isComplete()) {

hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlClient.java

@@ -22,7 +22,6 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Pattern;
 
-import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.MasterNotRunningException;
@@ -33,7 +32,6 @@ import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
-import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.hbase.client.Table;
 import org.apache.hadoop.hbase.ipc.CoprocessorRpcChannel;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
@@ -60,7 +58,7 @@ public class AccessControlClient {
 
   /**
    * Grants permission on the specified table for the specified user
-   * @param conf
+   * @param connection The Connection instance to use
    * @param tableName
    * @param userName
    * @param family
@@ -68,66 +66,51 @@ public class AccessControlClient {
    * @param actions
    * @throws Throwable
    */
-  public static void grant(Configuration conf, final TableName tableName,
+  public static void grant(Connection connection, final TableName tableName,
       final String userName, final byte[] family, final byte[] qual,
       final Permission.Action... actions) throws Throwable {
-    // TODO: Make it so caller passes in a Connection rather than have us do this expensive
+    try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-    // setup each time.  This class only used in test and shell at moment though.
+      ProtobufUtil.grant(getAccessControlServiceStub(table), userName, tableName, family, qual,
-    try (Connection connection = ConnectionFactory.createConnection(conf)) {
-      try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-        ProtobufUtil.grant(getAccessControlServiceStub(table), userName, tableName, family, qual,
           actions);
-      }
     }
   }
 
   /**
    * Grants permission on the specified namespace for the specified user.
-   * @param conf
+   * @param connection The Connection instance to use
    * @param namespace
    * @param userName
    * @param actions
    * @throws Throwable
    */
-  public static void grant(Configuration conf, final String namespace,
+  public static void grant(Connection connection, final String namespace,
       final String userName, final Permission.Action... actions) throws Throwable {
-    // TODO: Make it so caller passes in a Connection rather than have us do this expensive
+    try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-    // setup each time.  This class only used in test and shell at moment though.
+      ProtobufUtil.grant(getAccessControlServiceStub(table), userName, namespace, actions);
-    try (Connection connection = ConnectionFactory.createConnection(conf)) {
-      try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-        ProtobufUtil.grant(getAccessControlServiceStub(table), userName, namespace, actions);
-      }
     }
   }
 
   /**
+   * @param connection The Connection instance to use
    * Grant global permissions for the specified user.
    */
-  public static void grant(Configuration conf, final String userName,
+  public static void grant(Connection connection, final String userName,
        final Permission.Action... actions) throws Throwable {
-    // TODO: Make it so caller passes in a Connection rather than have us do this expensive
+    try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-    // setup each time.  This class only used in test and shell at moment though.
+      ProtobufUtil.grant(getAccessControlServiceStub(table), userName, actions);
-    try (Connection connection = ConnectionFactory.createConnection(conf)) {
-      try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-        ProtobufUtil.grant(getAccessControlServiceStub(table), userName, actions);
-      }
     }
   }
 
-  public static boolean isAccessControllerRunning(Configuration conf)
+  public static boolean isAccessControllerRunning(Connection connection)
       throws MasterNotRunningException, ZooKeeperConnectionException, IOException {
-    // TODO: Make it so caller passes in a Connection rather than have us do this expensive
+    try (Admin admin = connection.getAdmin()) {
-    // setup each time.  This class only used in test and shell at moment though.
+      return admin.isTableAvailable(ACL_TABLE_NAME);
-    try (Connection connection = ConnectionFactory.createConnection(conf)) {
-      try (Admin admin = connection.getAdmin()) {
-        return admin.isTableAvailable(ACL_TABLE_NAME);
-      }
     }
   }
 
   /**
    * Revokes the permission on the table
-   * @param conf
+   * @param connection The Connection instance to use
    * @param tableName
    * @param username
    * @param family
@@ -135,81 +118,67 @@ public class AccessControlClient {
    * @param actions
    * @throws Throwable
    */
-  public static void revoke(Configuration conf, final TableName tableName,
+  public static void revoke(Connection connection, final TableName tableName,
       final String username, final byte[] family, final byte[] qualifier,
       final Permission.Action... actions) throws Throwable {
-    // TODO: Make it so caller passes in a Connection rather than have us do this expensive
+    try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-    // setup each time.  This class only used in test and shell at moment though.
+      ProtobufUtil.revoke(getAccessControlServiceStub(table), username, tableName, family,
-    try (Connection connection = ConnectionFactory.createConnection(conf)) {
-      try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-        ProtobufUtil.revoke(getAccessControlServiceStub(table), username, tableName, family,
           qualifier, actions);
-      }
     }
   }
 
   /**
    * Revokes the permission on the table for the specified user.
-   * @param conf
+   * @param connection The Connection instance to use
    * @param namespace
    * @param userName
    * @param actions
    * @throws Throwable
    */
-  public static void revoke(Configuration conf, final String namespace,
+  public static void revoke(Connection connection, final String namespace,
-    final String userName, final Permission.Action... actions) throws Throwable {
+      final String userName, final Permission.Action... actions) throws Throwable {
-    // TODO: Make it so caller passes in a Connection rather than have us do this expensive
+    try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-    // setup each time.  This class only used in test and shell at moment though.
+      ProtobufUtil.revoke(getAccessControlServiceStub(table), userName, namespace, actions);
-    try (Connection connection = ConnectionFactory.createConnection(conf)) {
-      try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-        ProtobufUtil.revoke(getAccessControlServiceStub(table), userName, namespace, actions);
-      }
     }
   }
 
   /**
    * Revoke global permissions for the specified user.
+   * @param connection The Connection instance to use
    */
-  public static void revoke(Configuration conf, final String userName,
+  public static void revoke(Connection connection, final String userName,
       final Permission.Action... actions) throws Throwable {
-    // TODO: Make it so caller passes in a Connection rather than have us do this expensive
+    try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-    // setup each time.  This class only used in test and shell at moment though.
+      ProtobufUtil.revoke(getAccessControlServiceStub(table), userName, actions);
-    try (Connection connection = ConnectionFactory.createConnection(conf)) {
-      try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-        ProtobufUtil.revoke(getAccessControlServiceStub(table), userName, actions);
-      }
     }
+
   }
 
   /**
    * List all the userPermissions matching the given pattern.
-   * @param conf
+   * @param connection The Connection instance to use
    * @param tableRegex The regular expression string to match against
    * @return - returns an array of UserPermissions
    * @throws Throwable
    */
-  public static List<UserPermission> getUserPermissions(Configuration conf, String tableRegex)
+  public static List<UserPermission> getUserPermissions(Connection connection, String tableRegex)
       throws Throwable {
     List<UserPermission> permList = new ArrayList<UserPermission>();
-    // TODO: Make it so caller passes in a Connection rather than have us do this expensive
+    try (Table table = connection.getTable(ACL_TABLE_NAME)) {
-    // setup each time.  This class only used in test and shell at moment though.
+      try (Admin admin = connection.getAdmin()) {
-    try (Connection connection = ConnectionFactory.createConnection(conf)) {
+        CoprocessorRpcChannel service = table.coprocessorService(HConstants.EMPTY_START_ROW);
-      try (Table table = connection.getTable(ACL_TABLE_NAME)) {
+        BlockingInterface protocol =
-        try (Admin admin = connection.getAdmin()) {
-          CoprocessorRpcChannel service = table.coprocessorService(HConstants.EMPTY_START_ROW);
-          BlockingInterface protocol =
             AccessControlProtos.AccessControlService.newBlockingStub(service);
-          HTableDescriptor[] htds = null;
+        HTableDescriptor[] htds = null;
-          if (tableRegex == null || tableRegex.isEmpty()) {
+        if (tableRegex == null || tableRegex.isEmpty()) {
-            permList = ProtobufUtil.getUserPermissions(protocol);
+          permList = ProtobufUtil.getUserPermissions(protocol);
-          } else if (tableRegex.charAt(0) == '@') {
+        } else if (tableRegex.charAt(0) == '@') {
-            String namespace = tableRegex.substring(1);
+          String namespace = tableRegex.substring(1);
-            permList = ProtobufUtil.getUserPermissions(protocol, Bytes.toBytes(namespace));
+          permList = ProtobufUtil.getUserPermissions(protocol, Bytes.toBytes(namespace));
-          } else {
+        } else {
-            htds = admin.listTables(Pattern.compile(tableRegex), true);
+          htds = admin.listTables(Pattern.compile(tableRegex), true);
-            for (HTableDescriptor hd : htds) {
+          for (HTableDescriptor hd : htds) {
-              permList.addAll(ProtobufUtil.getUserPermissions(protocol, hd.getTableName()));
+            permList.addAll(ProtobufUtil.getUserPermissions(protocol, hd.getTableName()));
-            }
           }
         }
       }

hbase-client/src/main/java/org/apache/hadoop/hbase/snapshot/SnapshotExistsException.java

@@ -28,6 +28,9 @@ import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescriptio
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
 public class SnapshotExistsException extends HBaseSnapshotException {
+  public SnapshotExistsException(String msg) {
+    super(msg);
+  }
 
   /**
    * Failure due to the snapshot already existing

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKConfig.java

@@ -33,6 +33,11 @@ import org.apache.hadoop.hbase.classification.InterfaceAudience;
 
 /**
  * Utility methods for reading, and building the ZooKeeper configuration.
+ *
+ * The order and priority for reading the config are as follows:
+ * (1). zoo.cfg if ""hbase.config.read.zookeeper.config" is true
+ * (2). Property with "hbase.zookeeper.property." prefix from HBase XML
+ * (3). other zookeeper related properties in HBASE XML
  */
 @InterfaceAudience.Private
 public class ZKConfig {
@@ -51,6 +56,24 @@ public class ZKConfig {
    * @return Properties holding mappings representing ZooKeeper config file.
    */
   public static Properties makeZKProps(Configuration conf) {
+    Properties zkProperties = makeZKPropsFromZooCfg(conf);
+
+    if (zkProperties == null) {
+      // Otherwise, use the configuration options from HBase's XML files.
+      zkProperties = makeZKPropsFromHbaseConfig(conf);
+    }
+    return zkProperties;
+  }
+
+  /**
+   * Parses the corresponding config options from the zoo.cfg file
+   * and make a Properties object holding the Zookeeper config.
+   *
+   * @param conf Configuration to read from.
+   * @return Properties holding mappings representing the ZooKeeper config file or null if
+   * the HBASE_CONFIG_READ_ZOOKEEPER_CONFIG is false or the file does not exist.
+   */
+  private static Properties makeZKPropsFromZooCfg(Configuration conf) {
     if (conf.getBoolean(HConstants.HBASE_CONFIG_READ_ZOOKEEPER_CONFIG, false)) {
       LOG.warn(
           "Parsing ZooKeeper's " + HConstants.ZOOKEEPER_CONFIG_NAME +
@@ -80,7 +103,18 @@ public class ZKConfig {
       }
     }
 
-    // Otherwise, use the configuration options from HBase's XML files.
+    return null;
+  }
+
+  /**
+   * Make a Properties object holding ZooKeeper config.
+   * Parses the corresponding config options from the HBase XML configs
+   * and generates the appropriate ZooKeeper properties.
+   *
+   * @param conf Configuration to read from.
+   * @return Properties holding mappings representing ZooKeeper config file.
+   */
+  private static Properties makeZKPropsFromHbaseConfig(Configuration conf) {
     Properties zkProperties = new Properties();
 
     // Directly map all of the hbase.zookeeper.property.KEY properties.
@@ -112,10 +146,17 @@ public class ZKConfig {
 
     final String[] serverHosts = conf.getStrings(HConstants.ZOOKEEPER_QUORUM,
                                                  HConstants.LOCALHOST);
+    String serverHost;
+    String address;
+    String key;
     for (int i = 0; i < serverHosts.length; ++i) {
-      String serverHost = serverHosts[i];
+      if (serverHosts[i].contains(":")) {
-      String address = serverHost + ":" + peerPort + ":" + leaderPort;
+        serverHost = serverHosts[i].substring(0, serverHosts[i].indexOf(':'));
-      String key = "server." + i;
+      } else {
+        serverHost = serverHosts[i];
+      }
+      address = serverHost + ":" + peerPort + ":" + leaderPort;
+      key = "server." + i;
       zkProperties.put(key, address);
     }
 
@@ -177,7 +218,8 @@ public class ZKConfig {
       }
       // Special case for 'hbase.cluster.distributed' property being 'true'
       if (key.startsWith("server.")) {
-        boolean mode = conf.getBoolean(HConstants.CLUSTER_DISTRIBUTED, HConstants.DEFAULT_CLUSTER_DISTRIBUTED);
+        boolean mode =
+            conf.getBoolean(HConstants.CLUSTER_DISTRIBUTED, HConstants.DEFAULT_CLUSTER_DISTRIBUTED);
         if (mode == HConstants.CLUSTER_IS_DISTRIBUTED && value.startsWith(HConstants.LOCALHOST)) {
           String msg = "The server in zoo.cfg cannot be set to localhost " +
               "in a fully-distributed setup because it won't be reachable. " +
@@ -198,7 +240,7 @@ public class ZKConfig {
    * @param properties
    * @return Quorum servers String
    */
-  public static String getZKQuorumServersString(Properties properties) {
+  private static String getZKQuorumServersString(Properties properties) {
     String clientPort = null;
     List<String> servers = new ArrayList<String>();
 
@@ -250,12 +292,59 @@ public class ZKConfig {
     return hostPortBuilder.toString();
   }
 
+  /**
+   * Return the ZK Quorum servers string given the specified configuration
+   *
+   * @param conf
+   * @return Quorum servers String
+   */
+  private static String getZKQuorumServersStringFromHbaseConfig(Configuration conf) {
+    String defaultClientPort = Integer.toString(
+        conf.getInt(HConstants.ZOOKEEPER_CLIENT_PORT, HConstants.DEFAULT_ZOOKEPER_CLIENT_PORT));
+
+    // Build the ZK quorum server string with "server:clientport" list, separated by ','
+    final String[] serverHosts =
+        conf.getStrings(HConstants.ZOOKEEPER_QUORUM, HConstants.LOCALHOST);
+    return buildQuorumServerString(serverHosts, defaultClientPort);
+  }
+
+  /**
+   * Build the ZK quorum server string with "server:clientport" list, separated by ','
+   *
+   * @param serverHosts a list of servers for ZK quorum
+   * @param clientPort the default client port
+   * @return the string for a list of "server:port" separated by ","
+   */
+  public static String buildQuorumServerString(String[] serverHosts, String clientPort) {
+    StringBuilder quorumStringBuilder = new StringBuilder();
+    String serverHost;
+    for (int i = 0; i < serverHosts.length; ++i) {
+      if (serverHosts[i].contains(":")) {
+        serverHost = serverHosts[i]; // just use the port specified from the input
+      } else {
+        serverHost = serverHosts[i] + ":" + clientPort;
+      }
+      if (i > 0) {
+        quorumStringBuilder.append(',');
+      }
+      quorumStringBuilder.append(serverHost);
+    }
+    return quorumStringBuilder.toString();
+  }
+
   /**
    * Return the ZK Quorum servers string given the specified configuration.
    * @param conf
    * @return Quorum servers
    */
   public static String getZKQuorumServersString(Configuration conf) {
-    return getZKQuorumServersString(makeZKProps(conf));
+    // First try zoo.cfg; if not applicable, then try config XML.
+    Properties zkProperties = makeZKPropsFromZooCfg(conf);
+
+    if (zkProperties != null) {
+      return getZKQuorumServersString(zkProperties);
+    }
+
+    return getZKQuorumServersStringFromHbaseConfig(conf);
   }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java

@@ -31,7 +31,6 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Properties;
 
 import javax.security.auth.login.AppConfigurationEntry;
 import javax.security.auth.login.AppConfigurationEntry.LoginModuleControlFlag;
@@ -46,8 +45,9 @@ import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
+import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos;
+import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos.RegionStoreSequenceIds;
 import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos;
-import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RegionStoreSequenceIds;
 import org.apache.hadoop.hbase.util.ByteStringer;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Threads;
@@ -74,6 +74,7 @@ import org.apache.zookeeper.proto.DeleteRequest;
 import org.apache.zookeeper.proto.SetDataRequest;
 import org.apache.zookeeper.server.ZooKeeperSaslServer;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.protobuf.InvalidProtocolBufferException;
 
 /**
@@ -93,6 +94,25 @@ public class ZKUtil {
   public static final char ZNODE_PATH_SEPARATOR = '/';
   private static int zkDumpConnectionTimeOut;
 
+  // The Quorum for the ZK cluster can have one the following format (see examples below):
+  // (1). s1,s2,s3 (no client port in the list, the client port could be obtained from clientPort)
+  // (2). s1:p1,s2:p2,s3:p3 (with client port, which could be same or different for each server,
+  //      in this case, the clientPort would be ignored)
+  // (3). s1:p1,s2,s3:p3 (mix of (1) and (2) - if port is not specified in a server, it would use
+  //      the clientPort; otherwise, it would use the specified port)
+  @VisibleForTesting
+  public static class ZKClusterKey {
+    public String quorumString;
+    public int clientPort;
+    public String znodeParent;
+
+    ZKClusterKey(String quorumString, int clientPort, String znodeParent) {
+      this.quorumString = quorumString;
+      this.clientPort = clientPort;
+      this.znodeParent = znodeParent;
+    }
+  }
+
   /**
    * Creates a new connection to ZooKeeper, pulling settings and ensemble config
    * from the specified configuration object using methods from {@link ZKConfig}.
@@ -106,8 +126,7 @@ public class ZKUtil {
    */
   public static RecoverableZooKeeper connect(Configuration conf, Watcher watcher)
   throws IOException {
-    Properties properties = ZKConfig.makeZKProps(conf);
+    String ensemble = ZKConfig.getZKQuorumServersString(conf);
-    String ensemble = ZKConfig.getZKQuorumServersString(properties);
     return connect(conf, ensemble, watcher);
   }
 
@@ -381,10 +400,10 @@ public class ZKUtil {
    */
   public static void applyClusterKeyToConf(Configuration conf, String key)
       throws IOException{
-    String[] parts = transformClusterKey(key);
+    ZKClusterKey zkClusterKey = transformClusterKey(key);
-    conf.set(HConstants.ZOOKEEPER_QUORUM, parts[0]);
+    conf.set(HConstants.ZOOKEEPER_QUORUM, zkClusterKey.quorumString);
-    conf.set(HConstants.ZOOKEEPER_CLIENT_PORT, parts[1]);
+    conf.setInt(HConstants.ZOOKEEPER_CLIENT_PORT, zkClusterKey.clientPort);
-    conf.set(HConstants.ZOOKEEPER_ZNODE_PARENT, parts[2]);
+    conf.set(HConstants.ZOOKEEPER_ZNODE_PARENT, zkClusterKey.znodeParent);
   }
 
   /**
@@ -395,14 +414,53 @@ public class ZKUtil {
    * @return the three configuration in the described order
    * @throws IOException
    */
-  public static String[] transformClusterKey(String key) throws IOException {
+  public static ZKClusterKey transformClusterKey(String key) throws IOException {
     String[] parts = key.split(":");
-    if (parts.length != 3) {
+
-      throw new IOException("Cluster key passed " + key + " is invalid, the format should be:" +
+    if (parts.length == 3) {
-          HConstants.ZOOKEEPER_QUORUM + ":hbase.zookeeper.client.port:"
+      return new ZKClusterKey(parts [0], Integer.parseInt(parts [1]), parts [2]);
-          + HConstants.ZOOKEEPER_ZNODE_PARENT);
     }
-    return parts;
+
+    if (parts.length > 3) {
+      // The quorum could contain client port in server:clientport format, try to transform more.
+      String zNodeParent = parts [parts.length - 1];
+      String clientPort = parts [parts.length - 2];
+
+      // The first part length is the total length minus the lengths of other parts and minus 2 ":"
+      int endQuorumIndex = key.length() - zNodeParent.length() - clientPort.length() - 2;
+      String quorumStringInput = key.substring(0, endQuorumIndex);
+      String[] serverHosts = quorumStringInput.split(",");
+
+      // The common case is that every server has its own client port specified - this means
+      // that (total parts - the ZNodeParent part - the ClientPort part) is equal to
+      // (the number of "," + 1) - "+ 1" because the last server has no ",".
+      if ((parts.length - 2) == (serverHosts.length + 1)) {
+        return new ZKClusterKey(quorumStringInput, Integer.parseInt(clientPort), zNodeParent);
+      }
+
+      // For the uncommon case that some servers has no port specified, we need to build the
+      // server:clientport list using default client port for servers without specified port.
+      return new ZKClusterKey(
+        ZKConfig.buildQuorumServerString(serverHosts, clientPort),
+        Integer.parseInt(clientPort),
+        zNodeParent);
+    }
+
+    throw new IOException("Cluster key passed " + key + " is invalid, the format should be:" +
+          HConstants.ZOOKEEPER_QUORUM + ":" + HConstants.ZOOKEEPER_CLIENT_PORT + ":"
+          + HConstants.ZOOKEEPER_ZNODE_PARENT);
+  }
+
+  /**
+   * Standardize the ZK quorum string: make it a "server:clientport" list, separated by ','
+   * @param quorumStringInput a string contains a list of servers for ZK quorum
+   * @param clientPort the default client port
+   * @return the string for a list of "server:port" separated by ","
+   */
+  @VisibleForTesting
+  public static String standardizeQuorumServerString(String quorumStringInput, String clientPort) {
+    String[] serverHosts = quorumStringInput.split(",");
+    return ZKConfig.buildQuorumServerString(serverHosts, clientPort);
   }
 
   //
@@ -939,7 +997,8 @@ public class ZKUtil {
     // Detection for embedded HBase client with jaas configuration
     // defined for third party programs.
     try {
-      javax.security.auth.login.Configuration testConfig = javax.security.auth.login.Configuration.getConfiguration();
+      javax.security.auth.login.Configuration testConfig =
+          javax.security.auth.login.Configuration.getConfiguration();
       if(testConfig.getAppConfigurationEntry("Client") == null) {
         return false;
       }
@@ -1207,7 +1266,6 @@ public class ZKUtil {
       } catch (InterruptedException ie) {
         zkw.interruptedException(ie);
       }
-
     } catch(InterruptedException ie) {
       zkw.interruptedException(ie);
     }
@@ -1334,8 +1392,8 @@ public class ZKUtil {
           deleteNodeRecursively(zkw, joinZNode(node, child));
         }
       }
-      //Zookeeper Watches are one time triggers; When children of parent nodes are deleted recursively. 
+      //Zookeeper Watches are one time triggers; When children of parent nodes are deleted
-      //Must set another watch, get notified of delete node   
+      //recursively, must set another watch, get notified of delete node
       if (zkw.getRecoverableZooKeeper().exists(node, zkw) != null){
         zkw.getRecoverableZooKeeper().delete(node, -1);
       }
@@ -1986,7 +2044,8 @@ public class ZKUtil {
    * @see #logZKTree(ZooKeeperWatcher, String)
    * @throws KeeperException if an unexpected exception occurs
    */
-  protected static void logZKTree(ZooKeeperWatcher zkw, String root, String prefix) throws KeeperException {
+  protected static void logZKTree(ZooKeeperWatcher zkw, String root, String prefix)
+      throws KeeperException {
     List<String> children = ZKUtil.listChildrenNoWatch(zkw, root);
     if (children == null) return;
     for (String child : children) {
@@ -2044,10 +2103,10 @@ public class ZKUtil {
    */
   public static byte[] regionSequenceIdsToByteArray(final Long regionLastFlushedSequenceId,
       final Map<byte[], Long> storeSequenceIds) {
-    ZooKeeperProtos.RegionStoreSequenceIds.Builder regionSequenceIdsBuilder =
+    ClusterStatusProtos.RegionStoreSequenceIds.Builder regionSequenceIdsBuilder =
-        ZooKeeperProtos.RegionStoreSequenceIds.newBuilder();
+        ClusterStatusProtos.RegionStoreSequenceIds.newBuilder();
-    ZooKeeperProtos.StoreSequenceId.Builder storeSequenceIdBuilder =
+    ClusterStatusProtos.StoreSequenceId.Builder storeSequenceIdBuilder =
-        ZooKeeperProtos.StoreSequenceId.newBuilder();
+        ClusterStatusProtos.StoreSequenceId.newBuilder();
     if (storeSequenceIds != null) {
       for (Map.Entry<byte[], Long> e : storeSequenceIds.entrySet()){
         byte[] columnFamilyName = e.getKey();
@@ -2074,7 +2133,7 @@ public class ZKUtil {
       throw new DeserializationException("Unable to parse RegionStoreSequenceIds.");
     }
     RegionStoreSequenceIds.Builder regionSequenceIdsBuilder =
-        ZooKeeperProtos.RegionStoreSequenceIds.newBuilder();
+        ClusterStatusProtos.RegionStoreSequenceIds.newBuilder();
     int pblen = ProtobufUtil.lengthOfPBMagic();
     RegionStoreSequenceIds storeIds = null;
     try {