HBASE-3071 Graceful decommissioning of a regionserver
git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1088879 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Michael Stack
parent
b9ee682e70
commit
06a21879a4
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@ -134,6 +134,7 @@ Release 0.91.0 - Unreleased
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HBASE-3559 Move report of split to master OFF the heartbeat channel
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HBASE-3573 Move shutdown messaging OFF hearbeat; prereq for fix of
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hbase-1502
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HBASE-3071 Graceful decommissioning of a regionserver
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NEW FEATURES
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@ -0,0 +1,83 @@
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#!/usr/bin/env bash
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#
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#/**
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# * Copyright 2011 The Apache Software Foundation
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# *
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# * Licensed to the Apache Software Foundation (ASF) under one
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# * or more contributor license agreements. See the NOTICE file
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# * distributed with this work for additional information
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# * regarding copyright ownership. The ASF licenses this file
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# * to you under the Apache License, Version 2.0 (the
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# * "License"); you may not use this file except in compliance
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# * with the License. You may obtain a copy of the License at
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# *
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# * http://www.apache.org/licenses/LICENSE-2.0
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# *
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# * Unless required by applicable law or agreed to in writing, software
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# * distributed under the License is distributed on an "AS IS" BASIS,
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# * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# * See the License for the specific language governing permissions and
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# * limitations under the License.
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# */
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# Move regions off a server then stop it. Optionally restart and reload.
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# Turn off the balancer before running this script.
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function usage {
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echo "Usage: graceful_stop.sh [--config <conf-dir>] [--restart] [--reload] <hostname>"
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echo " restart If we should restart after graceful stop"
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echo " reload Move offloaded regions back on to the stopped server"
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echo " debug Move offloaded regions back on to the stopped server"
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echo " hostname Hostname of server we are to stop"
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exit 1
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}
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if [ $# -lt 1 ]; then
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usage
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fi
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bin=`dirname "$0"`
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bin=`cd "$bin">/dev/null; pwd`
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# This will set HBASE_HOME, etc.
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. "$bin"/hbase-config.sh
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# Get arguments
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restart=
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reload=
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debug=
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while [ $# -gt 0 ]
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do
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case "$1" in
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--restart) restart=true; shift;;
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--reload) reload=true; shift;;
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--debug) debug="--debug"; shift;;
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--) shift; break;;
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-*) usage ;;
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*) break;; # terminate while loop
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esac
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done
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# "$@" contains the rest. Must be at least the hostname left.
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if [ $# -lt 1 ]; then
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usage
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fi
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hostname=$1
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filename="/tmp/$hostname"
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# Run the region mover script.
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echo "Unloading $hostname region(s)"
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HBASE_NOEXEC=true "$bin"/hbase org.jruby.Main "$bin"/region_mover.rb --file=$filename $debug unload $hostname
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echo "Unloaded $hostname region(s)"
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# Stop the server. Have to put hostname into its own little file for hbase-daemons.sh
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hosts="/tmp/$(basename $0).$$.tmp"
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echo $hostname >> $hosts
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"$bin"/hbase-daemons.sh --hosts ${hosts} stop regionserver
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if [ "$restart" != "" ]; then
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"$bin"/hbase-daemons.sh --hosts ${hosts} start regionserver
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if [ "$reload" != "" ]; then
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echo "Reloading $hostname region(s)"
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HBASE_NOEXEC=true "$bin"/hbase org.jruby.Main "$bin"/region_mover.rb --file=$filename $debug load $hostname
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echo "Reloaded $hostname region(s)"
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fi
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fi
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# Cleanup tmp files.
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trap "rm -f "/tmp/$(basename $0).*.tmp" &> /dev/null" EXIT
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@ -276,5 +276,9 @@ if [ "x$JAVA_LIBRARY_PATH" != "x" ]; then
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HBASE_OPTS="$HBASE_OPTS -Djava.library.path=$JAVA_LIBRARY_PATH"
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fi
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# run it
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# Exec unless HBASE_NOEXEC is set.
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if [ "${HBASE_NOEXEC}" != "" ]; then
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"$JAVA" $JAVA_HEAP_MAX $HBASE_OPTS -classpath "$CLASSPATH" $CLASS "$@"
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else
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exec "$JAVA" $JAVA_HEAP_MAX $HBASE_OPTS -classpath "$CLASSPATH" $CLASS "$@"
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fi
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@ -38,7 +38,7 @@ bin=`cd "$bin">/dev/null; pwd`
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. $bin/hbase-config.sh
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remote_cmd="cd ${HBASE_HOME}; $bin/hbase-daemon.sh --config ${HBASE_CONF_DIR} $@"
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args="--config ${HBASE_CONF_DIR} $remote_cmd"
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args="--hosts ${HBASE_REGIONSERVERS} --config ${HBASE_CONF_DIR} $remote_cmd"
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command=$2
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case $command in
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@ -0,0 +1,434 @@
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# Copyright 2011 The Apache Software Foundation
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#
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# Licensed to the Apache Software Foundation (ASF) under one
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# or more contributor license agreements. See the NOTICE file
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# distributed with this work for additional information
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# regarding copyright ownership. The ASF licenses this file
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# to you under the Apache License, Version 2.0 (the
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# "License"); you may not use this file except in compliance
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# with the License. You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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# Moves regions. Will confirm region access in current location and will
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# not move a new region until successful confirm of region loading in new
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# location. Presumes balancer is disabled when we run (not harmful if its
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# on but this script and balancer will end up fighting each other).
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# Does not work for case of multiple regionservers all running on the
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# one node.
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require 'optparse'
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include Java
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import org.apache.hadoop.hbase.HConstants
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import org.apache.hadoop.hbase.HBaseConfiguration
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import org.apache.hadoop.hbase.client.HBaseAdmin
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import org.apache.hadoop.hbase.client.Get
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import org.apache.hadoop.hbase.client.Scan
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import org.apache.hadoop.hbase.client.HTable
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import org.apache.hadoop.hbase.client.HConnectionManager
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import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter;
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import org.apache.hadoop.hbase.HServerAddress
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import org.apache.hadoop.hbase.util.Bytes
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import org.apache.hadoop.hbase.util.Writables
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import org.apache.hadoop.conf.Configuration
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import org.apache.commons.logging.Log
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import org.apache.commons.logging.LogFactory
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# Name of this script
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NAME = "region_mover"
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# Get root table reference
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def getRootTable(config)
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# Keep meta reference in ruby global
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if not $ROOT
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$ROOT = HTable.new(config, HConstants::ROOT_TABLE_NAME)
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end
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return $ROOT
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end
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# Get meta table reference
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def getMetaTable(config)
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# Keep meta reference in ruby global
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if not $META
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$META = HTable.new(config, HConstants::META_TABLE_NAME)
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end
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return $META
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end
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# Get table instance.
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# Maintains cache of table instances.
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def getTable(config, name)
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# Keep dictionary of tables in ruby global
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if not $TABLES
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$TABLES = {}
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end
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key = Bytes.toString(name)
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if not $TABLES[key]
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$TABLES[key] = HTable.new(config, name)
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end
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return $TABLES[key]
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end
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# Returns true if passed region is still on 'original' when we look at .META.
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def isSameServer(admin, r, original)
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server = getServerNameForRegion(admin, r)
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return false unless server
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return true unless original
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return server == original
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end
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class RubyAbortable
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include org.apache.hadoop.hbase.Abortable
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def abort(why, e)
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puts "ABORTED! why=" + why + ", e=" + e.to_s
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end
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end
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# Get servername that is up in .META.; this is hostname + port + startcode comma-delimited.
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# Can return nil
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def getServerNameForRegion(admin, r)
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if r.isRootRegion()
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# Hack
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tracker = org.apache.hadoop.hbase.zookeeper.RootRegionTracker.new(admin.getConnection().getZooKeeperWatcher(), RubyAbortable.new())
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tracker.start()
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while not tracker.isLocationAvailable()
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sleep 0.1
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end
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# Make a fake servername by appending ','
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rootServer = tracker.getRootRegionLocation().toString() + ","
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tracker.stop()
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return rootServer
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end
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table = nil
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if r.isMetaRegion()
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table = getRootTable(admin.getConfiguration())
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else
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table = getMetaTable(admin.getConfiguration())
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end
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g = Get.new(r.getRegionName())
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g.addColumn(HConstants::CATALOG_FAMILY, HConstants::SERVER_QUALIFIER)
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g.addColumn(HConstants::CATALOG_FAMILY, HConstants::STARTCODE_QUALIFIER)
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result = table.get(g)
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server = result.getValue(HConstants::CATALOG_FAMILY, HConstants::SERVER_QUALIFIER)
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startcode = result.getValue(HConstants::CATALOG_FAMILY, HConstants::STARTCODE_QUALIFIER)
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return nil unless server
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return java.lang.String.new(Bytes.toString(server)).replaceFirst(":", ",") + "," + Bytes.toLong(startcode).to_s
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end
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# Trys to scan a row from passed region
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# Throws exception if can't
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def isSuccessfulScan(admin, r)
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scan = Scan.new(r.getStartKey())
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scan.setBatch(1)
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scan.setCaching(1)
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scan.setFilter(FirstKeyOnlyFilter.new())
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table = getTable(admin.getConfiguration(), r.getTableDesc().getName())
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scanner = table.getScanner(scan)
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begin
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results = scanner.next()
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# We might scan into next region, this might be an empty table.
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# But if no exception, presume scanning is working.
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ensure
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scanner.close()
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table.close()
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end
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end
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# Check region has moved successful and is indeed hosted on another server
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# Wait until that is the case.
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def move(admin, r, newServer, original)
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# Now move it. Do it in a loop so can retry if fail. Have seen issue where
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# we tried move region but failed and retry put it back on old location;
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# retry in this case.
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retries = admin.getConfiguration.getInt("hbase.move.retries.max", 5)
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count = 0
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same = true
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while count < retries and same
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if count > 0
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$LOG.info("Retry " + count.to_s + " of maximum " + retries.to_s)
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end
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count = count + 1
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begin
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admin.move(Bytes.toBytes(r.getEncodedName()), Bytes.toBytes(newServer))
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rescue java.lang.reflect.UndeclaredThrowableException => e
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$LOG.info("Exception moving " + r.getEncodedName() +
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"; split/moved? Continuing: " + e)
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return
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end
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# Wait till its up on new server before moving on
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maxWaitInSeconds = admin.getConfiguration.getInt("hbase.move.wait.max", 60)
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maxWait = Time.now + maxWaitInSeconds
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while Time.now < maxWait
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same = isSameServer(admin, r, original)
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break unless same
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sleep 0.1
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end
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end
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raise RuntimeError, "Region stuck on #{original}, newserver=#{newServer}" if same
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# Assert can Scan from new location.
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isSuccessfulScan(admin, r)
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end
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# Return the hostname portion of a servername (all up to first ',')
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def getHostnamePortFromServerName(serverName)
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parts = serverName.split(',')
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return parts[0] + ":" + parts[1]
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end
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# Return the hostname:port out of a servername (all up to first ',')
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def getHostnameFromServerName(serverName)
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return serverName.split(',')[0]
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end
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# Return array of servernames where servername is hostname+port+startcode
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# comma-delimited
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def getServers(admin)
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serverInfos = admin.getClusterStatus().getServerInfo()
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servers = []
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for server in serverInfos
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servers << server.getServerName()
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end
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return servers
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end
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# Remove the servername whose hostname portion matches from the passed
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# array of servers. Returns as side-effect the servername removed.
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def stripServer(servers, hostname)
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count = servers.length
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servername = nil
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for server in servers
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if getHostnameFromServerName(server) == hostname
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servername = servers.delete(server)
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end
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end
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# Check server to exclude is actually present
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raise RuntimeError, "Server %s not online" % hostname unless servers.length < count
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return servername
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end
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# Return servername that matches passed hostname
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def getServerName(servers, hostname)
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servername = nil
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for server in servers
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if getHostnameFromServerName(server) == hostname
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servername = server
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break
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end
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end
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raise ArgumentError, "Server %s not online" % hostname unless servername
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return servername
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end
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# Create a logger and disable the DEBUG-level annoying client logging
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def configureLogging(options)
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apacheLogger = LogFactory.getLog(NAME)
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# Configure log4j to not spew so much
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unless (options[:debug])
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logger = org.apache.log4j.Logger.getLogger("org.apache.hadoop.hbase.client")
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logger.setLevel(org.apache.log4j.Level::INFO)
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end
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return apacheLogger
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end
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# Get configuration instance
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def getConfiguration()
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config = HBaseConfiguration.create()
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# No prefetching on .META.
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config.setInt("hbase.client.prefetch.limit", 1)
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# Make a config that retries at short intervals many times
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config.setInt("hbase.client.pause", 500)
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config.setInt("hbase.client.retries.number", 100)
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return config
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end
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# Now get list of regions on targetServer
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def getRegions(config, servername)
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connection = HConnectionManager::getConnection(config)
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hsa = HServerAddress.new(getHostnamePortFromServerName(servername))
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rs = connection.getHRegionConnection(hsa)
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return rs.getOnlineRegions()
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end
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def deleteFile(filename)
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f = java.io.File.new(filename)
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f.delete() if f.exists()
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end
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# Write HRegionInfo to file
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# Need to serialize in case non-printable characters.
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# Format is count of regionnames followed by serialized regionnames.
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def writeFile(filename, regions)
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fos = java.io.FileOutputStream.new(filename)
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dos = java.io.DataOutputStream.new(fos)
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# Write out a count of region names
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dos.writeInt(regions.size())
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# Write actual region names.
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for r in regions
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bytes = Writables.getBytes(r)
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Bytes.writeByteArray(dos, bytes)
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end
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dos.close()
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end
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# See writeFile above.
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# Returns array of HRegionInfos
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def readFile(filename)
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f = java.io.File.new(filename)
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return java.util.ArrayList.new() unless f.exists()
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fis = java.io.FileInputStream.new(f)
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dis = java.io.DataInputStream.new(fis)
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# Read count of regions
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count = dis.readInt()
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regions = java.util.ArrayList.new(count)
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index = 0
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while index < count
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regions.add(Writables.getHRegionInfo(Bytes.readByteArray(dis)))
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index = index + 1
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end
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dis.close()
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return regions
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end
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# Move regions off the passed hostname
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def unloadRegions(options, hostname)
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# Get configuration
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config = getConfiguration()
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# Clean up any old files.
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filename = getFilename(options, hostname)
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deleteFile(filename)
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# Get an admin instance
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admin = HBaseAdmin.new(config)
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servers = getServers(admin)
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# Remove the server we are unloading from from list of servers.
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# Side-effect is the servername that matches this hostname
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servername = stripServer(servers, hostname)
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movedRegions = java.util.ArrayList.new()
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while true
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rs = getRegions(config, servername)
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break if rs.length == 0
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count = 0
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$LOG.info("Moving " + rs.length.to_s + " region(s) from " + servername +
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" during this cycle");
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for r in rs
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# Get a random server to move the region to.
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server = servers[rand(servers.length)]
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$LOG.info("Moving region " + r.getEncodedName() + " (" + count.to_s +
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" of " + rs.length.to_s + ") to server=" + server);
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count = count + 1
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# Assert we can scan region in its current location
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isSuccessfulScan(admin, r)
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# Now move it.
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move(admin, r, server, servername)
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movedRegions.add(r)
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end
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end
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if movedRegions.size() > 0
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# Write out file of regions moved
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writeFile(filename, movedRegions)
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$LOG.info("Wrote list of moved regions to " + filename)
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end
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end
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# Move regions to the passed hostname
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def loadRegions(options, hostname)
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# Get configuration
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config = getConfiguration()
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# Get an admin instance
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admin = HBaseAdmin.new(config)
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filename = getFilename(options, hostname)
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regions = readFile(filename)
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return if regions.isEmpty()
|
||||
servername = nil
|
||||
# Wait till server is up
|
||||
maxWaitInSeconds = admin.getConfiguration.getInt("hbase.serverstart.wait.max", 180)
|
||||
maxWait = Time.now + maxWaitInSeconds
|
||||
while Time.now < maxWait
|
||||
servers = getServers(admin)
|
||||
begin
|
||||
servername = getServerName(servers, hostname)
|
||||
rescue ArgumentError => e
|
||||
$LOG.info("hostname=" + hostname.to_s + " is not up yet, waiting");
|
||||
end
|
||||
break if servername
|
||||
sleep 0.5
|
||||
end
|
||||
$LOG.info("Moving " + regions.size().to_s + " regions to " + servername)
|
||||
count = 0
|
||||
for r in regions
|
||||
exists = false
|
||||
begin
|
||||
exists = isSuccessfulScan(admin, r)
|
||||
rescue org.apache.hadoop.hbase.NotServingRegionException => e
|
||||
$LOG.info("Failed scan of " + e.message)
|
||||
end
|
||||
count = count + 1
|
||||
next unless exists
|
||||
currentServer = getServerNameForRegion(admin, r)
|
||||
if currentServer and currentServer == servername
|
||||
$LOG.info("Region " + r.getRegionNameAsString() + " (" + count.to_s +
|
||||
" of " + regions.length.to_s + ") already on target server=" + servername)
|
||||
next
|
||||
end
|
||||
$LOG.info("Moving region " + r.getEncodedName() + " (" + count.to_s +
|
||||
" of " + regions.length.to_s + ") to server=" + servername);
|
||||
move(admin, r, servername, currentServer)
|
||||
end
|
||||
end
|
||||
|
||||
def getFilename(options, targetServer)
|
||||
filename = options[:file]
|
||||
if not filename
|
||||
filename = "/tmp/" + targetServer
|
||||
end
|
||||
return filename
|
||||
end
|
||||
|
||||
|
||||
# Do command-line parsing
|
||||
options = {}
|
||||
optparse = OptionParser.new do |opts|
|
||||
opts.banner = "Usage: #{NAME}.rb [options] load|unload <hostname>"
|
||||
opts.separator 'Load or unload regions by moving one at a time'
|
||||
options[:file] = nil
|
||||
opts.on('-f', '--filename=FILE', 'File to save regions list into unloading, or read from loading; default /tmp/<hostname>') do |file|
|
||||
options[:file] = file
|
||||
end
|
||||
opts.on('-h', '--help', 'Display usage information') do
|
||||
puts opts
|
||||
exit
|
||||
end
|
||||
options[:debug] = false
|
||||
opts.on('-d', '--debug', 'Display extra debug logging') do
|
||||
options[:debug] = true
|
||||
end
|
||||
end
|
||||
optparse.parse!
|
||||
|
||||
# Check ARGVs
|
||||
if ARGV.length < 2
|
||||
puts optparse
|
||||
exit 1
|
||||
end
|
||||
hostname = ARGV[1]
|
||||
if not hostname
|
||||
opts optparse
|
||||
exit 2
|
||||
end
|
||||
# Create a logger and save it to ruby global
|
||||
$LOG = configureLogging(options)
|
||||
case ARGV[0]
|
||||
when 'load'
|
||||
loadRegions(options, hostname)
|
||||
when 'unload'
|
||||
unloadRegions(options, hostname)
|
||||
else
|
||||
puts optparse
|
||||
exit 3
|
||||
end
|
||||
|
|
@ -1076,6 +1076,56 @@ public static byte[][] getHexSplits(String startKey, String endKey, int numRegio
|
|||
<section xml:id="compression.tool"><title>Compression Tool</title>
|
||||
<para>See <link linkend="compression.tool" >Compression Tool</link>.</para>
|
||||
</section>
|
||||
<section xml:id="decommission"><title>Node Decommission</title>
|
||||
<para>You can have a node gradually shed its load and then shutdown using the
|
||||
<command>graceful_restart.sh</command> script. Here is its usage:
|
||||
<computeroutput>$ ./bin/graceful_stop.sh
|
||||
Usage: graceful_stop.sh [--config &conf-dir>] [--restart] [--reload] &hostname>
|
||||
restart If we should restart after graceful stop
|
||||
reload Move offloaded regions back on to the stopped server
|
||||
debug Move offloaded regions back on to the stopped server
|
||||
hostname Hostname of server we are to stop</computeroutput>
|
||||
</para>
|
||||
<para>
|
||||
To decommission a loaded regionserver, run the following:
|
||||
<programlisting>$ ./bin/graceful_stop.sh HOSTNAME</programlisting>
|
||||
where <varname>HOSTNAME</varname> is the host carrying the RegionServer
|
||||
you would decommission. The script will move the regions off the
|
||||
decommissioned regionserver one at a time to minimize region churn.
|
||||
It will verify the region deployed in the new location before it
|
||||
will moves the next region and so on until the decommissioned server
|
||||
is carrying zero regions. At this point, the <command>graceful_stop</command>
|
||||
tells the RegionServer stop. The master will at this point notice the
|
||||
RegionServer gone but all regions will have already been redeployed
|
||||
and because the RegionServer went down cleanly, there will be no
|
||||
WAL logs to split.
|
||||
<note><title>Load Balancer</title>
|
||||
<para>
|
||||
It is assumed that the Region Load Balancer is disabled while the
|
||||
<command>graceful_stop</command> script runs (otherwise the balancer
|
||||
and the decommission script will end up fighting over region deployments).
|
||||
Use the shell to disable the balancer:
|
||||
<programlisting>hbase(main):001:0> balance_switch false
|
||||
true
|
||||
0 row(s) in 0.3590 seconds</programlisting>
|
||||
This turns the balancer OFF. To reenable, do:
|
||||
<programlisting>hbase(main):001:0> balance_switch true
|
||||
false
|
||||
0 row(s) in 0.3590 seconds</programlisting>
|
||||
</para>
|
||||
</note>
|
||||
</para>
|
||||
<para>
|
||||
You can also ask this script to restart a RegionServer after the shutdown
|
||||
AND move its old regions back into place. The latter you might do to
|
||||
retain data locality. A primitive rolling restart might be effected by
|
||||
running something like the following:
|
||||
<programlisting>$ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --reload --debug $i; done &> /tmp/log.txt &
|
||||
</programlisting>
|
||||
Tail the output of <filename>/tmp/log.txt</filename> to follow the scripts
|
||||
progress.
|
||||
</para>
|
||||
</section>
|
||||
</appendix>
|
||||
|
||||
<appendix xml:id="compression">
|
||||
|
|
|
|||
Loading…
Reference in New Issue