HADOOP-1445 Support updates across region splits and compactions

git-svn-id: https://svn.apache.org/repos/asf/lucene/hadoop/trunk/src/contrib/hbase@544188 13f79535-47bb-0310-9956-ffa450edef68
2007-06-04 17:14:10 +00:00 · 2007-06-04 17:14:10 +00:00 · ac718209e5
parent 7c3d11974b
commit ac718209e5
24 changed files with 1437 additions and 984 deletions
--- a/CHANGES.txt
+++ b/CHANGES.txt
@ -22,3 +22,4 @@ Trunk (unreleased changes)
     add/remove column.
 12. HADOOP-1392. Part2: includes table compaction by merging adjacent regions
     that have shrunk in size.
 13. HADOOP-1445 Support updates across region splits and compactions
--- a/conf/hbase-default.xml
+++ b/conf/hbase-default.xml
@ -21,21 +21,18 @@
    </description>
  </property>
  <property>
-    <name>hbase.client.timeout.length</name>
+    <name>hbase.client.pause</name>
-    <value>10000</value>
+    <value>30000</value>
-    <description>Client timeout in milliseconds</description>
+    <description>General client pause value.  Used mostly as value to wait
-  </property>
+    before running a retry of a failed get, region lookup, etc.</description>
  <property>
    <name>hbase.client.timeout.number</name>
    <value>5</value>
    <description>Try this many timeouts before giving up.
    </description>
  </property>
  <property>
    <name>hbase.client.retries.number</name>
-    <value>2</value>
+    <value>5</value>
-    <description>Count of maximum retries fetching the root region from root
+    <description>Maximum retries.  Used as maximum for all retryable
-        region server.
+    operations such as fetching of the root region from root region
    server, getting a cell's value, starting a row update, etc.
    Default: 5.
    </description>
  </property>
  <property>
@ -51,6 +48,12 @@
    <description>HMaster server lease period in milliseconds. Default is
    30 seconds.</description>
  </property>
  <property>
    <name>hbase.regionserver.lease.period</name>
    <value>180000</value>
    <description>HRegion server lease period in milliseconds. Default is
    180 seconds.</description>
  </property>
  <property>
    <name>hbase.server.thread.wakefrequency</name>
    <value>10000</value>
@ -58,12 +61,6 @@
    Used as sleep interval by service threads such as META scanner and log roller.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.lease.period</name>
    <value>30000</value>
    <description>HRegion server lease period in milliseconds. Default is
    30 seconds.</description>
  </property>
  <property>
    <name>hbase.regionserver.handler.count</name>
    <value>10</value>
@ -80,5 +77,27 @@
    tests to be responsive.
    </description>
  </property>
-
+  <property>
    <name>hbase.regionserver.maxlogentries</name>
    <value>30000</value>
    <description>Rotate the logs when count of entries exceeds this value.
    Default: 30,000
    </description>
  </property>
  <property>
    <name>hbase.hregion.maxunflushed</name>
    <value>10000</value>
    <description>
    Memcache will be flushed to disk if number of Memcache writes
    are in excess of this number.
    </description>
  </property>
  <property>
    <name>hbase.hregion.max.filesize</name>
    <value>134217728</value>
    <description>
    Maximum desired file size for an HRegion.  If filesize exceeds
    value + (value / 2), the HRegion is split in two.  Default: 128M.
    </description>
  </property>
 </configuration>
--- a/conf/hbase-site.xml
+++ b/conf/hbase-site.xml
@ -1,4 +1,54 @@
 <?xml version="1.0"?>
 <?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
 <configuration>
  <property>
    <name>hbase.regiondir</name>
    <value>hbase</value>
    <description>The directory shared by region servers.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.msginterval</name>
    <value>1000</value>
    <description>Interval between messages from the RegionServer to HMaster
    in milliseconds.  Default is 15. Set this value low if you want unit
    tests to be responsive.
    </description>
  </property>
  <!--
  <property>
    <name>hbase.master.meta.thread.rescanfrequency</name>
    <value>600000</value>
    <description>How long the HMaster sleeps (in milliseconds) between scans of
    the root and meta tables.
    </description>
  </property>
  <property>
    <name>hbase.master.lease.period</name>
    <value>360000</value>
    <description>HMaster server lease period in milliseconds. Default is
    180 seconds.</description>
  </property>
  <property>
    <name>hbase.regionserver.lease.period</name>
    <value>360000</value>
    <description>HMaster server lease period in milliseconds. Default is
    180 seconds.</description>
  </property>
  -->
  <!--
  <property>
    <name>hbase.hregion.max.filesize</name>
    <value>3421223</value>
    <description>
    Maximum desired file size for an HRegion.  If filesize exceeds
    value + (value / 2), the HRegion is split in two.  Default: 128M.
    </description>
  </property>
  <property>
    <name>hbase.client.timeout.length</name>
    <value>10000</value>
    <description>Client timeout in milliseconds</description>
  </property>
  -->
 </configuration>
--- a/src/java/org/apache/hadoop/hbase/HAbstractScanner.java
+++ b/src/java/org/apache/hadoop/hbase/HAbstractScanner.java
@ -21,6 +21,8 @@ import java.util.Vector;
 import java.util.regex.Pattern;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.io.DataInputBuffer;
 import org.apache.hadoop.io.DataOutputBuffer;
 import org.apache.hadoop.io.BytesWritable;
@ -31,10 +33,11 @@ import org.apache.hadoop.io.Text;
 * Used by the concrete HMemcacheScanner and HStoreScanners
 ******************************************************************************/
 public abstract class HAbstractScanner implements HInternalScannerInterface {
  final Log LOG = LogFactory.getLog(this.getClass().getName());
  // Pattern to determine if a column key is a regex
-  private static Pattern isRegexPattern = Pattern.compile("^.*[\\\\+|^&*$\\[\\]\\}{)(]+.*$");
+  static Pattern isRegexPattern = Pattern.compile("^.*[\\\\+|^&*$\\[\\]\\}{)(]+.*$");
  // The kind of match we are doing on a column:
@ -42,7 +45,7 @@ public abstract class HAbstractScanner implements HInternalScannerInterface {
    FAMILY_ONLY,                        // Just check the column family name
    REGEX,                              // Column family + matches regex
    SIMPLE                              // Literal matching
-  };
+  }
  // This class provides column matching functions that are more sophisticated
  // than a simple string compare. There are three types of matching:
@ -89,15 +92,15 @@ public abstract class HAbstractScanner implements HInternalScannerInterface {
    // Matching method
-    boolean matches(Text col) throws IOException {
+    boolean matches(Text c) throws IOException {
      if(this.matchType == MATCH_TYPE.SIMPLE) {
-        return col.equals(this.col);
+        return c.equals(this.col);
      } else if(this.matchType == MATCH_TYPE.FAMILY_ONLY) {
-        return col.toString().startsWith(this.family);
+        return c.toString().startsWith(this.family);
      } else if(this.matchType == MATCH_TYPE.REGEX) {
-        return this.columnMatcher.matcher(col.toString()).matches();
+        return this.columnMatcher.matcher(c.toString()).matches();
      } else {
        throw new IOException("Invalid match type: " + this.matchType);
@ -201,20 +204,19 @@ public abstract class HAbstractScanner implements HInternalScannerInterface {
  public boolean isMultipleMatchScanner() {
    return this.multipleMatchers;
  }
  /**
   * Get the next set of values for this scanner.
   * 
-   * @param key - The key that matched
+   * @param key The key that matched
-   * @param results - all the results for that key.
+   * @param results All the results for <code>key</code>
-   * @return - true if a match was found
+   * @return true if a match was found
   * 
   * @see org.apache.hadoop.hbase.HScannerInterface#next(org.apache.hadoop.hbase.HStoreKey, java.util.TreeMap)
   */
  public boolean next(HStoreKey key, TreeMap<Text, BytesWritable> results)
  throws IOException {
    // Find the next row label (and timestamp)
    Text chosenRow = null;
    long chosenTimestamp = -1;
    for(int i = 0; i < keys.length; i++) {
@ -232,7 +234,6 @@ public abstract class HAbstractScanner implements HInternalScannerInterface {
    }
    // Grab all the values that match this row/timestamp
    boolean insertedItem = false;
    if(chosenRow != null) {
      key.setRow(chosenRow);
@ -241,7 +242,6 @@ public abstract class HAbstractScanner implements HInternalScannerInterface {
      for(int i = 0; i < keys.length; i++) {
        // Fetch the data
        while((keys[i] != null)
            && (keys[i].getRow().compareTo(chosenRow) == 0)) {
@ -256,9 +256,7 @@ public abstract class HAbstractScanner implements HInternalScannerInterface {
          }
          if(columnMatch(i)) {              
            // We only want the first result for any specific family member
            if(!results.containsKey(keys[i].getColumn())) {
              results.put(new Text(keys[i].getColumn()), vals[i]);
              insertedItem = true;
@ -277,7 +275,6 @@ public abstract class HAbstractScanner implements HInternalScannerInterface {
            && ((keys[i].getRow().compareTo(chosenRow) <= 0)
                || (keys[i].getTimestamp() > this.timestamp)
                || (! columnMatch(i)))) {
          getNext(i);
        }
      }
--- a/src/java/org/apache/hadoop/hbase/HClient.java
+++ b/src/java/org/apache/hadoop/hbase/HClient.java
@ -18,11 +18,14 @@ package org.apache.hadoop.hbase;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Random;
 import java.util.SortedMap;
 import java.util.TreeMap;
 import java.util.TreeSet;
 import java.util.concurrent.TimeUnit;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@ -30,6 +33,9 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.io.BytesWritable;
 import org.apache.hadoop.io.DataInputBuffer;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.io.retry.RetryPolicy;
 import org.apache.hadoop.io.retry.RetryPolicies;
 import org.apache.hadoop.io.retry.RetryProxy;
 import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.ipc.RemoteException;
@ -37,7 +43,7 @@ import org.apache.hadoop.ipc.RemoteException;
 * HClient manages a connection to a single HRegionServer.
 */
 public class HClient implements HConstants {
-  private final Log LOG = LogFactory.getLog(this.getClass().getName());
+  final Log LOG = LogFactory.getLog(this.getClass().getName());
  private static final Text[] META_COLUMNS = {
    COLUMN_FAMILY
@ -49,51 +55,55 @@ public class HClient implements HConstants {
  private static final Text EMPTY_START_ROW = new Text();
-  private long clientTimeout;
+  long pause;
-  private int numTimeouts;
+  int numRetries;
  private int numRetries;
  private HMasterInterface master;
  private final Configuration conf;
-  private static class TableInfo {
+  /*
   * Data structure that holds current location for a region and its info.
   */
  static class RegionLocation {
    public HRegionInfo regionInfo;
    public HServerAddress serverAddress;
-    TableInfo(HRegionInfo regionInfo, HServerAddress serverAddress) {
+    RegionLocation(HRegionInfo regionInfo, HServerAddress serverAddress) {
      this.regionInfo = regionInfo;
      this.serverAddress = serverAddress;
    }
    @Override
    public String toString() {
      return "address: " + this.serverAddress.toString() + ", regioninfo: " +
        this.regionInfo;
    }
  }
  // Map tableName -> (Map startRow -> (HRegionInfo, HServerAddress)
-  
+  private TreeMap<Text, SortedMap<Text, RegionLocation>> tablesToServers;
  private TreeMap<Text, SortedMap<Text, TableInfo>> tablesToServers;
  // For the "current" table: Map startRow -> (HRegionInfo, HServerAddress)
-  
+  private SortedMap<Text, RegionLocation> tableServers;
  private SortedMap<Text, TableInfo> tableServers;
  // Known region HServerAddress.toString() -> HRegionInterface 
  private TreeMap<String, HRegionInterface> servers;
  // For row mutation operations
-  private Text currentRegion;
+  Text currentRegion;
-  private HRegionInterface currentServer;
+  HRegionInterface currentServer;
-  private Random rand;
+  Random rand;
-  private long clientid;
+  long clientid;
  /** Creates a new HClient */
  public HClient(Configuration conf) {
    this.conf = conf;
-    this.clientTimeout = conf.getLong("hbase.client.timeout.length", 30 * 1000);
+    this.pause = conf.getLong("hbase.client.pause", 30 * 1000);
-    this.numTimeouts = conf.getInt("hbase.client.timeout.number", 5);
+    this.numRetries = conf.getInt("hbase.client.retries.number", 5);
    this.numRetries =  conf.getInt("hbase.client.retries.number", 2);
    this.master = null;
-    this.tablesToServers = new TreeMap<Text, SortedMap<Text, TableInfo>>();
+    this.tablesToServers = new TreeMap<Text, SortedMap<Text, RegionLocation>>();
    this.tableServers = null;
    this.servers = new TreeMap<String, HRegionInterface>();
@ -129,11 +139,13 @@ public class HClient implements HConstants {
    }
  }
-  /* Find the address of the master and connect to it */
+  /* Find the address of the master and connect to it
   */
  private void checkMaster() throws MasterNotRunningException {
    if (this.master != null) {
      return;
    }
    for(int tries = 0; this.master == null && tries < numRetries; tries++) {
      HServerAddress masterLocation =
        new HServerAddress(this.conf.get(MASTER_ADDRESS,
@ -144,7 +156,6 @@ public class HClient implements HConstants {
          (HMasterInterface)RPC.getProxy(HMasterInterface.class, 
            HMasterInterface.versionID, masterLocation.getInetSocketAddress(),
            this.conf);
        if(tryMaster.isMasterRunning()) {
          this.master = tryMaster;
          break;
@ -154,16 +165,18 @@ public class HClient implements HConstants {
          // This was our last chance - don't bother sleeping
          break;
        }
        LOG.info("Attempt " + tries + " of " + this.numRetries +
          " failed with <" + e + ">. Retrying after sleep of " + this.pause);
      }
-      // We either cannot connect to the master or it is not running.
+      // We either cannot connect to master or it is not running. Sleep & retry
      // Sleep and retry
      try {
-        Thread.sleep(this.clientTimeout);
+        Thread.sleep(this.pause);
      } catch(InterruptedException e) {
        // continue
      }
    }
    if(this.master == null) {
      throw new MasterNotRunningException();
    }
@ -210,7 +223,7 @@ public class HClient implements HConstants {
    // Save the current table
-    SortedMap<Text, TableInfo> oldServers = this.tableServers;
+    SortedMap<Text, RegionLocation> oldServers = this.tableServers;
    try {
      // Wait for new table to come on-line
@ -229,23 +242,21 @@ public class HClient implements HConstants {
  public synchronized void deleteTable(Text tableName) throws IOException {
    checkReservedTableName(tableName);
    checkMaster();
-    TableInfo firstMetaServer = getFirstMetaServerForTable(tableName);
+    RegionLocation firstMetaServer = getFirstMetaServerForTable(tableName);
    try {
      this.master.deleteTable(tableName);
    } catch(RemoteException e) {
      handleRemoteException(e);
    }
    // Wait until first region is deleted
-    
+    HRegionInterface server =
-    HRegionInterface server = getHRegionConnection(firstMetaServer.serverAddress);
+      getHRegionConnection(firstMetaServer.serverAddress);
    DataInputBuffer inbuf = new DataInputBuffer();
    HStoreKey key = new HStoreKey();
    HRegionInfo info = new HRegionInfo();
-    for(int tries = 0; tries < numRetries; tries++) {
+    for (int tries = 0; tries < numRetries; tries++) {
      long scannerId = -1L;
      try {
        scannerId = server.openScanner(firstMetaServer.regionInfo.regionName,
@ -258,7 +269,8 @@ public class HClient implements HConstants {
        for(int j = 0; j < values.length; j++) {
          if(values[j].getLabel().equals(COL_REGIONINFO)) {
            byte[] bytes = new byte[values[j].getData().getSize()];
-            System.arraycopy(values[j].getData().get(), 0, bytes, 0, bytes.length);
+            System.arraycopy(values[j].getData().get(), 0, bytes, 0,
              bytes.length);
            inbuf.reset(bytes, bytes.length);
            info.readFields(inbuf);
            if(info.tableDesc.getName().equals(tableName)) {
@ -274,27 +286,19 @@ public class HClient implements HConstants {
        if(scannerId != -1L) {
          try {
            server.close(scannerId);
          } catch(Exception e) {
            LOG.warn(e);
          }
        }
      }
      if(LOG.isDebugEnabled()) {
        LOG.debug("Sleep. Waiting for first region to be deleted from " + tableName);
      }
      try {
        Thread.sleep(clientTimeout);
      try {
        Thread.sleep(pause);
      } catch(InterruptedException e) {
-      }
+        // continue
      if(LOG.isDebugEnabled()) {
        LOG.debug("Wake. Waiting for first region to be deleted from " + tableName);
      }
    }
-    if(LOG.isDebugEnabled()) {
+    LOG.info("table " + tableName + " deleted");
      LOG.debug("table deleted " + tableName);
    }
  }
  public synchronized void addColumn(Text tableName, HColumnDescriptor column) throws IOException {
@ -322,7 +326,7 @@ public class HClient implements HConstants {
  public synchronized void enableTable(Text tableName) throws IOException {
    checkReservedTableName(tableName);
    checkMaster();
-    TableInfo firstMetaServer = getFirstMetaServerForTable(tableName);
+    RegionLocation firstMetaServer = getFirstMetaServerForTable(tableName);
    try {
      this.master.enableTable(tableName);
@ -379,20 +383,22 @@ public class HClient implements HConstants {
        LOG.debug("Sleep. Waiting for first region to be enabled from " + tableName);
      }
      try {
-        Thread.sleep(clientTimeout);
+        Thread.sleep(pause);
      } catch(InterruptedException e) {
        // continue
      }
      if(LOG.isDebugEnabled()) {
        LOG.debug("Wake. Waiting for first region to be enabled from " + tableName);
      }
    }
    LOG.info("Enabled table " + tableName);
  }
  public synchronized void disableTable(Text tableName) throws IOException {
    checkReservedTableName(tableName);
    checkMaster();
-    TableInfo firstMetaServer = getFirstMetaServerForTable(tableName);
+    RegionLocation firstMetaServer = getFirstMetaServerForTable(tableName);
    try {
      this.master.disableTable(tableName);
@ -449,14 +455,15 @@ public class HClient implements HConstants {
        LOG.debug("Sleep. Waiting for first region to be disabled from " + tableName);
      }
      try {
-        Thread.sleep(clientTimeout);
+        Thread.sleep(pause);
      } catch(InterruptedException e) {
        // continue
      }
      if(LOG.isDebugEnabled()) {
        LOG.debug("Wake. Waiting for first region to be disabled from " + tableName);
      }
    }
    LOG.info("Disabled table " + tableName);
  }
  public synchronized void shutdown() throws IOException {
@ -477,8 +484,8 @@ public class HClient implements HConstants {
    }
  }
-  private TableInfo getFirstMetaServerForTable(Text tableName) throws IOException {
+  private RegionLocation getFirstMetaServerForTable(Text tableName) throws IOException {
-    SortedMap<Text, TableInfo> metaservers = findMetaServersForTable(tableName);
+    SortedMap<Text, RegionLocation> metaservers = findMetaServersForTable(tableName);
    return metaservers.get(metaservers.firstKey());
  }
@ -497,7 +504,10 @@ public class HClient implements HConstants {
      throw new IllegalArgumentException("table name cannot be null or zero length");
    }
    this.tableServers = tablesToServers.get(tableName);
-    if(this.tableServers == null ) {
+    if (this.tableServers == null ) {
      if (LOG.isDebugEnabled()) {
        LOG.debug("No servers for " + tableName + ". Doing a find...");
      }
      // We don't know where the table is.
      // Load the information from meta.
      this.tableServers = findServersForTable(tableName);
@ -511,23 +521,25 @@ public class HClient implements HConstants {
   * @return - map of first row to table info for all regions in the table
   * @throws IOException
   */
-  private SortedMap<Text, TableInfo> findServersForTable(Text tableName)
+  private SortedMap<Text, RegionLocation> findServersForTable(Text tableName)
      throws IOException {
-
+    SortedMap<Text, RegionLocation> servers = null;
    SortedMap<Text, TableInfo> servers = null;
    if(tableName.equals(ROOT_TABLE_NAME)) {
      servers = locateRootRegion();
    } else if(tableName.equals(META_TABLE_NAME)) {
      servers = loadMetaFromRoot();
    } else {
-      servers = new TreeMap<Text, TableInfo>();
+      servers = new TreeMap<Text, RegionLocation>();
-      for(TableInfo t: findMetaServersForTable(tableName).values()) {
+      for(RegionLocation t: findMetaServersForTable(tableName).values()) {
        servers.putAll(scanOneMetaRegion(t, tableName));
      }
      this.tablesToServers.put(tableName, servers);
    }
    if (LOG.isDebugEnabled()) {
      for (Map.Entry<Text, RegionLocation> e: servers.entrySet()) {
        LOG.debug("Server " + e.getKey() + " is serving: " + e.getValue());
      }
    }
    return servers;
  }
@ -537,18 +549,15 @@ public class HClient implements HConstants {
   * @return - returns a SortedMap of the meta servers
   * @throws IOException
   */
-  private SortedMap<Text, TableInfo> findMetaServersForTable(Text tableName)
+  private SortedMap<Text, RegionLocation> findMetaServersForTable(final Text tableName)
  throws IOException {
-    
+    SortedMap<Text, RegionLocation> metaServers =
    SortedMap<Text, TableInfo> metaServers = 
      this.tablesToServers.get(META_TABLE_NAME);
    if(metaServers == null) {                 // Don't know where the meta is
      metaServers = loadMetaFromRoot();
    }
    Text firstMetaRegion = (metaServers.containsKey(tableName)) ?
      tableName : metaServers.headMap(tableName).lastKey();
    return metaServers.tailMap(firstMetaRegion);
  }
@ -558,10 +567,9 @@ public class HClient implements HConstants {
   * @return map of first row to TableInfo for all meta regions
   * @throws IOException
   */
-  private TreeMap<Text, TableInfo> loadMetaFromRoot() throws IOException {
+  private TreeMap<Text, RegionLocation> loadMetaFromRoot() throws IOException {
-    SortedMap<Text, TableInfo> rootRegion =
+    SortedMap<Text, RegionLocation> rootRegion =
      this.tablesToServers.get(ROOT_TABLE_NAME);
    if(rootRegion == null) {
      rootRegion = locateRootRegion();
    }
@ -570,34 +578,34 @@ public class HClient implements HConstants {
  /*
   * Repeatedly try to find the root region by asking the master for where it is
   * 
   * @return TreeMap<Text, TableInfo> for root regin if found
   * @throws NoServerForRegionException - if the root region can not be located after retrying
   * @throws IOException 
   */
-  private TreeMap<Text, TableInfo> locateRootRegion() throws IOException {
+  private TreeMap<Text, RegionLocation> locateRootRegion() throws IOException {
    checkMaster();
    HServerAddress rootRegionLocation = null;
-    for(int tries = 0; rootRegionLocation == null && tries < numRetries; tries++){
+    for(int tries = 0; tries < numRetries; tries++) {
      int localTimeouts = 0;
-      while(rootRegionLocation == null && localTimeouts < numTimeouts) {
+      while(rootRegionLocation == null && localTimeouts < numRetries) {
        rootRegionLocation = master.findRootRegion();
        if(rootRegionLocation == null) {
          try {
            if (LOG.isDebugEnabled()) {
              LOG.debug("Sleeping. Waiting for root region.");
            }
-            Thread.sleep(this.clientTimeout);
+            Thread.sleep(this.pause);
            if (LOG.isDebugEnabled()) {
              LOG.debug("Wake. Retry finding root region.");
            }
          } catch(InterruptedException iex) {
            // continue
          }
          localTimeouts++;
        }
      }
      if(rootRegionLocation == null) {
        throw new NoServerForRegionException(
            "Timed out trying to locate root region");
@ -608,7 +616,6 @@ public class HClient implements HConstants {
      try {
        rootRegion.getRegionInfo(HGlobals.rootRegionInfo.regionName);
        break;
      } catch(NotServingRegionException e) {
        if(tries == numRetries - 1) {
          // Don't bother sleeping. We've run out of retries.
@ -616,16 +623,16 @@ public class HClient implements HConstants {
        }
        // Sleep and retry finding root region.
        try {
          if (LOG.isDebugEnabled()) {
            LOG.debug("Root region location changed. Sleeping.");
          }
-          Thread.sleep(this.clientTimeout);
+          Thread.sleep(this.pause);
          if (LOG.isDebugEnabled()) {
            LOG.debug("Wake. Retry finding root region.");
          }
        } catch(InterruptedException iex) {
          // continue
        }
      }
      rootRegionLocation = null;
@ -636,9 +643,9 @@ public class HClient implements HConstants {
        "unable to locate root region server");
    }
-    TreeMap<Text, TableInfo> rootServer = new TreeMap<Text, TableInfo>();
+    TreeMap<Text, RegionLocation> rootServer = new TreeMap<Text, RegionLocation>();
    rootServer.put(EMPTY_START_ROW,
-        new TableInfo(HGlobals.rootRegionInfo, rootRegionLocation));
+        new RegionLocation(HGlobals.rootRegionInfo, rootRegionLocation));
    this.tablesToServers.put(ROOT_TABLE_NAME, rootServer);
    return rootServer;
@ -649,10 +656,9 @@ public class HClient implements HConstants {
   * @return - TreeMap of meta region servers
   * @throws IOException
   */
-  private TreeMap<Text, TableInfo> scanRoot(TableInfo rootRegion)
+  private TreeMap<Text, RegionLocation> scanRoot(RegionLocation rootRegion)
      throws IOException {
-    
+    TreeMap<Text, RegionLocation> metaservers =
    TreeMap<Text, TableInfo> metaservers =
      scanOneMetaRegion(rootRegion, META_TABLE_NAME);
    this.tablesToServers.put(META_TABLE_NAME, metaservers);
    return metaservers;
@ -663,16 +669,16 @@ public class HClient implements HConstants {
   * @param t the meta region we're going to scan
   * @param tableName the name of the table we're looking for
   * @return returns a map of startingRow to TableInfo
-   * @throws NoSuchElementException - if table does not exist
+   * @throws RegionNotFoundException - if table does not exist
   * @throws IllegalStateException - if table is offline
   * @throws NoServerForRegionException - if table can not be found after retrying
   * @throws IOException 
   */
-  private TreeMap<Text, TableInfo> scanOneMetaRegion(TableInfo t, Text tableName)
+  private TreeMap<Text, RegionLocation> scanOneMetaRegion(final RegionLocation t,
    final Text tableName)
  throws IOException {
    HRegionInterface server = getHRegionConnection(t.serverAddress);
-    TreeMap<Text, TableInfo> servers = new TreeMap<Text, TableInfo>();
+    TreeMap<Text, RegionLocation> servers = new TreeMap<Text, RegionLocation>();
    for(int tries = 0; servers.size() == 0 && tries < this.numRetries;
        tries++) {
@ -690,13 +696,15 @@ public class HClient implements HConstants {
          if(values.length == 0) {
            if(servers.size() == 0) {
              // If we didn't find any servers then the table does not exist
-
+              throw new RegionNotFoundException("table '" + tableName +
-              throw new NoSuchElementException("table '" + tableName
+                "' does not exist in " + t);
                  + "' does not exist");
            }
            // We found at least one server for the table and now we're done.
-
+            if (LOG.isDebugEnabled()) {
              LOG.debug("Found " + servers.size() + " server(s) for " +
                "location: " + t + " for tablename " + tableName);
            }
            break;
          }
@ -714,6 +722,9 @@ public class HClient implements HConstants {
          if(!regionInfo.tableDesc.getName().equals(tableName)) {
            // We're done
            if (LOG.isDebugEnabled()) {
              LOG.debug("Found " + tableName);
            }
            break;
          }
@ -724,7 +735,6 @@ public class HClient implements HConstants {
          bytes = results.get(COL_SERVER);
          if(bytes == null || bytes.length == 0) {
            // We need to rescan because the table we want is unassigned.
            if(LOG.isDebugEnabled()) {
              LOG.debug("no server address for " + regionInfo.toString());
            }
@ -732,15 +742,13 @@ public class HClient implements HConstants {
            break;
          }
          serverAddress = new String(bytes, UTF8_ENCODING);
          servers.put(regionInfo.startKey, 
-              new TableInfo(regionInfo, new HServerAddress(serverAddress)));
+              new RegionLocation(regionInfo, new HServerAddress(serverAddress)));
        }
      } finally {
        if(scannerId != -1L) {
          try {
            server.close(scannerId);
          } catch(Exception e) {
            LOG.warn(e);
          }
@ -752,21 +760,22 @@ public class HClient implements HConstants {
            + tableName + " after " + this.numRetries + " retries");
      }
      if (servers.size() <= 0) {
        // The table is not yet being served. Sleep and retry.
-
+        if (LOG.isDebugEnabled()) {
-      if(LOG.isDebugEnabled()) {
+          LOG.debug("Sleeping. Table " + tableName +
-        LOG.debug("Sleeping. Table " + tableName
+            " not currently being served.");
            + " not currently being served.");
        }
        try {
-        Thread.sleep(this.clientTimeout);
+          Thread.sleep(this.pause);
-
+        } catch (InterruptedException e) {
-      } catch(InterruptedException e) {
+          // continue
        }
-      if(LOG.isDebugEnabled()) {
+        if (LOG.isDebugEnabled()) {
          LOG.debug("Wake. Retry finding table " + tableName);
        }
      }
    }
    return servers;
  }
@ -804,7 +813,7 @@ public class HClient implements HConstants {
      throws IOException {
    TreeSet<HTableDescriptor> uniqueTables = new TreeSet<HTableDescriptor>();
-    SortedMap<Text, TableInfo> metaTables =
+    SortedMap<Text, RegionLocation> metaTables =
      this.tablesToServers.get(META_TABLE_NAME);
    if(metaTables == null) {
@ -812,7 +821,7 @@ public class HClient implements HConstants {
      metaTables = loadMetaFromRoot();
    }
-    for (TableInfo t: metaTables.values()) {
+    for (RegionLocation t: metaTables.values()) {
      HRegionInterface server = getHRegionConnection(t.serverAddress);
      long scannerId = -1L;
      try {
@ -846,11 +855,15 @@ public class HClient implements HConstants {
        }
      }
    }
-    return (HTableDescriptor[])uniqueTables.
+    return uniqueTables.toArray(new HTableDescriptor[uniqueTables.size()]);
      toArray(new HTableDescriptor[uniqueTables.size()]);
  }
-  private synchronized TableInfo getTableInfo(Text row) {
+  /*
   * Find region location hosting passed row using cached info
   * @param row Row to find.
   * @return Location of row.
   */
  synchronized RegionLocation getRegionLocation(Text row) {
    if(row == null || row.getLength() == 0) {
      throw new IllegalArgumentException("row key cannot be null or zero length");
    }
@ -859,41 +872,42 @@ public class HClient implements HConstants {
    }
    // Only one server will have the row we are looking for
-    
+    Text serverKey = (this.tableServers.containsKey(row))? row:
-    Text serverKey = null;
+      this.tableServers.headMap(row).lastKey();
    if(this.tableServers.containsKey(row)) {
      serverKey = row;
    } else {
      serverKey = this.tableServers.headMap(row).lastKey();
    }
    return this.tableServers.get(serverKey);
  }
-  private synchronized void findRegion(TableInfo info) throws IOException {
+  /*
-    
+   * Clear caches of passed region location, reload servers for the passed
   * region's table and then ensure region location can be found.
   * @param info Region location to find.
   * @throws IOException
   */
  synchronized void findRegion(final RegionLocation info) throws IOException {
    // Wipe out everything we know about this table
-    
+    if (LOG.isDebugEnabled()) {
      LOG.debug("Wiping out all we know of " + info);
    }
    this.tablesToServers.remove(info.regionInfo.tableDesc.getName());
    this.tableServers.clear();
    // Reload information for the whole table
    this.tableServers = findServersForTable(info.regionInfo.tableDesc.getName());
-    
+    if (LOG.isDebugEnabled()) {
-    if(this.tableServers.get(info.regionInfo.startKey) == null ) {
+      LOG.debug("Result of findRegion: " + this.tableServers.toString());
-      throw new IOException("region " + info.regionInfo.regionName
+    }
-          + " does not exist");
+    if (this.tableServers.get(info.regionInfo.startKey) == null) {
      throw new RegionNotFoundException(info.regionInfo.regionName.toString());
    }
  }
  /** Get a single value for the specified row and column */
  public byte[] get(Text row, Text column) throws IOException {
-    TableInfo info = null;
+    RegionLocation info = null;
    BytesWritable value = null;
    for(int tries = 0; tries < numRetries && info == null; tries++) {
-      info = getTableInfo(row);
+      info = getRegionLocation(row);
      try {
        value = getHRegionConnection(info.serverAddress).get(
@ -919,11 +933,11 @@ public class HClient implements HConstants {
  /** Get the specified number of versions of the specified row and column */
  public byte[][] get(Text row, Text column, int numVersions) throws IOException {
-    TableInfo info = null;
+    RegionLocation info = null;
    BytesWritable[] values = null;
    for(int tries = 0; tries < numRetries && info == null; tries++) {
-      info = getTableInfo(row);
+      info = getRegionLocation(row);
      try {
        values = getHRegionConnection(info.serverAddress).get(
@ -956,11 +970,11 @@ public class HClient implements HConstants {
   * the specified timestamp.
   */
  public byte[][] get(Text row, Text column, long timestamp, int numVersions) throws IOException {
-    TableInfo info = null;
+    RegionLocation info = null;
    BytesWritable[] values = null;
    for(int tries = 0; tries < numRetries && info == null; tries++) {
-      info = getTableInfo(row);
+      info = getRegionLocation(row);
      try {
        values = getHRegionConnection(info.serverAddress).get(
@ -990,11 +1004,11 @@ public class HClient implements HConstants {
  /** Get all the data for the specified row */
  public LabelledData[] getRow(Text row) throws IOException {
-    TableInfo info = null;
+    RegionLocation info = null;
    LabelledData[] value = null;
    for(int tries = 0; tries < numRetries && info == null; tries++) {
-      info = getTableInfo(row);
+      info = getRegionLocation(row);
      try {
        value = getHRegionConnection(info.serverAddress).getRow(
@ -1024,37 +1038,80 @@ public class HClient implements HConstants {
    return new ClientScanner(columns, startRow);
  }
-  /** Start an atomic row insertion or update */
+  /*
-  public long startUpdate(Text row) throws IOException {
+   * @return General HClient RetryPolicy instance.
-    TableInfo info = null;
+   */
-    long lockid = -1L;
+  RetryPolicy getRetryPolicy() {
    Map<Class <? extends Exception>, RetryPolicy> exceptionToPolicyMap =
      new HashMap<Class <? extends Exception>, RetryPolicy>();
    // Pass numRetries - 1 because it does less-than-equal internally rather
    // than the less-than we do elsewhere where we use numRetries.
    RetryPolicy rp =
      RetryPolicies.retryUpToMaximumCountWithProportionalSleep(numRetries,
        this.pause, TimeUnit.MILLISECONDS);
    exceptionToPolicyMap.put(NotServingRegionException.class, rp);
    exceptionToPolicyMap.put(WrongRegionException.class, rp);
    exceptionToPolicyMap.put(RegionNotFoundException.class, rp);
    return RetryPolicies.retryByRemoteException(RetryPolicies.TRY_ONCE_THEN_FAIL,
      exceptionToPolicyMap);
-    for(int tries = 0; tries < numRetries && info == null; tries++) {
+  }
      info = getTableInfo(row);
  /*
   * Interface for {@link #startUpate()} used by the
   * {@link org.apache.hadoop.io.retry} mechanism. 
   */
  private interface StartUpdateInterface {
    /**
     * @return row lockid for the update
     * @throws IOException
     */
    long startUpdate() throws IOException;
  }
  /* Start an atomic row insertion or update
   * @param row Name of row to start update against.
   * @return Row lockid.
   */
  public long startUpdate(final Text row) throws IOException {
    // Implemention of the StartUpdate interface.
    StartUpdateInterface implementation = new StartUpdateInterface() {
      private RegionLocation info = null;
      private int attempts = 0;
      /*
       * Wrapped method.  Proxy wrapper is configured to judge whether
       * exception merits retry.
       * @return lockid
       * @throws IOException
       */
      public long startUpdate() throws IOException {
        this.attempts++;
        if (this.info != null) {
          LOG.info("Retry of startUpdate.  Attempt " + this.attempts +
            " for row " + row);
          // If a retry. Something wrong w/ region we have. Refind.
          try {
        this.currentServer = getHRegionConnection(info.serverAddress);
        this.currentRegion = info.regionInfo.regionName;
        this.clientid = rand.nextLong();
        lockid = currentServer.startUpdate(this.currentRegion, this.clientid, row);
      } catch(NotServingRegionException e) {
        if(tries == numRetries - 1) {
          // No more tries
          throw e;
        }
            findRegion(info);
-        info = null;
+          } catch (RegionNotFoundException e) {
-
+            // continue.  If no longer exists, perhaps we just came through
-      } catch(IOException e) {
+            // a split and region is now gone. Below getRegionLocation should
-        this.currentServer = null;
+            // recalibrate client.
        this.currentRegion = null;
        throw e;
          }
        }
        this.info = getRegionLocation(row);
        currentServer = getHRegionConnection(info.serverAddress);
        currentRegion = info.regionInfo.regionName;
        clientid = rand.nextLong();
        return currentServer.startUpdate(currentRegion, clientid, row);
      }
    };
-    return lockid;
+    // Get retry proxy wrapper around 'implementation'.
    StartUpdateInterface retryProxy = (StartUpdateInterface)RetryProxy.
      create(StartUpdateInterface.class, implementation, getRetryPolicy());
    // Run retry.
    return retryProxy.startUpdate();
  }
  /** Change a value for the specified column */
@ -1062,12 +1119,11 @@ public class HClient implements HConstants {
    try {
      this.currentServer.put(this.currentRegion, this.clientid, lockid, column,
          new BytesWritable(val));
    } catch(IOException e) {
      try {
        this.currentServer.abort(this.currentRegion, this.clientid, lockid);
      } catch(IOException e2) {
        LOG.warn(e2);
      }
      this.currentServer = null;
      this.currentRegion = null;
@ -1078,13 +1134,13 @@ public class HClient implements HConstants {
  /** Delete the value for a column */
  public void delete(long lockid, Text column) throws IOException {
    try {
-      this.currentServer.delete(this.currentRegion, this.clientid, lockid, column);
+      this.currentServer.delete(this.currentRegion, this.clientid, lockid,
-      
+        column);
    } catch(IOException e) {
      try {
        this.currentServer.abort(this.currentRegion, this.clientid, lockid);
      } catch(IOException e2) {
        LOG.warn(e2);
      }
      this.currentServer = null;
      this.currentRegion = null;
@ -1107,7 +1163,6 @@ public class HClient implements HConstants {
  public void commit(long lockid) throws IOException {
    try {
      this.currentServer.commit(this.currentRegion, this.clientid, lockid);
    } finally {
      this.currentServer = null;
      this.currentRegion = null;
@ -1123,7 +1178,7 @@ public class HClient implements HConstants {
    private Text[] columns;
    private Text startRow;
    private boolean closed;
-    private TableInfo[] regions;
+    private RegionLocation[] regions;
    private int currentRegion;
    private HRegionInterface server;
    private long scannerId;
@ -1139,8 +1194,8 @@ public class HClient implements HConstants {
      } else {
        firstServer = tableServers.headMap(startRow).lastKey();
      }
-      Collection<TableInfo> info = tableServers.tailMap(firstServer).values();
+      Collection<RegionLocation> info = tableServers.tailMap(firstServer).values();
-      this.regions = info.toArray(new TableInfo[info.size()]);
+      this.regions = info.toArray(new RegionLocation[info.size()]);
    }
    public ClientScanner(Text[] columns, Text startRow) throws IOException {
@ -1173,7 +1228,7 @@ public class HClient implements HConstants {
        this.server = getHRegionConnection(this.regions[currentRegion].serverAddress);
        for(int tries = 0; tries < numRetries; tries++) {
-          TableInfo info = this.regions[currentRegion];
+          RegionLocation info = this.regions[currentRegion];
          try {
            this.scannerId = this.server.openScanner(info.regionInfo.regionName,
@ -1247,15 +1302,37 @@ public class HClient implements HConstants {
    System.err.println("              address is read from configuration.");
    System.err.println("Commands:");
    System.err.println(" shutdown     Shutdown the HBase cluster.");
-    System.err.println(" createTable  Takes table name, column families,... ");
+    System.err.println(" createTable  Create named table.");
-    System.err.println(" deleteTable  Takes a table name.");
+    System.err.println(" deleteTable  Delete named table.");
-    System.err.println(" iistTables   List all tables.");
+    System.err.println(" listTables   List all tables.");
    System.err.println("Example Usage:");
    System.err.println(" % java " + this.getClass().getName() + " shutdown");
    System.err.println(" % java " + this.getClass().getName() +
        " createTable webcrawl contents: anchors: 10");
  }
  private void printCreateTableUsage(final String message) {
    if (message != null && message.length() > 0) {
      System.err.println(message);
    }
    System.err.println("Usage: java " + this.getClass().getName() +
      " [options] createTable <name> <colfamily1> ... <max_versions>");
    System.err.println("Example Usage:");
    System.err.println(" % java " + this.getClass().getName() +
      " createTable testtable column_x column_y column_z 3");
  }
  private void printDeleteTableUsage(final String message) {
    if (message != null && message.length() > 0) {
      System.err.println(message);
    }
    System.err.println("Usage: java " + this.getClass().getName() +
      " [options] deleteTable <name>");
    System.err.println("Example Usage:");
    System.err.println(" % java " + this.getClass().getName() +
      " deleteTable testtable");
  }
  public int doCommandLine(final String args[]) {
    // Process command-line args. TODO: Better cmd-line processing
    // (but hopefully something not as painful as cli options).    
@ -1296,8 +1373,10 @@ public class HClient implements HConstants {
        if (cmd.equals("createTable")) {
          if (i + 2 > args.length) {
-            throw new IllegalArgumentException("Must supply a table name " +
+            printCreateTableUsage("Error: Supply a table name," +
-              "and at least one column family");
+              " at least one column family, and maximum versions");
            errCode = 1;
            break;
          }
          HTableDescriptor desc = new HTableDescriptor(args[i + 1]);
          boolean addedFamily = false;
@ -1316,7 +1395,9 @@ public class HClient implements HConstants {
        if (cmd.equals("deleteTable")) {
          if (i + 1 > args.length) {
-            throw new IllegalArgumentException("Must supply a table name");
+            printDeleteTableUsage("Error: Must supply a table name");
            errCode = 1;
            break;
          }
          deleteTable(new Text(args[i + 1]));
          errCode = 0;
--- a/src/java/org/apache/hadoop/hbase/HConstants.java
+++ b/src/java/org/apache/hadoop/hbase/HConstants.java
@ -50,6 +50,8 @@ public interface HConstants {
  // do, it will clash with the HREGION log dir subdirectory. FIX.
  static final String HREGION_LOGDIR_NAME = "log";
  static final long DEFAULT_MAX_FILE_SIZE = 128 * 1024 * 1024;        // 128MB
  // Always store the location of the root table's HRegion.
  // This HRegion is never split.
@ -72,7 +74,6 @@ public interface HConstants {
  // Other constants
  static final long DESIRED_MAX_FILE_SIZE = 128 * 1024 * 1024;        // 128MB
  static final String UTF8_ENCODING = "UTF-8";
  static final BytesWritable DELETE_BYTES = 
--- a/src/java/org/apache/hadoop/hbase/HMaster.java
+++ b/src/java/org/apache/hadoop/hbase/HMaster.java
@ -50,7 +50,8 @@ import org.apache.hadoop.util.StringUtils;
 public class HMaster implements HConstants, HMasterInterface, 
    HMasterRegionInterface, Runnable {
-  public long getProtocolVersion(String protocol, long clientVersion)
+  public long getProtocolVersion(String protocol,
    @SuppressWarnings("unused") long clientVersion)
  throws IOException { 
    if (protocol.equals(HMasterInterface.class.getName())) {
      return HMasterInterface.versionID; 
@ -61,43 +62,41 @@ public class HMaster implements HConstants, HMasterInterface,
    }
  }
-  private static final Log LOG =
+  static final Log LOG =
    LogFactory.getLog(org.apache.hadoop.hbase.HMaster.class.getName());
-  private volatile boolean closed;
+  volatile boolean closed;
-  private Path dir;
+  Path dir;
  private Configuration conf;
-  private FileSystem fs;
+  FileSystem fs;
-  private Random rand;
+  Random rand;
  private long threadWakeFrequency; 
  private int numRetries;
  private long maxRegionOpenTime;
-  // The 'msgQueue' is used to assign work to the client processor thread
+  Vector<PendingOperation> msgQueue;
  private Vector<PendingOperation> msgQueue;
  private Leases serverLeases;
  private Server server;
  private HServerAddress address;
-  private HClient client;
+  HClient client;
-  private long metaRescanInterval;
+  long metaRescanInterval;
  private HServerAddress rootRegionLocation;
  /**
   * Columns in the 'meta' ROOT and META tables.
   */
-  private static final Text METACOLUMNS[] = {
+  static final Text METACOLUMNS[] = {
      COLUMN_FAMILY
  };
  static final String MASTER_NOT_RUNNING = "Master not running";
-  private boolean rootScanned;
+  boolean rootScanned;
-  private int numMetaRegions;
+  int numMetaRegions;
  /**
   * Base HRegion scanner class. Holds utilty common to <code>ROOT</code> and
@ -146,116 +145,80 @@ public class HMaster implements HConstants, HMasterInterface,
   * <p>A <code>META</code> region is not 'known' until it has been scanned
   * once.
   */
-  private abstract class BaseScanner implements Runnable {
+  abstract class BaseScanner implements Runnable {
    private final Text FIRST_ROW = new Text();
    /**
     * @param region Region to scan
     * @return True if scan completed.
     * @throws IOException
     */
    protected boolean scanRegion(final MetaRegion region)
    throws IOException {
      boolean scannedRegion = false;
-      HRegionInterface server = null;
+      HRegionInterface regionServer = null;
      long scannerId = -1L;
      if (LOG.isDebugEnabled()) {
-        LOG.debug("scanning meta region " + region.regionName);
+        LOG.debug(Thread.currentThread().getName() + " scanning meta region " +
          region.regionName);
      }
      try {
-        server = client.getHRegionConnection(region.server);
+        regionServer = client.getHRegionConnection(region.server);
-        scannerId = server.openScanner(region.regionName, METACOLUMNS, FIRST_ROW);
+        scannerId = regionServer.openScanner(region.regionName, METACOLUMNS,
-
+          FIRST_ROW);
        DataInputBuffer inbuf = new DataInputBuffer();
        while (true) {
          TreeMap<Text, byte[]> results = new TreeMap<Text, byte[]>();
          HStoreKey key = new HStoreKey();
-
+          LabelledData[] values = regionServer.next(scannerId, key);
          LabelledData[] values = server.next(scannerId, key);
          if (values.length == 0) {
            break;
          }
          for (int i = 0; i < values.length; i++) {
            byte[] bytes = new byte[values[i].getData().getSize()];
-            System.arraycopy(values[i].getData().get(), 0, bytes, 0, bytes.length);
+            System.arraycopy(values[i].getData().get(), 0, bytes, 0,
              bytes.length);
            results.put(values[i].getLabel(), bytes);
          }
-          HRegionInfo info = getRegionInfo(COL_REGIONINFO, results, inbuf);
+          HRegionInfo info = HRegion.getRegionInfo(results);
-          String serverName = getServerName(COL_SERVER, results);
+          String serverName = HRegion.getServerName(results);
-          long startCode = getStartCode(COL_STARTCODE, results);
+          long startCode = HRegion.getStartCode(results);
          if(LOG.isDebugEnabled()) {
-            LOG.debug("row: " + info.toString() + ", server: " + serverName
+            LOG.debug(Thread.currentThread().getName() + " scanner: " +
-                + ", startCode: " + startCode);
+              Long.valueOf(scannerId) + " regioninfo: {" + info.toString() +
              "}, server: " + serverName + ", startCode: " + startCode);
          }
          // Note Region has been assigned.
          checkAssigned(info, serverName, startCode);
          scannedRegion = true;
        }
      } catch (UnknownScannerException e) {
        // Reset scannerId so we do not try closing a scanner the other side
        // has lost account of: prevents duplicated stack trace out of the 
        // below close in the finally.
        scannerId = -1L;
      } finally {
        try {
          if (scannerId != -1L) {
-            server.close(scannerId);
+            if (regionServer != null) {
              regionServer.close(scannerId);
            }
          }
        } catch (IOException e) {
          LOG.error(e);
        }
        scannerId = -1L;
      }
      if (LOG.isDebugEnabled()) {
-        LOG.debug("scan of meta region " + region.regionName + " complete");
+        LOG.debug(Thread.currentThread().getName() + " scan of meta region " +
          region.regionName + " complete");
      }
      return scannedRegion;
    }
    protected HRegionInfo getRegionInfo(final Text key,
        final TreeMap<Text, byte[]> data, final DataInputBuffer in)
    throws IOException {
      byte[] bytes = data.get(key);
      if (bytes == null || bytes.length == 0) {
        throw new IOException("no value for " + key);
      }
      in.reset(bytes, bytes.length);
      HRegionInfo info = new HRegionInfo();
      info.readFields(in);
      return info;
    }
    protected String getServerName(final Text key,
        final TreeMap<Text, byte[]> data) {
      byte [] bytes = data.get(key);
      String name = null;
      try {
        name = (bytes != null && bytes.length != 0) ?
            new String(bytes, UTF8_ENCODING): null;
      } catch(UnsupportedEncodingException e) {
        assert(false);
      }
      return (name != null)? name.trim(): name;
    }
    protected long getStartCode(final Text key,
        final TreeMap<Text, byte[]> data) {
      long startCode = -1L;
      byte [] bytes = data.get(key);
      if(bytes != null && bytes.length != 0) {
        try {
          startCode = Long.valueOf(new String(bytes, UTF8_ENCODING).trim());
        } catch(NumberFormatException e) {
          assert(false);
        } catch(UnsupportedEncodingException e) {
          assert(false);
        }
      }
      return startCode;
    }
    protected void checkAssigned(final HRegionInfo info,
        final String serverName, final long startCode) {
@ -327,23 +290,17 @@ public class HMaster implements HConstants, HMasterInterface,
            rootScanned = true;
          }
          try {
            if (LOG.isDebugEnabled()) {
              LOG.debug("RootScanner going to sleep");
            }
            Thread.sleep(metaRescanInterval);
            if (LOG.isDebugEnabled()) {
              LOG.debug("RootScanner woke up");
            }
          } catch(InterruptedException e) {
            // Catch and go around again. If interrupt, its spurious or we're
            // being shutdown.  Go back up to the while test.
          }
        }
      } catch(IOException e) {
-        LOG.error(e);
+        LOG.error("ROOT scanner", e);
        closed = true;
      }
-      LOG.debug("ROOT scanner exiting");
+      LOG.info("ROOT scanner exiting");
    }
  }
@ -369,7 +326,6 @@ public class HMaster implements HConstants, HMasterInterface,
    }
    // Comparable
    public int compareTo(Object o) {
      MetaRegion other = (MetaRegion)o;
@ -383,11 +339,11 @@ public class HMaster implements HConstants, HMasterInterface,
  }
  /** Work for the meta scanner is queued up here */
-  private Vector<MetaRegion> metaRegionsToScan;
+  Vector<MetaRegion> metaRegionsToScan;
-  private SortedMap<Text, MetaRegion> knownMetaRegions;
+  SortedMap<Text, MetaRegion> knownMetaRegions;
-  private boolean allMetaRegionsScanned;
+  boolean allMetaRegionsScanned;
  /**
   * MetaScanner <code>META</code> table.
@ -399,6 +355,7 @@ public class HMaster implements HConstants, HMasterInterface,
   * action would prevent other work from getting done.
   */
  private class MetaScanner extends BaseScanner {
    @SuppressWarnings("null")
    public void run() {
      while (!closed) {
        if (LOG.isDebugEnabled()) {
@ -412,13 +369,7 @@ public class HMaster implements HConstants, HMasterInterface,
            }
            if (region == null) {
              try {
                if (LOG.isDebugEnabled()) {
                  LOG.debug("MetaScanner going into wait");
                }
                metaRegionsToScan.wait();
                if (LOG.isDebugEnabled()) {
                  LOG.debug("MetaScanner woke up");
                }
              } catch (InterruptedException e) {
                // Catch and go around again.  We've been woken because there
                // are new meta regions available or because we are being
@ -445,13 +396,7 @@ public class HMaster implements HConstants, HMasterInterface,
          do {
            try {
              if (LOG.isDebugEnabled()) {
                LOG.debug("Sleep for meta rescan interval");
              }
              Thread.sleep(metaRescanInterval);
              if (LOG.isDebugEnabled()) {
                LOG.debug("Sleep for meta rescan interval");
              }
            } catch(InterruptedException ex) {
              // Catch and go around again.
            }
@ -472,13 +417,11 @@ public class HMaster implements HConstants, HMasterInterface,
          } while(true);
        } catch(IOException e) {
-          LOG.error(e);
+          LOG.error("META scanner", e);
          closed = true;
        }
      }
-      if(LOG.isDebugEnabled()) {
+      LOG.info("META scanner exiting");
        LOG.debug("META scanner exiting");
      }
    }
    private synchronized void metaRegionsScanned() {
@ -488,25 +431,17 @@ public class HMaster implements HConstants, HMasterInterface,
    public synchronized void waitForMetaScan() {
      while(!closed && !allMetaRegionsScanned) {
        try {
          if (LOG.isDebugEnabled()) {
            LOG.debug("Wait for all meta regions scanned");
          }
          wait();
          if (LOG.isDebugEnabled()) {
            LOG.debug("Wake from wait for all meta regions scanned");
          }
        } catch(InterruptedException e) {
-          if (LOG.isDebugEnabled()) {
+          // continue
            LOG.debug("Wake from wait for all meta regions scanned (IE)");
          }
        }
      }
    }
  }
-  private MetaScanner metaScanner;
+  MetaScanner metaScanner;
  private Thread metaScannerThread;
-  private Integer metaScannerLock = 0;
+  Integer metaScannerLock = 0;
  // The 'unassignedRegions' table maps from a region name to a HRegionInfo record,
  // which includes the region's table, its id, and its start/end keys.
@ -514,31 +449,28 @@ public class HMaster implements HConstants, HMasterInterface,
  // We fill 'unassignedRecords' by scanning ROOT and META tables, learning the 
  // set of all known valid regions.
-  private SortedMap<Text, HRegionInfo> unassignedRegions;
+  SortedMap<Text, HRegionInfo> unassignedRegions;
  // The 'assignAttempts' table maps from regions to a timestamp that indicates 
  // the last time we *tried* to assign the region to a RegionServer. If the 
  // timestamp is out of date, then we can try to reassign it.
-  private SortedMap<Text, Long> assignAttempts;
+  SortedMap<Text, Long> assignAttempts;
-  // 'killList' indicates regions that we hope to close and not reopen 
+  SortedMap<String, TreeMap<Text, HRegionInfo>> killList;
  // (because we're merging them, or taking the table offline, for example).
  private SortedMap<String, TreeMap<Text, HRegionInfo>> killList;
  // 'killedRegions' contains regions that are in the process of being closed
-  private SortedSet<Text> killedRegions;
+  SortedSet<Text> killedRegions;
  // 'regionsToDelete' contains regions that need to be deleted, but cannot be
  // until the region server closes it
-  private SortedSet<Text> regionsToDelete;
+  SortedSet<Text> regionsToDelete;
  // A map of known server names to server info
-  private SortedMap<String, HServerInfo> serversToServerInfo =
+  SortedMap<String, HServerInfo> serversToServerInfo =
    Collections.synchronizedSortedMap(new TreeMap<String, HServerInfo>());
  /** Build the HMaster out of a raw configuration item. */
@ -576,18 +508,16 @@ public class HMaster implements HConstants, HMasterInterface,
    if(! fs.exists(rootRegionDir)) {
      LOG.info("bootstrap: creating ROOT and first META regions");
      try {
-        HRegion root = HRegion.createNewHRegion(fs, dir, conf, 
+        HRegion root = HRegion.createHRegion(0L, HGlobals.rootTableDesc,
-            HGlobals.rootTableDesc, 0L, null, null);
+          this.dir, this.conf);
-        HRegion meta = HRegion.createNewHRegion(fs, dir, conf,
+        HRegion meta = HRegion.createHRegion(1L, HGlobals.metaTableDesc,
-            HGlobals.metaTableDesc, 1L, null, null);
+            this.dir, this.conf);
-      
+        // Add first region from the META table to the ROOT region.
-        HRegion.addRegionToMeta(root, meta);
+        HRegion.addRegionToMETA(root, meta);
        root.close();
        root.getLog().close();
        meta.close();
        meta.getLog().close();
      } catch(IOException e) {
        LOG.error(e);
      }
@ -690,6 +620,7 @@ public class HMaster implements HConstants, HMasterInterface,
          try {
            msgQueue.wait(threadWakeFrequency);
          } catch(InterruptedException iex) {
            // continue
          }
        }
        if(closed) {
@ -751,9 +682,7 @@ public class HMaster implements HConstants, HMasterInterface,
      LOG.warn(iex);
    }
-    if(LOG.isDebugEnabled()) {
+    LOG.info("HMaster main thread exiting");
      LOG.debug("HMaster main thread exiting");
    }
  }
  /**
@ -1085,7 +1014,7 @@ public class HMaster implements HConstants, HMasterInterface,
        }
      }
    }
-    return (HMsg[]) returnMsgs.toArray(new HMsg[returnMsgs.size()]);
+    return returnMsgs.toArray(new HMsg[returnMsgs.size()]);
  }
  private synchronized void rootRegionIsAvailable() {
@ -1195,8 +1124,8 @@ public class HMaster implements HConstants, HMasterInterface,
          long startCode = -1L;
          try {
-            startCode = Long.valueOf(new String(bytes, UTF8_ENCODING));
+            startCode = Long.valueOf(new String(bytes, UTF8_ENCODING)).
-
+              longValue();
          } catch(UnsupportedEncodingException e) {
            LOG.error(e);
            break;
@ -1558,7 +1487,7 @@ public class HMaster implements HConstants, HMasterInterface,
    }
  }
-  private synchronized void waitForRootRegion() {
+  synchronized void waitForRootRegion() {
    while (rootRegionLocation == null) {
      try {
        if (LOG.isDebugEnabled()) {
@ -1625,8 +1554,8 @@ public class HMaster implements HConstants, HMasterInterface,
        // 2. Create the HRegion
-        HRegion r = HRegion.createNewHRegion(fs, dir, conf, desc,
+        HRegion r = HRegion.createHRegion(newRegion.regionId, desc, this.dir,
-            newRegion.regionId, null, null);
+          this.conf);
        // 3. Insert into meta
@ -1874,7 +1803,6 @@ public class HMaster implements HConstants, HMasterInterface,
    protected boolean isBeingServed(String serverName, long startCode) {
      boolean result = false;
      if(serverName != null && startCode != -1L) {
        HServerInfo s = serversToServerInfo.get(serverName);
        result = s != null && s.getStartCode() == startCode;
@ -1890,28 +1818,29 @@ public class HMaster implements HConstants, HMasterInterface,
        HRegionInfo info) throws IOException;
    protected abstract void postProcessMeta(MetaRegion m,
-        HRegionInterface server) throws IOException;
+        HRegionInterface server)
    throws IOException;
  }
  private class ChangeTableState extends TableOperation {
    private boolean online;
-    protected TreeMap<String, TreeSet<HRegionInfo>> servedRegions;
+    protected TreeMap<String, TreeSet<HRegionInfo>> servedRegions =
      new TreeMap<String, TreeSet<HRegionInfo>>();
    protected long lockid;
    protected long clientId;
    public ChangeTableState(Text tableName, boolean onLine) throws IOException {
      super(tableName);
      this.online = onLine;
      this.servedRegions = new TreeMap<String, TreeSet<HRegionInfo>>();
    }
    protected void processScanItem(String serverName, long startCode,
-        HRegionInfo info) throws IOException {
+        HRegionInfo info)
-      
+    throws IOException {
-      if(isBeingServed(serverName, startCode)) {
+      if (isBeingServed(serverName, startCode)) {
        TreeSet<HRegionInfo> regions = servedRegions.get(serverName);
-        if(regions == null) {
+        if (regions == null) {
          regions = new TreeSet<HRegionInfo>();
        }
        regions.add(info);
@ -1921,16 +1850,12 @@ public class HMaster implements HConstants, HMasterInterface,
    protected void postProcessMeta(MetaRegion m, HRegionInterface server)
        throws IOException {
      // Process regions not being served
      if(LOG.isDebugEnabled()) {
        LOG.debug("processing unserved regions");
      }
      for(HRegionInfo i: unservedRegions) {
        // Update meta table
        if(LOG.isDebugEnabled()) {
          LOG.debug("updating columns in row: " + i.regionName);
        }
@ -1986,13 +1911,12 @@ public class HMaster implements HConstants, HMasterInterface,
      }
      for(Map.Entry<String, TreeSet<HRegionInfo>> e: servedRegions.entrySet()) {
        String serverName = e.getKey();
-        
+        if (online) {
-        if(online) {
+          LOG.debug("Already online");
          continue;                             // Already being served
        }
-        // Cause regions being served to be take off-line and disabled
+        // Cause regions being served to be taken off-line and disabled
        TreeMap<Text, HRegionInfo> localKillList = killList.get(serverName);
        if(localKillList == null) {
          localKillList = new TreeMap<Text, HRegionInfo>();
@ -2003,9 +1927,10 @@ public class HMaster implements HConstants, HMasterInterface,
          }
          localKillList.put(i.regionName, i);
        }
-        if(localKillList != null && localKillList.size() > 0) {
+        if(localKillList.size() > 0) {
          if(LOG.isDebugEnabled()) {
-            LOG.debug("inserted local kill list into kill list for server " + serverName);
+            LOG.debug("inserted local kill list into kill list for server " +
              serverName);
          }
          killList.put(serverName, localKillList);
        }
@ -2036,23 +1961,18 @@ public class HMaster implements HConstants, HMasterInterface,
    protected void postProcessMeta(MetaRegion m, HRegionInterface server)
        throws IOException {
      // For regions that are being served, mark them for deletion      
-      
+      for (TreeSet<HRegionInfo> s: servedRegions.values()) {
-      for(TreeSet<HRegionInfo> s: servedRegions.values()) {
+        for (HRegionInfo i: s) {
        for(HRegionInfo i: s) {
          regionsToDelete.add(i.regionName);
        }
      }
      // Unserved regions we can delete now
-      
+      for (HRegionInfo i: unservedRegions) {
      for(HRegionInfo i: unservedRegions) {
        // Delete the region
        try {
          HRegion.deleteRegion(fs, dir, i.regionName);
        } catch(IOException e) {
          LOG.error("failed to delete region " + i.regionName);
          LOG.error(e);
@ -2062,22 +1982,23 @@ public class HMaster implements HConstants, HMasterInterface,
    }
    @Override
-    protected void updateRegionInfo(HRegionInterface server, Text regionName,
+    protected void updateRegionInfo(
-        HRegionInfo i) throws IOException {
+      @SuppressWarnings("hiding") HRegionInterface server, Text regionName,
-      
+      @SuppressWarnings("unused") HRegionInfo i)
    throws IOException {
      server.delete(regionName, clientId, lockid, COL_REGIONINFO);
    }
  }
  private abstract class ColumnOperation extends TableOperation {
    protected ColumnOperation(Text tableName) throws IOException {
      super(tableName);
    }
-    protected void processScanItem(String serverName, long startCode,
+    protected void processScanItem(
-        HRegionInfo info) throws IOException {
+      @SuppressWarnings("unused") String serverName,
-      
+      @SuppressWarnings("unused") long startCode, final HRegionInfo info)
    throws IOException {  
      if(isEnabled(info)) {
        throw new TableNotDisabledException(tableName.toString());
      }
@ -2196,10 +2117,7 @@ public class HMaster implements HConstants, HMasterInterface,
    }
    public void leaseExpired() {
-      if(LOG.isDebugEnabled()) {
+      LOG.info(server + " lease expired");
        LOG.debug(server + " lease expired");
      }
      HServerInfo storedInfo = serversToServerInfo.remove(server);
      synchronized(msgQueue) {
        msgQueue.add(new PendingServerShutdown(storedInfo));
@ -2218,7 +2136,7 @@ public class HMaster implements HConstants, HMasterInterface,
    System.exit(0);
  }
-  public static void main(String [] args) throws IOException {
+  public static void main(String [] args) {
    if (args.length < 1) {
      printUsageAndExit();
    }
--- a/src/java/org/apache/hadoop/hbase/HMemcache.java
+++ b/src/java/org/apache/hadoop/hbase/HMemcache.java
@ -27,12 +27,12 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.io.BytesWritable;
 import org.apache.hadoop.io.Text;
-/*******************************************************************************
+/**
 * The HMemcache holds in-memory modifications to the HRegion.  This is really a
 * wrapper around a TreeMap that helps us when staging the Memcache out to disk.
- ******************************************************************************/
+ */
 public class HMemcache {
-  private static final Log LOG = LogFactory.getLog(HMemcache.class);
+  private final Log LOG = LogFactory.getLog(this.getClass().getName());
  TreeMap<HStoreKey, BytesWritable> memcache 
      = new TreeMap<HStoreKey, BytesWritable>();
@ -42,7 +42,7 @@ public class HMemcache {
  TreeMap<HStoreKey, BytesWritable> snapshot = null;
-  private final HLocking lock = new HLocking();
+  final HLocking lock = new HLocking();
  public HMemcache() {
    super();
@ -147,7 +147,8 @@ public class HMemcache {
   *
   * Operation uses a write lock.
   */
-  public void add(Text row, TreeMap<Text, BytesWritable> columns, long timestamp) {
+  public void add(final Text row, final TreeMap<Text, BytesWritable> columns,
      final long timestamp) {
    this.lock.obtainWriteLock();
    try {
      for (Map.Entry<Text, BytesWritable> es: columns.entrySet()) {
@ -239,7 +240,6 @@ public class HMemcache {
    Vector<BytesWritable> result = new Vector<BytesWritable>();
    HStoreKey curKey = new HStoreKey(key.getRow(), key.getColumn(), key.getTimestamp());
    SortedMap<HStoreKey, BytesWritable> tailMap = map.tailMap(curKey);
    for (Map.Entry<HStoreKey, BytesWritable> es: tailMap.entrySet()) {
      HStoreKey itKey = es.getKey();
      if (itKey.matchesRowCol(curKey)) {
@ -257,9 +257,9 @@ public class HMemcache {
  /**
   * Return a scanner over the keys in the HMemcache
   */
-  public HInternalScannerInterface getScanner(long timestamp, Text targetCols[], Text firstRow)
+  public HInternalScannerInterface getScanner(long timestamp,
      Text targetCols[], Text firstRow)
  throws IOException {  
    return new HMemcacheScanner(timestamp, targetCols, firstRow);
  }
@ -295,16 +295,11 @@ public class HMemcache {
        this.vals = new BytesWritable[backingMaps.length];
        // Generate list of iterators
        HStoreKey firstKey = new HStoreKey(firstRow);
        for(int i = 0; i < backingMaps.length; i++) {
-          if(firstRow.getLength() != 0) {
+          keyIterators[i] = (firstRow.getLength() != 0)?
-            keyIterators[i] = backingMaps[i].tailMap(firstKey).keySet().iterator();
+            backingMaps[i].tailMap(firstKey).keySet().iterator():
-            
+            backingMaps[i].keySet().iterator();
          } else {
            keyIterators[i] = backingMaps[i].keySet().iterator();
          }
          while(getNext(i)) {
            if(! findFirstRow(i, firstRow)) {
              continue;
@ -314,7 +309,6 @@ public class HMemcache {
            }
          }
        }
      } catch(IOException ex) {
        LOG.error(ex);
        close();
@ -326,9 +320,9 @@ public class HMemcache {
     * The user didn't want to start scanning at the first row. This method
     * seeks to the requested row.
     *
-     * @param i         - which iterator to advance
+     * @param i which iterator to advance
-     * @param firstRow  - seek to this row
+     * @param firstRow seek to this row
-     * @return          - true if this is the first row
+     * @return true if this is the first row
     */
    boolean findFirstRow(int i, Text firstRow) {
      return ((firstRow.getLength() == 0)
@ -338,11 +332,11 @@ public class HMemcache {
    /**
     * Get the next value from the specified iterater.
     * 
-     * @param i - which iterator to fetch next value from
+     * @param i Which iterator to fetch next value from
-     * @return - true if there is more data available
+     * @return true if there is more data available
     */
    boolean getNext(int i) {
-      if(! keyIterators[i].hasNext()) {
+      if (!keyIterators[i].hasNext()) {
        closeSubScanner(i);
        return false;
      }
--- a/src/java/org/apache/hadoop/hbase/HMerge.java
+++ b/src/java/org/apache/hadoop/hbase/HMerge.java
@ -146,7 +146,9 @@ public class HMerge implements HConstants {
        nextSize = nextRegion.largestHStore();
-        if((currentSize + nextSize) <= (DESIRED_MAX_FILE_SIZE / 2)) {
+        long maxFilesize =
          conf.getLong("hbase.hregion.max.filesize", DEFAULT_MAX_FILE_SIZE);
        if((currentSize + nextSize) <= (maxFilesize / 2)) {
          // We merge two adjacent regions if their total size is less than
          // one half of the desired maximum size
--- a/src/java/org/apache/hadoop/hbase/HRegion.java
+++ b/src/java/org/apache/hadoop/hbase/HRegion.java
@ -62,7 +62,7 @@ public class HRegion implements HConstants {
  static int MIN_COMMITS_FOR_COMPACTION = 10;
  static Random rand = new Random();
-  private static final Log LOG = LogFactory.getLog(HRegion.class);
+  static final Log LOG = LogFactory.getLog(HRegion.class);
  /**
   * Deletes all the files for a HRegion
@ -74,6 +74,7 @@ public class HRegion implements HConstants {
   */
  public static void deleteRegion(FileSystem fs, Path baseDirectory,
      Text regionName) throws IOException {
    LOG.debug("Deleting region " + regionName);
    fs.delete(HStoreFile.getHRegionDir(baseDirectory, regionName));
  }
@ -135,13 +136,9 @@ public class HRegion implements HConstants {
    // Flush each of the sources, and merge their files into a single 
    // target for each column family.    
    if(LOG.isDebugEnabled()) {
      LOG.debug("flushing and getting file names for region " + srcA.getRegionName());
    }
    TreeSet<HStoreFile> alreadyMerged = new TreeSet<HStoreFile>();
-    TreeMap<Text, Vector<HStoreFile>> filesToMerge = new TreeMap<Text, Vector<HStoreFile>>();
+    TreeMap<Text, Vector<HStoreFile>> filesToMerge =
      new TreeMap<Text, Vector<HStoreFile>>();
    for(HStoreFile src: srcA.flushcache(true)) {
      Vector<HStoreFile> v = filesToMerge.get(src.getColFamily());
      if(v == null) {
@ -151,10 +148,6 @@ public class HRegion implements HConstants {
      v.add(src);
    }
    if(LOG.isDebugEnabled()) {
      LOG.debug("flushing and getting file names for region " + srcB.getRegionName());
    }
    for(HStoreFile src: srcB.flushcache(true)) {
      Vector<HStoreFile> v = filesToMerge.get(src.getColFamily());
      if(v == null) {
@ -187,6 +180,7 @@ public class HRegion implements HConstants {
    }
    filesToMerge.clear();
    for(HStoreFile src: srcA.close()) {
      if(! alreadyMerged.contains(src)) {
        Vector<HStoreFile> v = filesToMerge.get(src.getColFamily());
@ -330,6 +324,7 @@ public class HRegion implements HConstants {
  int maxUnflushedEntries = 0;
  int compactionThreshold = 0;
  private final HLocking lock = new HLocking();
  private long desiredMaxFileSize;
  //////////////////////////////////////////////////////////////////////////////
  // Constructor
@ -382,7 +377,6 @@ public class HRegion implements HConstants {
    // Load in all the HStores.
    for(Map.Entry<Text, HColumnDescriptor> e :
        this.regionInfo.tableDesc.families().entrySet()) {
      Text colFamily = HStoreKey.extractFamily(e.getKey());
      stores.put(colFamily, new HStore(dir, this.regionInfo.regionName,
          e.getValue(), fs, oldLogFile, conf));
@ -404,7 +398,12 @@ public class HRegion implements HConstants {
    // By default, we compact the region if an HStore has more than 10 map files
-    this.compactionThreshold = conf.getInt("hbase.hregion.compactionThreshold", 10);
+    this.compactionThreshold =
      conf.getInt("hbase.hregion.compactionThreshold", 10);
    // By default we split region if a file > DEFAULT_MAX_FILE_SIZE.
    this.desiredMaxFileSize =
      conf.getLong("hbase.hregion.max.filesize", DEFAULT_MAX_FILE_SIZE);
    // HRegion is ready to go!
    this.writestate.writesOngoing = false;
@ -448,6 +447,7 @@ public class HRegion implements HConstants {
          try {
            writestate.wait();
          } catch (InterruptedException iex) {
            // continue
          }
        }
        writestate.writesOngoing = true;
@ -456,25 +456,22 @@ public class HRegion implements HConstants {
      if(! shouldClose) {
        return null;
-
+      }
      } else {
      LOG.info("closing region " + this.regionInfo.regionName);
      Vector<HStoreFile> allHStoreFiles = internalFlushcache();
-        for(Iterator<HStore> it = stores.values().iterator(); it.hasNext(); ) {
+      for (HStore store: stores.values()) {
          HStore store = it.next();
        store.close();
      }
      try {
        return allHStoreFiles;
      } finally {
-          synchronized(writestate) {
+        synchronized (writestate) {
          writestate.closed = true;
          writestate.writesOngoing = false;
        }
        LOG.info("region " + this.regionInfo.regionName + " closed");
      }
      }
    } finally {
      lock.releaseWriteLock();
    }
@ -493,10 +490,11 @@ public class HRegion implements HConstants {
        && (regionInfo.startKey.compareTo(midKey) > 0))
        || ((regionInfo.endKey.getLength() != 0)
            && (regionInfo.endKey.compareTo(midKey) < 0))) {
-      throw new IOException("Region splitkey must lie within region boundaries.");
+      throw new IOException("Region splitkey must lie within region " +
        "boundaries.");
    }
-    LOG.info("splitting region " + this.regionInfo.regionName);
+    LOG.info("Splitting region " + this.regionInfo.regionName);
    Path splits = new Path(regiondir, SPLITDIR);
    if(! fs.exists(splits)) {
@ -524,39 +522,41 @@ public class HRegion implements HConstants {
    // Flush this HRegion out to storage, and turn off flushes
    // or compactions until close() is called.
    // TODO: flushcache can come back null if it can't do the flush. FIX.
    Vector<HStoreFile> hstoreFilesToSplit = flushcache(true);
-    for(Iterator<HStoreFile> it = hstoreFilesToSplit.iterator(); it.hasNext(); ) {
+    for(HStoreFile hsf: hstoreFilesToSplit) {
-      HStoreFile hsf = it.next();
+      if (LOG.isDebugEnabled()) {
-      
+        LOG.debug("Splitting HStore " + hsf.getRegionName() + "/" +
-      if(LOG.isDebugEnabled()) {
+          hsf.getColFamily() + "/" + hsf.fileId());
        LOG.debug("splitting HStore " + hsf.getRegionName() + "/"
            + hsf.getColFamily() + "/" + hsf.fileId());
      }
      HStoreFile dstA = new HStoreFile(conf, splits, regionAInfo.regionName, 
        hsf.getColFamily(), Math.abs(rand.nextLong()));
      HStoreFile dstB = new HStoreFile(conf, splits, regionBInfo.regionName, 
        hsf.getColFamily(), Math.abs(rand.nextLong()));
      hsf.splitStoreFile(midKey, dstA, dstB, fs, conf);
      alreadySplit.add(hsf);
    }
    // We just copied most of the data.
    // Notify the caller that we are about to close the region
    listener.closing(this.getRegionName());
-    listener.regionIsUnavailable(this.getRegionName());
+    // Wait on the last row updates to come in.
-    
+    waitOnRowLocks();
    // Now close the HRegion and copy the small remainder
    // Now close the HRegion
    hstoreFilesToSplit = close();
    for(Iterator<HStoreFile> it = hstoreFilesToSplit.iterator(); it.hasNext(); ) {
      HStoreFile hsf = it.next();
    // Tell listener that region is now closed and that they can therefore
    // clean up any outstanding references.
    listener.closed(this.getRegionName());
    // Copy the small remainder
    for(HStoreFile hsf: hstoreFilesToSplit) {
      if(! alreadySplit.contains(hsf)) {
        if(LOG.isDebugEnabled()) {
-          LOG.debug("splitting HStore " + hsf.getRegionName() + "/"
+          LOG.debug("Splitting HStore " + hsf.getRegionName() + "/"
              + hsf.getColFamily() + "/" + hsf.fileId());
        }
@ -585,8 +585,9 @@ public class HRegion implements HConstants {
    regions[0] = regionA;
    regions[1] = regionB;
-    LOG.info("region split complete. new regions are: " + regions[0].getRegionName()
+    LOG.info("Region split of " + this.regionInfo.regionName + " complete. " +
-        + ", " + regions[1].getRegionName());
+      "New regions are: " + regions[0].getRegionName() + ", " +
      regions[1].getRegionName());
    return regions;
  }
@ -653,22 +654,19 @@ public class HRegion implements HConstants {
   */
  public boolean needsSplit(Text midKey) {
    lock.obtainReadLock();
    try {
      Text key = new Text();
      long maxSize = 0;
-
+      for(HStore store: stores.values()) {
-      for(Iterator<HStore> i = stores.values().iterator(); i.hasNext(); ) {
+        long size = store.getLargestFileSize(key);
        long size = i.next().getLargestFileSize(key);
        if(size > maxSize) {                      // Largest so far
          maxSize = size;
          midKey.set(key);
        }
      }
-      return (maxSize > (DESIRED_MAX_FILE_SIZE + (DESIRED_MAX_FILE_SIZE / 2)));
+      return (maxSize >
-      
+        (this.desiredMaxFileSize + (this.desiredMaxFileSize / 2)));
    } finally {
      lock.releaseReadLock();
    }
@ -701,16 +699,16 @@ public class HRegion implements HConstants {
   */
  public boolean needsCompaction() {
    boolean needsCompaction = false;
-    lock.obtainReadLock();
+    this.lock.obtainReadLock();
    try {
-      for(Iterator<HStore> i = stores.values().iterator(); i.hasNext(); ) {
+      for(HStore store: stores.values()) {
-        if(i.next().getNMaps() > compactionThreshold) {
+        if(store.getNMaps() > this.compactionThreshold) {
          needsCompaction = true;
          break;
        }
      }
    } finally {
-      lock.releaseReadLock();
+      this.lock.releaseReadLock();
    }
    return needsCompaction;
  }
@ -732,41 +730,35 @@ public class HRegion implements HConstants {
    boolean shouldCompact = false;
    lock.obtainReadLock();
    try {
-      synchronized(writestate) {
+      synchronized (writestate) {
-        if((! writestate.writesOngoing)
+        if ((!writestate.writesOngoing) &&
-            && writestate.writesEnabled
+            writestate.writesEnabled &&
-            && (! writestate.closed)
+            (!writestate.closed) &&
-            && recentCommits > MIN_COMMITS_FOR_COMPACTION) {
+            recentCommits > MIN_COMMITS_FOR_COMPACTION) {
          writestate.writesOngoing = true;
          shouldCompact = true;
        }
      }
    } finally {
      lock.releaseReadLock();
    }
-    if(! shouldCompact) {
+      if (!shouldCompact) {
-      LOG.info("not compacting region " + this.regionInfo.regionName);
+        LOG.info("not compacting region " + this.regionInfo);
        return false;
      }
-    lock.obtainWriteLock();
+
-    try {
+      LOG.info("starting compaction on region " + this.regionInfo);
-      LOG.info("starting compaction on region " + this.regionInfo.regionName);
+      for (HStore store : stores.values()) {
      for (Iterator<HStore> it = stores.values().iterator(); it.hasNext();) {
        HStore store = it.next();
        store.compact();
      }
-      LOG.info("compaction completed on region " + this.regionInfo.regionName);
+      LOG.info("compaction completed on region " + this.regionInfo);
      return true;
    } finally {
      lock.releaseReadLock();
      synchronized (writestate) {
        writestate.writesOngoing = false;
        recentCommits = 0;
        writestate.notifyAll();
      }
      lock.releaseWriteLock();
    }
  }
@ -800,7 +792,8 @@ public class HRegion implements HConstants {
   * This method may block for some time, so it should not be called from a 
   * time-sensitive thread.
   */
-  public Vector<HStoreFile> flushcache(boolean disableFutureWrites) throws IOException {
+  public Vector<HStoreFile> flushcache(boolean disableFutureWrites)
  throws IOException {
    boolean shouldFlush = false;
    synchronized(writestate) {
      if((! writestate.writesOngoing)
@ -818,22 +811,22 @@ public class HRegion implements HConstants {
    if(! shouldFlush) {
      if(LOG.isDebugEnabled()) {
-        LOG.debug("not flushing cache for region " + this.regionInfo.regionName);
+        LOG.debug("not flushing cache for region " +
          this.regionInfo.regionName);
      }
      return null;  
    }
    } else {
    try {
      return internalFlushcache();
    } finally {
-        synchronized(writestate) {
+      synchronized (writestate) {
        writestate.writesOngoing = false;
        writestate.notifyAll();
      }
    }
  }
  }
  /**
   * Flushing the cache is a little tricky. We have a lot of updates in the
@ -884,8 +877,7 @@ public class HRegion implements HConstants {
    HMemcache.Snapshot retval = memcache.snapshotMemcacheForLog(log);
    TreeMap<HStoreKey, BytesWritable> memcacheSnapshot = retval.memcacheSnapshot;
    if(memcacheSnapshot == null) {
-      for(Iterator<HStore> it = stores.values().iterator(); it.hasNext(); ) {
+      for(HStore hstore: stores.values()) {
        HStore hstore = it.next();
        Vector<HStoreFile> hstoreFiles = hstore.getAllMapFiles();
        allHStoreFiles.addAll(0, hstoreFiles);
      }
@ -944,12 +936,7 @@ public class HRegion implements HConstants {
  /** Fetch a single data item. */
  public BytesWritable get(Text row, Text column) throws IOException {
    BytesWritable[] results = get(row, column, Long.MAX_VALUE, 1);
-    if(results == null) {
+    return (results == null)? null: results[0];
      return null;
    } else {
      return results[0];
    }
  }
  /** Fetch multiple versions of a single data item */
@ -972,13 +959,13 @@ public class HRegion implements HConstants {
    // Obtain the row-lock
-    obtainLock(row);
+    obtainRowLock(row);
    try {
      // Obtain the -col results
      return get(new HStoreKey(row, column, timestamp), numVersions);
    } finally {
-      releaseLock(row);
+      releaseRowLock(row);
    }
  }
@ -1042,7 +1029,8 @@ public class HRegion implements HConstants {
   * Return an iterator that scans over the HRegion, returning the indicated 
   * columns.  This Iterator must be closed by the caller.
   */
-  public HInternalScannerInterface getScanner(Text[] cols, Text firstRow) throws IOException {
+  public HInternalScannerInterface getScanner(Text[] cols, Text firstRow)
  throws IOException {
    lock.obtainReadLock();
    try {
      TreeSet<Text> families = new TreeSet<Text>();
@ -1052,12 +1040,10 @@ public class HRegion implements HConstants {
      HStore[] storelist = new HStore[families.size()];
      int i = 0;
-      for(Iterator<Text> it = families.iterator(); it.hasNext(); ) {
+      for (Text family: families) {
        Text family = it.next();
        storelist[i++] = stores.get(family);
      }
      return new HScanner(cols, firstRow, memcache, storelist);
    } finally {
      lock.releaseReadLock();
    }
@ -1068,26 +1054,26 @@ public class HRegion implements HConstants {
  //////////////////////////////////////////////////////////////////////////////
  /**
-   * The caller wants to apply a series of writes to a single row in the HRegion.
+   * The caller wants to apply a series of writes to a single row in the
-   * The caller will invoke startUpdate(), followed by a series of calls to 
+   * HRegion. The caller will invoke startUpdate(), followed by a series of
-   * put/delete, then finally either abort() or commit().
+   * calls to put/delete, then finally either abort() or commit().
   *
-   * Note that we rely on the external caller to properly abort() or commit() 
+   * <p>Note that we rely on the external caller to properly abort() or
-   * every transaction.  If the caller is a network client, there should be a 
+   * commit() every transaction.  If the caller is a network client, there
-   * lease-system in place that automatically aborts() transactions after a 
+   * should be a lease-system in place that automatically aborts() transactions
-   * specified quiet period.
+   * after a specified quiet period.
   * 
   * @param row Row to update
   * @return lockid
   * @see #put(long, Text, BytesWritable)
   */
  public long startUpdate(Text row) throws IOException {
-
+    // We obtain a per-row lock, so other clients will block while one client
-    // We obtain a per-row lock, so other clients will
+    // performs an update.  The read lock is released by the client calling
-    // block while one client performs an update.
+    // #commit or #abort or if the HRegionServer lease on the lock expires.
-
+    // See HRegionServer#RegionListener for how the expire on HRegionServer
-    lock.obtainReadLock();
+    // invokes a HRegion#abort.
-    try {
+    return obtainRowLock(row);
      return obtainLock(row);
    } finally {
      lock.releaseReadLock();
    }
  }
  /**
@ -1099,7 +1085,8 @@ public class HRegion implements HConstants {
   * This method really just tests the input, then calls an internal localput() 
   * method.
   */
-  public void put(long lockid, Text targetCol, BytesWritable val) throws IOException {
+  public void put(long lockid, Text targetCol, BytesWritable val)
  throws IOException {
    if(val.getSize() == DELETE_BYTES.getSize()
        && val.compareTo(DELETE_BYTES) == 0) {
      throw new IOException("Cannot insert value: " + val);
@ -1114,14 +1101,21 @@ public class HRegion implements HConstants {
    localput(lockid, targetCol, DELETE_BYTES);
  }
-  /**
+  /*
   * Private implementation.
   * 
-   * localput() is used for both puts and deletes. We just place the values into
+   * localput() is used for both puts and deletes. We just place the values
-   * a per-row pending area, until a commit() or abort() call is received.
+   * into a per-row pending area, until a commit() or abort() call is received.
   * (Or until the user's write-lock expires.)
   * 
   * @param lockid
   * @param targetCol
   * @param val Value to enter into cell
   * @throws IOException
   */
-  void localput(long lockid, Text targetCol, BytesWritable val) throws IOException {
+  void localput(final long lockid, final Text targetCol,
    final BytesWritable val)
  throws IOException {
    checkColumn(targetCol);
    Text row = getRowFromLock(lockid);
@ -1132,15 +1126,12 @@ public class HRegion implements HConstants {
    // This sync block makes localput() thread-safe when multiple
    // threads from the same client attempt an insert on the same 
    // locked row (via lockid).
    synchronized(row) {
      // This check makes sure that another thread from the client
      // hasn't aborted/committed the write-operation.
      if(row != getRowFromLock(lockid)) {
-        throw new LockException("Locking error: put operation on lock " + lockid 
+        throw new LockException("Locking error: put operation on lock " +
-            + " unexpected aborted by another thread");
+            lockid + " unexpected aborted by another thread");
      }
      TreeMap<Text, BytesWritable> targets = targetColumns.get(lockid);
@ -1178,22 +1169,22 @@ public class HRegion implements HConstants {
      }
      targetColumns.remove(lockid);
-      releaseLock(row);
+      releaseRowLock(row);
    }
  }
  /**
-   * Commit a pending set of writes to the memcache. This also results in writing
+   * Commit a pending set of writes to the memcache. This also results in
-   * to the change log.
+   * writing to the change log.
   *
   * Once updates hit the change log, they are safe.  They will either be moved 
   * into an HStore in the future, or they will be recovered from the log.
   * @param lockid Lock for row we're to commit.
   * @throws IOException
   */
-  public void commit(long lockid) throws IOException {
+  public void commit(final long lockid) throws IOException {
    // Remove the row from the pendingWrites list so 
    // that repeated executions won't screw this up.
    Text row = getRowFromLock(lockid);
    if(row == null) {
      throw new LockException("No write lock for lockid " + lockid);
@ -1201,22 +1192,16 @@ public class HRegion implements HConstants {
    // This check makes sure that another thread from the client
    // hasn't aborted/committed the write-operation
    synchronized(row) {
      // We can now commit the changes.
      // Add updates to the log and add values to the memcache.
      long commitTimestamp = System.currentTimeMillis();
      log.append(regionInfo.regionName, regionInfo.tableDesc.getName(), row, 
-          targetColumns.get(lockid), commitTimestamp);
+        targetColumns.get(Long.valueOf(lockid)), commitTimestamp);
-      
+      memcache.add(row, targetColumns.get(Long.valueOf(lockid)),
-      memcache.add(row, targetColumns.get(lockid), commitTimestamp);
+        commitTimestamp);
      // OK, all done!
-
+      targetColumns.remove(Long.valueOf(lockid));
-      targetColumns.remove(lockid);
+      releaseRowLock(row);
      releaseLock(row);
    }
    recentCommits++;
    this.commitsSinceFlush++;
@ -1235,9 +1220,10 @@ public class HRegion implements HConstants {
      // all's well
    } else {
-      throw new IOException("Requested row out of range for HRegion "
+      throw new WrongRegionException("Requested row out of range for " +
-          + regionInfo.regionName + ", startKey='" + regionInfo.startKey
+        "HRegion " + regionInfo.regionName + ", startKey='" +
-          + "', endKey='" + regionInfo.endKey + "', row='" + row + "'");
+        regionInfo.startKey + "', endKey='" + regionInfo.endKey + "', row='" +
        row + "'");
    }
  }
@ -1255,25 +1241,32 @@ public class HRegion implements HConstants {
   * Obtain a lock on the given row.  Blocks until success.
   *
   * I know it's strange to have two mappings:
   * <pre>
   *   ROWS  ==> LOCKS
   * </pre>
   * as well as
   * <pre>
   *   LOCKS ==> ROWS
   * </pre>
   *
-   * But it acts as a guard on the client; a miswritten client just can't submit
+   * But it acts as a guard on the client; a miswritten client just can't
-   * the name of a row and start writing to it; it must know the correct lockid,
+   * submit the name of a row and start writing to it; it must know the correct
-   * which matches the lock list in memory.
+   * lockid, which matches the lock list in memory.
   * 
-   * It would be more memory-efficient to assume a correctly-written client, 
+   * <p>It would be more memory-efficient to assume a correctly-written client, 
   * which maybe we'll do in the future.
   * 
   * @param row Name of row to lock.
   * @return The id of the held lock.
   */
-  long obtainLock(Text row) throws IOException {
+  long obtainRowLock(Text row) throws IOException {
    checkRow(row);
    synchronized(rowsToLocks) {
      while(rowsToLocks.get(row) != null) {
        try {
          rowsToLocks.wait();
        } catch (InterruptedException ie) {
          // Empty
        }
      }
@ -1285,7 +1278,7 @@ public class HRegion implements HConstants {
    }
  }
-  Text getRowFromLock(long lockid) throws IOException {
+  Text getRowFromLock(long lockid) {
    // Pattern is that all access to rowsToLocks and/or to
    // locksToRows is via a lock on rowsToLocks.
    synchronized(rowsToLocks) {
@ -1293,17 +1286,32 @@ public class HRegion implements HConstants {
    }
  }
-  /** Release the row lock! */
+  /** Release the row lock!
-  void releaseLock(Text row) throws IOException {
+   * @param lock Name of row whose lock we are to release
   */
  void releaseRowLock(Text row) {
    synchronized(rowsToLocks) {
      long lockid = rowsToLocks.remove(row).longValue();
      locksToRows.remove(lockid);
      rowsToLocks.notifyAll();
    }
  }
-  /*******************************************************************************
+  
  private void waitOnRowLocks() {
    synchronized (this.rowsToLocks) {
      while (this.rowsToLocks.size() > 0) {
        try {
          this.rowsToLocks.wait();
        } catch (InterruptedException e) {
          // Catch. Let while test determine loop-end.
        }
      }
    }
  }
  /*
   * HScanner is an iterator through a bunch of rows in an HRegion.
-   ******************************************************************************/
+   */
  private static class HScanner implements HInternalScannerInterface {
    private HInternalScannerInterface[] scanners;
    private TreeMap<Text, BytesWritable>[] resultSets;
@ -1315,9 +1323,7 @@ public class HRegion implements HConstants {
    @SuppressWarnings("unchecked")
    public HScanner(Text[] cols, Text firstRow, HMemcache memcache, HStore[] stores)
    throws IOException {  
      long scanTime = System.currentTimeMillis();
      this.scanners = new HInternalScannerInterface[stores.length + 1];
      for(int i = 0; i < this.scanners.length; i++) {
        this.scanners[i] = null;
@ -1332,12 +1338,9 @@ public class HRegion implements HConstants {
      // All results will match the required column-set and scanTime.
      // NOTE: the memcache scanner should be the first scanner
      try {
        HInternalScannerInterface scanner =
          memcache.getScanner(scanTime, cols, firstRow);
        if(scanner.isWildcardScanner()) {
          this.wildcardMatch = true;
        }
@ -1368,8 +1371,7 @@ public class HRegion implements HConstants {
      for(int i = 0; i < scanners.length; i++) {
        keys[i] = new HStoreKey();
        resultSets[i] = new TreeMap<Text, BytesWritable>();
-
+        if(scanners[i] != null && !scanners[i].next(keys[i], resultSets[i])) {
        if(scanners[i] != null && ! scanners[i].next(keys[i], resultSets[i])) {
          closeScanner(i);
        }
      }
@ -1393,13 +1395,12 @@ public class HRegion implements HConstants {
     * Grab the next row's worth of values.  The HScanner will return the most 
     * recent data value for each row that is not newer than the target time.
     */
-    public boolean next(HStoreKey key, TreeMap<Text, BytesWritable> results) throws IOException {
+    public boolean next(HStoreKey key, TreeMap<Text, BytesWritable> results)
-      
+    throws IOException {
      // Find the lowest-possible key.
      Text chosenRow = null;
      long chosenTimestamp = -1;
-      for(int i = 0; i < keys.length; i++) {
+      for(int i = 0; i < this.keys.length; i++) {
        if(scanners[i] != null
            && (chosenRow == null
                || (keys[i].getRow().compareTo(chosenRow) < 0)
@ -1412,7 +1413,6 @@ public class HRegion implements HConstants {
      }
      // Store the key and results for each sub-scanner. Merge them as appropriate.
      boolean insertedItem = false;
      if(chosenTimestamp > 0) {
        key.setRow(chosenRow);
@ -1422,8 +1422,6 @@ public class HRegion implements HConstants {
        for(int i = 0; i < scanners.length; i++) {
          while((scanners[i] != null)
              && (keys[i].getRow().compareTo(chosenRow) == 0)) {
            // If we are doing a wild card match or there are multiple matchers
            // per column, we need to scan all the older versions of this row
            // to pick up the rest of the family members
@ -1439,11 +1437,7 @@ public class HRegion implements HConstants {
            //       values with older ones. So now we only insert
            //       a result if the map does not contain the key.
-            for(Iterator<Map.Entry<Text, BytesWritable>> it
+            for(Map.Entry<Text, BytesWritable> e: resultSets[i].entrySet()) {
                = resultSets[i].entrySet().iterator();
                it.hasNext(); ) {
              Map.Entry<Text, BytesWritable> e = it.next();
              if(!results.containsKey(e.getKey())) {
                results.put(e.getKey(), e.getValue());
                insertedItem = true;
@ -1476,7 +1470,6 @@ public class HRegion implements HConstants {
    void closeScanner(int i) {
      try {
        scanners[i].close();
      } finally {
        scanners[i] = null;
        keys[i] = null;
@ -1493,4 +1486,160 @@ public class HRegion implements HConstants {
      }
    }
  }
  // Utility methods
  /**
   * Convenience method creating new HRegions.
   * @param regionId ID to use
   * @param tableDesc Descriptor
   * @param dir Home directory for the new region.
   * @param conf
   * @return New META region (ROOT or META).
   * @throws IOException
   */
  public static HRegion createHRegion(final long regionId,
    final HTableDescriptor tableDesc, final Path dir, final Configuration conf)
  throws IOException {
    return createHRegion(new HRegionInfo(regionId, tableDesc, null, null),
      dir, conf, null, null);
  }
  /**
   * Convenience method creating new HRegions. Used by createTable and by the
   * bootstrap code in the HMaster constructor
   * 
   * @param info Info for region to create.
   * @param dir Home dir for new region
   * @param conf
   * @param initialFiles InitialFiles to pass new HRegion. Pass null if none.
   * @param oldLogFile Old log file to use in region initialization.  Pass null
   * if none. 
   * @return new HRegion
   * 
   * @throws IOException
   */
  public static HRegion createHRegion(final HRegionInfo info,
    final Path dir, final Configuration conf, final Path initialFiles,
    final Path oldLogFile) 
  throws IOException {
    Path regionDir = HStoreFile.getHRegionDir(dir, info.regionName);
    FileSystem fs = FileSystem.get(conf);
    fs.mkdirs(regionDir);
    return new HRegion(dir,
      new HLog(fs, new Path(regionDir, HREGION_LOGDIR_NAME), conf),
      fs, conf, info, initialFiles, oldLogFile);
  }
  /**
   * Inserts a new region's meta information into the passed
   * <code>meta</code> region. Used by the HMaster bootstrap code adding
   * new table to ROOT table.
   * 
   * @param meta META HRegion to be updated
   * @param r HRegion to add to <code>meta</code>
   *
   * @throws IOException
   */
  public static void addRegionToMETA(HRegion meta, HRegion r)
  throws IOException {  
    // The row key is the region name
    long writeid = meta.startUpdate(r.getRegionName());
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    DataOutputStream s = new DataOutputStream(bytes);
    r.getRegionInfo().write(s);
    meta.put(writeid, COL_REGIONINFO, new BytesWritable(bytes.toByteArray()));
    meta.commit(writeid);
  }
  public static void addRegionToMETA(final HClient client,
      final Text table, final HRegion region,
      final HServerAddress serverAddress,
      final long startCode)
  throws IOException {
    client.openTable(table);
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    DataOutputStream out = new DataOutputStream(bytes);
    region.getRegionInfo().write(out);
    long lockid = client.startUpdate(region.getRegionName());
    client.put(lockid, COL_REGIONINFO, bytes.toByteArray());
    client.put(lockid, COL_SERVER,
      serverAddress.toString().getBytes(UTF8_ENCODING));
    client.put(lockid, COL_STARTCODE,
      String.valueOf(startCode).getBytes(UTF8_ENCODING));
    client.commit(lockid);
    LOG.info("Added region " + region.getRegionName() + " to table " + table);
  }
  /**
   * Delete <code>region</code> from META <code>table</code>.
   * @param client Client to use running update.
   * @param table META table we are to delete region from.
   * @param regionName Region to remove.
   * @throws IOException
   */
  public static void removeRegionFromMETA(final HClient client,
      final Text table, final Text regionName)
  throws IOException {
    client.openTable(table);
    long lockid = client.startUpdate(regionName);
    client.delete(lockid, COL_REGIONINFO);
    client.delete(lockid, COL_SERVER);
    client.delete(lockid, COL_STARTCODE);
    client.commit(lockid);
    LOG.info("Removed " + regionName + " from table " + table);
  }
  /**
   * @param data Map of META row labelled column data.
   * @return Server
   */
  static HRegionInfo getRegionInfo(final TreeMap<Text, byte[]> data)
  throws IOException {
    byte[] bytes = data.get(COL_REGIONINFO);
    if (bytes == null || bytes.length == 0) {
      throw new IOException("no value for " + COL_REGIONINFO);
    }
    DataInputBuffer in = new DataInputBuffer();
    in.reset(bytes, bytes.length);
    HRegionInfo info = new HRegionInfo();
    info.readFields(in);
    return info;
  }
  /**
   * @param data Map of META row labelled column data.
   * @return Server
   */
  static String getServerName(final TreeMap<Text, byte[]> data) {
    byte [] bytes = data.get(COL_SERVER);
    String name = null;
    try {
      name = (bytes != null && bytes.length != 0) ?
          new String(bytes, UTF8_ENCODING): null;
    } catch(UnsupportedEncodingException e) {
      assert(false);
    }
    return (name != null)? name.trim(): name;
  }
  /**
   * @param data Map of META row labelled column data.
   * @return Start code.
   */
  static long getStartCode(final TreeMap<Text, byte[]> data) {
    long startCode = -1L;
    byte [] bytes = data.get(COL_STARTCODE);
    if(bytes != null && bytes.length != 0) {
      try {
        startCode = Long.parseLong(new String(bytes, UTF8_ENCODING).trim());
      } catch(NumberFormatException e) {
        LOG.error("Failed getting " + COL_STARTCODE, e);
      } catch(UnsupportedEncodingException e) {
        LOG.error("Failed getting " + COL_STARTCODE, e);
      }
    }
    return startCode;
  }
 }
--- a/src/java/org/apache/hadoop/hbase/HRegionInfo.java
+++ b/src/java/org/apache/hadoop/hbase/HRegionInfo.java
@ -20,9 +20,11 @@ import java.io.DataInput;
 import java.io.DataInputStream;
 import java.io.DataOutput;
 import java.io.IOException;
 import java.util.Map;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.io.WritableComparable;
 import org.apache.hadoop.io.WritableComparable;
 /**
 * HRegion information.
@ -130,7 +132,21 @@ public class HRegionInfo implements WritableComparable {
  //////////////////////////////////////////////////////////////////////////////
  public int compareTo(Object o) {
-    HRegionInfo other = (HRegionInfo)o;
+    HRegionInfo other = (HRegionInfo) o;
-    return regionName.compareTo(other.regionName);
+    
    // Are regions of same table?
    int result = this.tableDesc.compareTo(other.tableDesc);
    if (result != 0) {
      return result;
    }
    // Compare start keys.
    result = this.startKey.compareTo(other.startKey);
    if (result != 0) {
      return result;
    }
    // Compare end keys.
    return this.endKey.compareTo(other.endKey);
  }
 }
--- a/src/java/org/apache/hadoop/hbase/HRegionServer.java
+++ b/src/java/org/apache/hadoop/hbase/HRegionServer.java
@ -15,17 +15,28 @@
 */
 package org.apache.hadoop.hbase;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Random;
 import java.util.TreeMap;
 import java.util.Vector;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.apache.hadoop.io.*;
+import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.fs.*;
+import org.apache.hadoop.fs.FileSystem;
-import org.apache.hadoop.ipc.*;
+import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.io.BytesWritable;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.io.retry.RetryProxy;
 import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.ipc.Server;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.conf.*;
 import java.io.*;
 import java.util.*;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 /*******************************************************************************
 * HRegionServer makes a set of HRegions available to clients.  It checks in with
@ -34,196 +45,194 @@ import java.util.concurrent.locks.ReentrantReadWriteLock;
 public class HRegionServer
    implements HConstants, HRegionInterface, Runnable {
-  public long getProtocolVersion(String protocol, 
+  public long getProtocolVersion(final String protocol, 
-      long clientVersion) throws IOException { 
+      @SuppressWarnings("unused") final long clientVersion)
  throws IOException { 
    if (protocol.equals(HRegionInterface.class.getName())) {
      return HRegionInterface.versionID;
-    } else {
+    }
    throw new IOException("Unknown protocol to name node: " + protocol);
  }
  }
-  private static final Log LOG = LogFactory.getLog(HRegionServer.class);
+  static final Log LOG = LogFactory.getLog(HRegionServer.class);
-  private volatile boolean stopRequested;
+  volatile boolean stopRequested;
  private Path regionDir;
-  private HServerInfo info;
+  HServerInfo info;
-  private Configuration conf;
+  Configuration conf;
  private Random rand;
-  private TreeMap<Text, HRegion> regions;               // region name -> HRegion
+  
-  private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
+  // region name -> HRegion
  TreeMap<Text, HRegion> onlineRegions = new TreeMap<Text, HRegion>();
  Map<Text, HRegion> retiringRegions = new HashMap<Text, HRegion>();
  final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
  private Vector<HMsg> outboundMsgs;
-  private long threadWakeFrequency;
+  long threadWakeFrequency;
  private int maxLogEntries;
  private long msgInterval;
  private int numRetries;
  // Check to see if regions should be split
-  
+  long splitOrCompactCheckFrequency;
  private long splitOrCompactCheckFrequency;
  private SplitOrCompactChecker splitOrCompactChecker;
  private Thread splitOrCompactCheckerThread;
-  private Integer splitOrCompactLock = 0;
+  Integer splitOrCompactLock = Integer.valueOf(0);
-  private class SplitOrCompactChecker implements Runnable, RegionUnavailableListener {
+  /*
-    private HClient client = new HClient(conf);
+   * Interface used by the {@link org.apache.hadoop.io.retry} mechanism.
    /* (non-Javadoc)
     * @see org.apache.hadoop.hbase.RegionUnavailableListener#regionIsUnavailable(org.apache.hadoop.io.Text)
   */
-    public void regionIsUnavailable(Text regionName) {
+  interface UpdateMetaInterface {
    /*
     * @return True if succeeded.
     * @throws IOException
     */
   boolean update() throws IOException;
  }
  class SplitOrCompactChecker implements Runnable, RegionUnavailableListener {
    HClient client = new HClient(conf);
    public void closing(final Text regionName) {
      lock.writeLock().lock();
      try {
-        regions.remove(regionName);
+        // Remove region from regions Map and add it to the Map of retiring
        // regions.
        retiringRegions.put(regionName, onlineRegions.remove(regionName));
        if (LOG.isDebugEnabled()) {
          LOG.debug("Adding " + regionName + " to retiringRegions");
        }
      } finally {
        lock.writeLock().unlock();
      }
    }
    public void closed(final Text regionName) {
      lock.writeLock().lock();
      try {
        retiringRegions.remove(regionName);
        if (LOG.isDebugEnabled()) {
          LOG.debug("Removing " + regionName + " from retiringRegions");
        }
      } finally {
        lock.writeLock().unlock();
      }
    }
    /* (non-Javadoc)
     * @see java.lang.Runnable#run()
     */
    public void run() {
      while(! stopRequested) {
        long startTime = System.currentTimeMillis();
        synchronized(splitOrCompactLock) { // Don't interrupt us while we're working
          // Grab a list of regions to check
          Vector<HRegion> regionsToCheck = new Vector<HRegion>();
          lock.readLock().lock();
          try {
-            regionsToCheck.addAll(regions.values());
+            regionsToCheck.addAll(onlineRegions.values());
          } finally {
            lock.readLock().unlock();
          }
          try {
-            for(Iterator<HRegion>it = regionsToCheck.iterator(); it.hasNext(); ) {
+            for(HRegion cur: regionsToCheck) {
              HRegion cur = it.next();
              if(cur.isClosed()) {
                continue;                               // Skip if closed
              }
              if(cur.needsCompaction()) {
-
+                // Best time to split a region is right after compaction
                // The best time to split a region is right after it has been compacted
                if(cur.compactStores()) {
                  Text midKey = new Text();
                  if(cur.needsSplit(midKey)) {
-                    Text oldRegion = cur.getRegionName();
+                    split(cur, midKey);
                    LOG.info("splitting region: " + oldRegion);
                    HRegion[] newRegions = cur.closeAndSplit(midKey, this);
                    // When a region is split, the META table needs to updated if we're
                    // splitting a 'normal' region, and the ROOT table needs to be
                    // updated if we are splitting a META region.
                    if(LOG.isDebugEnabled()) {
                      LOG.debug("region split complete. updating meta");
                    }
                    Text tableToUpdate =
                      (oldRegion.find(META_TABLE_NAME.toString()) == 0) ?
                          ROOT_TABLE_NAME : META_TABLE_NAME;
                    for(int tries = 0; tries < numRetries; tries++) {
                      try {
                        client.openTable(tableToUpdate);
                        long lockid = client.startUpdate(oldRegion);
                        client.delete(lockid, COL_REGIONINFO);
                        client.delete(lockid, COL_SERVER);
                        client.delete(lockid, COL_STARTCODE);
                        client.commit(lockid);
                        for(int i = 0; i < newRegions.length; i++) {
                          ByteArrayOutputStream bytes = new ByteArrayOutputStream();
                          DataOutputStream out = new DataOutputStream(bytes);
                          newRegions[i].getRegionInfo().write(out);
                          lockid = client.startUpdate(newRegions[i].getRegionName());
                          client.put(lockid, COL_REGIONINFO, bytes.toByteArray());
                          client.put(lockid, COL_SERVER, 
                              info.getServerAddress().toString().getBytes(UTF8_ENCODING));
                          client.put(lockid, COL_STARTCODE, 
                              String.valueOf(info.getStartCode()).getBytes(UTF8_ENCODING));
                          client.commit(lockid);
                        }
                        // Now tell the master about the new regions
                        if(LOG.isDebugEnabled()) {
                          LOG.debug("reporting region split to master");
                        }
                        reportSplit(newRegions[0].getRegionInfo(), newRegions[1].getRegionInfo());
                        LOG.info("region split successful. old region=" + oldRegion
                            + ", new regions: " + newRegions[0].getRegionName() + ", "
                            + newRegions[1].getRegionName());
                        // Finally, start serving the new regions
                        lock.writeLock().lock();
                        try {
                          regions.put(newRegions[0].getRegionName(), newRegions[0]);
                          regions.put(newRegions[1].getRegionName(), newRegions[1]);
                        } finally {
                          lock.writeLock().unlock();
                        }
                      } catch(NotServingRegionException e) {
                        if(tries == numRetries - 1) {
                          throw e;
                        }
                        continue;
                      }
                      break;
                    }
                  }
                }
              }
            }
          } catch(IOException e) {
            //TODO: What happens if this fails? Are we toast?
-            LOG.error(e);
+            LOG.error("What happens if this fails? Are we toast?", e);
          }
        }
        if (stopRequested) {
          continue;
        }
        // Sleep
-        long waitTime = stopRequested ? 0
+        long waitTime = splitOrCompactCheckFrequency -
-            : splitOrCompactCheckFrequency - (System.currentTimeMillis() - startTime);
+          (System.currentTimeMillis() - startTime);
        if (waitTime > 0) {
          try {
            if (LOG.isDebugEnabled()) {
              LOG.debug("Sleep splitOrCompactChecker");
            }
            Thread.sleep(waitTime);
            if (LOG.isDebugEnabled()) {
              LOG.debug("Wake splitOrCompactChecker");
            }
          } catch(InterruptedException iex) {
            // continue
          }
        }
      }
      LOG.info("splitOrCompactChecker exiting");
    }
    private void split(final HRegion region, final Text midKey)
    throws IOException {
      final Text oldRegion = region.getRegionName();
      final HRegion[] newRegions = region.closeAndSplit(midKey, this);
      // When a region is split, the META table needs to updated if we're
      // splitting a 'normal' region, and the ROOT table needs to be
      // updated if we are splitting a META region.
      final Text tableToUpdate =
        (oldRegion.find(META_TABLE_NAME.toString()) == 0) ?
            ROOT_TABLE_NAME : META_TABLE_NAME;
      if(LOG.isDebugEnabled()) {
-        LOG.debug("splitOrCompactChecker exiting");
+        LOG.debug("Updating " + tableToUpdate + " with region split info");
      }
      // Wrap the update of META region with an org.apache.hadoop.io.retry.
      UpdateMetaInterface implementation = new UpdateMetaInterface() {
        public boolean update() throws IOException {
          HRegion.removeRegionFromMETA(client, tableToUpdate,
            region.getRegionName());
          for (int i = 0; i < newRegions.length; i++) {
            HRegion.addRegionToMETA(client, tableToUpdate, newRegions[i],
              info.getServerAddress(), info.getStartCode());
          }
          // Now tell the master about the new regions
          if (LOG.isDebugEnabled()) {
            LOG.debug("Reporting region split to master");
          }
          reportSplit(newRegions[0].getRegionInfo(), newRegions[1].
            getRegionInfo());
          LOG.info("region split, META update, and report to master all" +
            " successful. Old region=" + oldRegion + ", new regions: " +
            newRegions[0].getRegionName() + ", " +
            newRegions[1].getRegionName());
          // Finally, start serving the new regions
          lock.writeLock().lock();
          try {
            onlineRegions.put(newRegions[0].getRegionName(), newRegions[0]);
            onlineRegions.put(newRegions[1].getRegionName(), newRegions[1]);
          } finally {
            lock.writeLock().unlock();
          }
          return true;
        }
      };
      // Get retry proxy wrapper around 'implementation'.
      UpdateMetaInterface retryProxy = (UpdateMetaInterface)RetryProxy.
        create(UpdateMetaInterface.class, implementation,
        client.getRetryPolicy());
      // Run retry.
      retryProxy.update();
    }
  }
  // Cache flushing  
  private Flusher cacheFlusher;
  private Thread cacheFlusherThread;
-  private Integer cacheFlusherLock = 0;
+  Integer cacheFlusherLock = Integer.valueOf(0);
-  private class Flusher implements Runnable {
+  class Flusher implements Runnable {
    public void run() {
      while(! stopRequested) {
        long startTime = System.currentTimeMillis();
@ -235,23 +244,20 @@ public class HRegionServer
          Vector<HRegion> toFlush = new Vector<HRegion>();
          lock.readLock().lock();
          try {
-            toFlush.addAll(regions.values());
+            toFlush.addAll(onlineRegions.values());
          } finally {
            lock.readLock().unlock();
          }
          // Flush them, if necessary
-          for(Iterator<HRegion> it = toFlush.iterator(); it.hasNext(); ) {
+          for(HRegion cur: toFlush) {
            HRegion cur = it.next();
            if(cur.isClosed()) {                // Skip if closed
              continue;
            }
            try {
              cur.optionallyFlush();
            } catch(IOException iex) {
              LOG.error(iex);
            }
@ -263,21 +269,14 @@ public class HRegionServer
            : threadWakeFrequency - (System.currentTimeMillis() - startTime);
        if(waitTime > 0) {
          if (LOG.isDebugEnabled()) {
            LOG.debug("Sleep cacheFlusher");
          }
          try {
            Thread.sleep(waitTime);
          } catch(InterruptedException iex) {
-          }
+            // continue
          if (LOG.isDebugEnabled()) {
            LOG.debug("Wake cacheFlusher");
          }
        }
      }
-      if(LOG.isDebugEnabled()) {
+      LOG.info("cacheFlusher exiting");
        LOG.debug("cacheFlusher exiting");
      }
    }
  }
@ -287,45 +286,45 @@ public class HRegionServer
  private Path oldlogfile;
  // Logging
-  
+  HLog log;
  private HLog log;
  private LogRoller logRoller;
  private Thread logRollerThread;
-  private Integer logRollerLock = 0;
+  Integer logRollerLock = Integer.valueOf(0);
-  private class LogRoller implements Runnable {
+  
  /**
   * Log rolling Runnable.
   */
  class LogRoller implements Runnable {
    private int maxLogEntries =
      conf.getInt("hbase.regionserver.maxlogentries", 30 * 1000);
    public void run() {
      while(! stopRequested) {
        synchronized(logRollerLock) {
          // If the number of log entries is high enough, roll the log.  This is a
          // very fast operation, but should not be done too frequently.
          int nEntries = log.getNumEntries();
-          if(nEntries > maxLogEntries) {
+          if(nEntries > this.maxLogEntries) {
            try {
              if (LOG.isDebugEnabled()) {
                LOG.debug("Rolling log. Number of entries is: " + nEntries);
              }
              log.rollWriter();
            } catch(IOException iex) {
              // continue
            }
          }
        }
        if(!stopRequested) {
          if (LOG.isDebugEnabled()) {
            LOG.debug("Sleep logRoller");
          }
          try {
            Thread.sleep(threadWakeFrequency);
          } catch(InterruptedException iex) {
-          }
+            // continue
          if (LOG.isDebugEnabled()) {
            LOG.debug("Wake logRoller");
          }
        }
      }
-      if(LOG.isDebugEnabled()) {
+      LOG.info("logRoller exiting");
        LOG.debug("logRoller exiting");
      }
    }
  }
@ -338,7 +337,6 @@ public class HRegionServer
  private Server server;
  // Leases
  private Leases leases;
  /** Start a HRegionServer at the default location */
@ -357,18 +355,17 @@ public class HRegionServer
    this.regionDir = regionDir;
    this.conf = conf;
    this.rand = new Random();
    this.regions = new TreeMap<Text, HRegion>();
    this.outboundMsgs = new Vector<HMsg>();
    this.scanners =
      Collections.synchronizedMap(new TreeMap<Text, HInternalScannerInterface>());
    // Config'ed params
    this.threadWakeFrequency = conf.getLong(THREAD_WAKE_FREQUENCY, 10 * 1000);
    this.maxLogEntries = conf.getInt("hbase.regionserver.maxlogentries", 30 * 1000);
    this.msgInterval = conf.getLong("hbase.regionserver.msginterval",
      15 * 1000);
    this.splitOrCompactCheckFrequency =
-      conf.getLong("hbase.regionserver.thread.splitcompactcheckfrequency", 60 * 1000);
+      conf.getLong("hbase.regionserver.thread.splitcompactcheckfrequency",
      60 * 1000);
    // Cache flushing
    this.cacheFlusher = new Flusher();
@ -448,7 +445,7 @@ public class HRegionServer
   * Set a flag that will cause all the HRegionServer threads to shut down
   * in an orderly fashion.
   */
-  public synchronized void stop() throws IOException {
+  public synchronized void stop() {
    stopRequested = true;
    notifyAll();                        // Wakes run() if it is sleeping
  }
@ -460,24 +457,30 @@ public class HRegionServer
    try {
      this.workerThread.join();
    } catch(InterruptedException iex) {
      // continue
    }
    try {
      this.logRollerThread.join();
    } catch(InterruptedException iex) {
      // continue
    }
    try {
      this.cacheFlusherThread.join();
    } catch(InterruptedException iex) {
      // continue
    }
    try {
      this.splitOrCompactCheckerThread.join();
    } catch(InterruptedException iex) {
      // continue
    }
    try {
      this.server.join();
    } catch(InterruptedException iex) {
      // continue
    }
-    LOG.info("HRegionServer stopped at: " + info.getServerAddress().toString());
+    LOG.info("HRegionServer stopped at: " +
      info.getServerAddress().toString());
  }
  /**
@ -506,9 +509,6 @@ public class HRegionServer
            : msgInterval - (System.currentTimeMillis() - lastMsg);
        if(waitTime > 0) {
          if (LOG.isDebugEnabled()) {
            LOG.debug("Sleep");
          }
          synchronized (this) {
            try {
              wait(waitTime);
@ -586,9 +586,6 @@ public class HRegionServer
        waitTime = stopRequested ? 0
            : msgInterval - (System.currentTimeMillis() - lastMsg);
        if (waitTime > 0) {
          if (LOG.isDebugEnabled()) {
            LOG.debug("Sleep");
          }
          synchronized (this) {
            try {
              wait(waitTime);
@ -596,9 +593,6 @@ public class HRegionServer
              // On interrupt we go around to the while test of stopRequested
            }
          }
          if (LOG.isDebugEnabled()) {
            LOG.debug("Wake");
          }
        }
      }
    }
@ -666,7 +660,7 @@ public class HRegionServer
   * updated the meta or root regions, and the master will pick that up on its
   * next rescan of the root or meta tables.
   */
-  private void reportSplit(HRegionInfo newRegionA, HRegionInfo newRegionB) {
+  void reportSplit(HRegionInfo newRegionA, HRegionInfo newRegionB) {
    synchronized(outboundMsgs) {
      outboundMsgs.add(new HMsg(HMsg.MSG_NEW_REGION, newRegionA));
      outboundMsgs.add(new HMsg(HMsg.MSG_NEW_REGION, newRegionB));
@ -677,10 +671,10 @@ public class HRegionServer
  // HMaster-given operations
  //////////////////////////////////////////////////////////////////////////////
-  private Vector<HMsg> toDo;
+  Vector<HMsg> toDo;
  private Worker worker;
  private Thread workerThread;
-  private class Worker implements Runnable {
+  class Worker implements Runnable {
    public void stop() {
      synchronized(toDo) {
        toDo.notifyAll();
@ -700,6 +694,7 @@ public class HRegionServer
                LOG.debug("Wake on todo");
              }
            } catch(InterruptedException e) {
              // continue
            }
          }
          if(stopRequested) {
@ -761,38 +756,34 @@ public class HRegionServer
          LOG.error(e);
        }
      }
-      if(LOG.isDebugEnabled()) {
+      LOG.info("worker thread exiting");
        LOG.debug("worker thread exiting");
      }
    }
  }
-  private void openRegion(HRegionInfo regionInfo) throws IOException {
+  void openRegion(HRegionInfo regionInfo) throws IOException {
    this.lock.writeLock().lock();
    try {
      HRegion region =
        new HRegion(regionDir, log, fs, conf, regionInfo, null, oldlogfile);
-      regions.put(region.getRegionName(), region);
+      this.onlineRegions.put(region.getRegionName(), region);
      reportOpen(region); 
    } finally {
      this.lock.writeLock().unlock();
    }
  }
-  private void closeRegion(HRegionInfo info, boolean reportWhenCompleted)
+  void closeRegion(final HRegionInfo hri, final boolean reportWhenCompleted)
  throws IOException {  
    this.lock.writeLock().lock();
    HRegion region = null;
    try {
-      region = regions.remove(info.regionName);
+      region = onlineRegions.remove(hri.regionName);
    } finally {
      this.lock.writeLock().unlock();
    }
    if(region != null) {
      region.close();
      if(reportWhenCompleted) {
        reportClose(region);
      }
@ -800,12 +791,12 @@ public class HRegionServer
  }
  /** Called either when the master tells us to restart or from stop() */
-  private void closeAllRegions() {
+  void closeAllRegions() {
    Vector<HRegion> regionsToClose = new Vector<HRegion>();
    this.lock.writeLock().lock();
    try {
-      regionsToClose.addAll(regions.values());
+      regionsToClose.addAll(onlineRegions.values());
-      regions.clear();
+      onlineRegions.clear();
    } finally {
      this.lock.writeLock().unlock();
    }
@ -817,7 +808,6 @@ public class HRegionServer
      try {
        region.close();
        LOG.debug("region closed " + region.getRegionName());
      } catch(IOException e) {
        LOG.error("error closing region " + region.getRegionName(), e);
      }
@ -829,55 +819,34 @@ public class HRegionServer
  //////////////////////////////////////////////////////////////////////////////
  /** Obtain a table descriptor for the given region */
-  public HRegionInfo getRegionInfo(Text regionName) throws NotServingRegionException {
+  public HRegionInfo getRegionInfo(Text regionName)
-    HRegion region = getRegion(regionName);
+  throws NotServingRegionException {
-    return region.getRegionInfo();
+    return getRegion(regionName).getRegionInfo();
  }
  /** Get the indicated row/column */
-  public BytesWritable get(Text regionName, Text row, Text column) throws IOException {
+  public BytesWritable get(Text regionName, Text row, Text column)
-    HRegion region = getRegion(regionName);
+  throws IOException {
-    
+    return getRegion(regionName).get(row, column);
    if (LOG.isDebugEnabled()) {
      LOG.debug("get " + row.toString() + ", " + column.toString());
    }
    BytesWritable results = region.get(row, column);
    if(results != null) {
      return results;
    }
    return null;
  }
  /** Get multiple versions of the indicated row/col */
  public BytesWritable[] get(Text regionName, Text row, Text column, 
-      int numVersions) throws IOException {
+      int numVersions)
-    
+  throws IOException {
-    HRegion region = getRegion(regionName);
+    return getRegion(regionName).get(row, column, numVersions);
    BytesWritable[] results = region.get(row, column, numVersions);
    if(results != null) {
      return results;
    }
    return null;
  }
  /** Get multiple timestamped versions of the indicated row/col */
  public BytesWritable[] get(Text regionName, Text row, Text column, 
-      long timestamp, int numVersions) throws IOException {
+      long timestamp, int numVersions)
-    
+  throws IOException {
-    HRegion region = getRegion(regionName);
+    return getRegion(regionName).get(row, column, timestamp, numVersions);
    BytesWritable[] results = region.get(row, column, timestamp, numVersions);
    if(results != null) {
      return results;
    }
    return null;
  }
  /** Get all the columns (along with their names) for a given row. */
  public LabelledData[] getRow(Text regionName, Text row) throws IOException {
    HRegion region = getRegion(regionName);
    TreeMap<Text, BytesWritable> map = region.getFull(row);
    LabelledData result[] = new LabelledData[map.size()];
    int counter = 0;
@ -910,13 +879,44 @@ public class HRegionServer
    }
  }
  public LabelledData[] next(final long scannerId, final HStoreKey key)
  throws IOException {
    Text scannerName = new Text(String.valueOf(scannerId));
    HInternalScannerInterface s = scanners.get(scannerName);
    if (s == null) {
      throw new UnknownScannerException("Name: " + scannerName + ", key " +
        key);
    }
    leases.renewLease(scannerName, scannerName);
    TreeMap<Text, BytesWritable> results = new TreeMap<Text, BytesWritable>();
    ArrayList<LabelledData> values = new ArrayList<LabelledData>();
    // Keep getting rows till we find one that has at least one non-deleted
    // column value.
    while (s.next(key, results)) {
      for(Map.Entry<Text, BytesWritable> e: results.entrySet()) {
        BytesWritable val = e.getValue();
        if(val.getSize() == DELETE_BYTES.getSize()
            && val.compareTo(DELETE_BYTES) == 0) {
          // Column value is deleted. Don't return it.
          continue;
        }
        values.add(new LabelledData(e.getKey(), val));
      }
      if (values.size() > 0) {
        // Row has something in it. Let it out. Else go get another row.
        break;
      }
      // Need to clear results before we go back up and call 'next' again.
      results.clear();
    }
    return values.toArray(new LabelledData[values.size()]);
  }
  public long startUpdate(Text regionName, long clientid, Text row) 
      throws IOException {
    HRegion region = getRegion(regionName);
    long lockid = region.startUpdate(row);
-    leases.createLease(new Text(String.valueOf(clientid)), 
+    this.leases.createLease(new Text(String.valueOf(clientid)), 
        new Text(String.valueOf(lockid)), 
        new RegionListener(region, lockid));
@ -926,48 +926,36 @@ public class HRegionServer
  /** Add something to the HBase. */
  public void put(Text regionName, long clientid, long lockid, Text column, 
      BytesWritable val) throws IOException {
-    
+    HRegion region = getRegion(regionName, true);
    HRegion region = getRegion(regionName);
    leases.renewLease(new Text(String.valueOf(clientid)), 
        new Text(String.valueOf(lockid)));
    region.put(lockid, column, val);
  }
  /** Remove a cell from the HBase. */
  public void delete(Text regionName, long clientid, long lockid, Text column) 
      throws IOException {
    HRegion region = getRegion(regionName);
    leases.renewLease(new Text(String.valueOf(clientid)), 
        new Text(String.valueOf(lockid)));
    region.delete(lockid, column);
  }
  /** Abandon the transaction */
  public void abort(Text regionName, long clientid, long lockid) 
      throws IOException {
-    
+    HRegion region = getRegion(regionName, true);
    HRegion region = getRegion(regionName);
    leases.cancelLease(new Text(String.valueOf(clientid)), 
        new Text(String.valueOf(lockid)));
    region.abort(lockid);
  }
  /** Confirm the transaction */
  public void commit(Text regionName, long clientid, long lockid) 
  throws IOException {
-    
+    HRegion region = getRegion(regionName, true);
    HRegion region = getRegion(regionName);
    leases.cancelLease(new Text(String.valueOf(clientid)), 
        new Text(String.valueOf(lockid)));
    region.commit(lockid);
  }
@ -977,27 +965,55 @@ public class HRegionServer
        new Text(String.valueOf(lockid)));
  }
-  /** Private utility method for safely obtaining an HRegion handle. */
+  /** Private utility method for safely obtaining an HRegion handle.
-  private HRegion getRegion(Text regionName) throws NotServingRegionException {
+   * @param regionName Name of online {@link HRegion} to return
-    this.lock.readLock().lock();
+   * @return {@link HRegion} for <code>regionName</code>
   * @throws NotServingRegionException
   */
  private HRegion getRegion(final Text regionName)
  throws NotServingRegionException {
    return getRegion(regionName, false);
  }
  /** Private utility method for safely obtaining an HRegion handle.
   * @param regionName Name of online {@link HRegion} to return
   * @param checkRetiringRegions Set true if we're to check retiring regions
   * as well as online regions.
   * @return {@link HRegion} for <code>regionName</code>
   * @throws NotServingRegionException
   */
  private HRegion getRegion(final Text regionName,
      final boolean checkRetiringRegions)
  throws NotServingRegionException {
    HRegion region = null;
    this.lock.readLock().lock();
    try {
-      region = regions.get(regionName);
+      region = onlineRegions.get(regionName);
      if (region == null && checkRetiringRegions) {
        region = this.retiringRegions.get(regionName);
        if (LOG.isDebugEnabled()) {
          if (region != null) {
            LOG.debug("Found region " + regionName + " in retiringRegions");
          }
        }
      }
      if (region == null) {
        throw new NotServingRegionException(regionName.toString());
      }
      return region;
    } finally {
      this.lock.readLock().unlock();
    }
    if(region == null) {
      throw new NotServingRegionException(regionName.toString());
    }
    return region;
  }
  //////////////////////////////////////////////////////////////////////////////
  // remote scanner interface
  //////////////////////////////////////////////////////////////////////////////
-  private Map<Text, HInternalScannerInterface> scanners;
+  Map<Text, HInternalScannerInterface> scanners;
  private class ScannerListener extends LeaseListener {
    private Text scannerName;
@ -1006,6 +1022,7 @@ public class HRegionServer
    }
    public void leaseExpired() {
      LOG.info("Scanner " + scannerName + " lease expired");
      HInternalScannerInterface s = null;
      synchronized(scanners) {
        s = scanners.remove(scannerName);
@ -1019,7 +1036,6 @@ public class HRegionServer
  /** Start a scanner for a given HRegion. */
  public long openScanner(Text regionName, Text[] cols, Text firstRow)
  throws IOException {
    HRegion r = getRegion(regionName);
    long scannerId = -1L;
    try {
@ -1029,8 +1045,8 @@ public class HRegionServer
      synchronized(scanners) {
        scanners.put(scannerName, s);
      }
-      leases.createLease(scannerName, scannerName, new ScannerListener(scannerName));
+      leases.createLease(scannerName, scannerName,
-    
+        new ScannerListener(scannerName));
    } catch(IOException e) {
      LOG.error(e);
      throw e;
@ -1038,38 +1054,6 @@ public class HRegionServer
    return scannerId;
  }
  public LabelledData[] next(long scannerId, HStoreKey key) throws IOException {
    Text scannerName = new Text(String.valueOf(scannerId));
    HInternalScannerInterface s = scanners.get(scannerName);
    if(s == null) {
      throw new IOException("unknown scanner");
    }
    leases.renewLease(scannerName, scannerName);
    TreeMap<Text, BytesWritable> results = new TreeMap<Text, BytesWritable>();
    ArrayList<LabelledData> values = new ArrayList<LabelledData>();
    if(s.next(key, results)) {
      for(Iterator<Map.Entry<Text, BytesWritable>> it
          = results.entrySet().iterator();
          it.hasNext(); ) {
        Map.Entry<Text, BytesWritable> e = it.next();
        BytesWritable val = e.getValue();
        if(val.getSize() == DELETE_BYTES.getSize()
            && val.compareTo(DELETE_BYTES) == 0) {
          // Value is deleted. Don't return a value
          continue;
        } else {
          values.add(new LabelledData(e.getKey(), val));
        }
      }
    }
    return values.toArray(new LabelledData[values.size()]);
  }
  public void close(long scannerId) throws IOException {
    Text scannerName = new Text(String.valueOf(scannerId));
    HInternalScannerInterface s = null;
@ -1077,7 +1061,7 @@ public class HRegionServer
      s = scanners.remove(scannerName);
    }
    if(s == null) {
-      throw new IOException("unknown scanner");
+      throw new UnknownScannerException(scannerName.toString());
    }
    s.close();
    leases.cancelLease(scannerName, scannerName);
@ -1096,7 +1080,7 @@ public class HRegionServer
    System.exit(0);
  }
-  public static void main(String [] args) throws IOException {
+  public static void main(String [] args) {
    if (args.length < 1) {
      printUsageAndExit();
    }
--- a/src/java/org/apache/hadoop/hbase/HStore.java
+++ b/src/java/org/apache/hadoop/hbase/HStore.java
@ -369,8 +369,8 @@ public class HStore {
   * Compact the back-HStores.  This method may take some time, so the calling 
   * thread must be able to block for long periods.
   * 
-   * During this time, the HStore can work as usual, getting values from MapFiles
+   * During this time, the HStore can work as usual, getting values from
-   * and writing new MapFiles from given memcaches.
+   * MapFiles and writing new MapFiles from given memcaches.
   * 
   * Existing MapFiles are not destroyed until the new compacted TreeMap is 
   * completely written-out to disk.
@ -410,8 +410,7 @@ public class HStore {
        // Compute the max-sequenceID seen in any of the to-be-compacted TreeMaps
        long maxSeenSeqID = -1;
-        for(Iterator<HStoreFile> it = toCompactFiles.iterator(); it.hasNext(); ) {
+        for (HStoreFile hsf: toCompactFiles) {
          HStoreFile hsf = it.next();
          long seqid = hsf.loadInfo(fs);
          if(seqid > 0) {
            if(seqid > maxSeenSeqID) {
@ -587,7 +586,6 @@ public class HStore {
            HStoreFile hsf = it.next();
            hsf.write(out);
          }
        } finally {
          out.close();
        }
@ -595,12 +593,7 @@ public class HStore {
        // Indicate that we're done.
        Path doneFile = new Path(curCompactStore, COMPACTION_DONE);
-        out = new DataOutputStream(fs.create(doneFile));
+        (new DataOutputStream(fs.create(doneFile))).close();
        try {
        } finally {
          out.close();
        }
        // Move the compaction into place.
--- a/src/java/org/apache/hadoop/hbase/Leases.java
+++ b/src/java/org/apache/hadoop/hbase/Leases.java
@ -91,7 +91,9 @@ public class Leases {
        Lease lease = new Lease(holderId, resourceId, listener);
        Text leaseId = lease.getLeaseId();
        if(leases.get(leaseId) != null) {
-          throw new IOException("Impossible state for createLease(): Lease for holderId " + holderId + " and resourceId " + resourceId + " is still held.");
+          throw new IOException("Impossible state for createLease(): Lease " +
            "for holderId " + holderId + " and resourceId " + resourceId +
            " is still held.");
        }
        leases.put(leaseId, lease);
        sortedLeases.add(lease);
@ -106,11 +108,10 @@ public class Leases {
        Text leaseId = createLeaseId(holderId, resourceId);
        Lease lease = leases.get(leaseId);
        if(lease == null) {
          // It's possible that someone tries to renew the lease, but 
          // it just expired a moment ago.  So fail.
-          
+          throw new IOException("Cannot renew lease; not held (holderId=" +
-          throw new IOException("Cannot renew lease is not held (holderId=" + holderId + ", resourceId=" + resourceId + ")");
+            holderId + ", resourceId=" + resourceId + ")");
        }
        sortedLeases.remove(lease);
--- a/src/java/org/apache/hadoop/hbase/RegionNotFoundException.java
+++ b/src/java/org/apache/hadoop/hbase/RegionNotFoundException.java
@ -0,0 +1,30 @@
 /**
 * Copyright 2007 The Apache Software Foundation
 *
 * Licensed 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;
 import java.io.IOException;
 public class RegionNotFoundException extends IOException {
  private static final long serialVersionUID = 993179627856392526L;
  public RegionNotFoundException() {
    super();
  }
  public RegionNotFoundException(String s) {
    super(s);
  }
 }
--- a/src/java/org/apache/hadoop/hbase/RegionUnavailableListener.java
+++ b/src/java/org/apache/hadoop/hbase/RegionUnavailableListener.java
@ -19,9 +19,22 @@ import org.apache.hadoop.io.Text;
 /**
 * Used as a callback mechanism so that an HRegion can notify the HRegionServer
- * when a region is about to be closed during a split operation. This is done
+ * of the different stages making an HRegion unavailable.  Regions are made
- * to minimize the amount of time the region is off-line.
+ * unavailable during region split operations.
 */
 public interface RegionUnavailableListener {
-  public void regionIsUnavailable(Text regionName);
+  /**
   * <code>regionName</code> is closing.
   * Listener should stop accepting new writes but can continue to service
   * outstanding transactions.
   * @param regionName
   */
  public void closing(final Text regionName);
  /**
   * <code>regionName</code> is closed and no longer available.
   * Listener should clean up any references to <code>regionName</code>
   * @param regionName
   */
  public void closed(final Text regionName);
 }
--- a/src/java/org/apache/hadoop/hbase/UnknownScannerException.java
+++ b/src/java/org/apache/hadoop/hbase/UnknownScannerException.java
@ -0,0 +1,30 @@
 /**
 * Copyright 2007 The Apache Software Foundation
 *
 * Licensed 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;
 import java.io.IOException;
 public class UnknownScannerException extends IOException {
  private static final long serialVersionUID = 993179627856392526L;
  public UnknownScannerException() {
    super();
  }
  public UnknownScannerException(String s) {
    super(s);
  }
 }
--- a/src/java/org/apache/hadoop/hbase/WrongRegionException.java
+++ b/src/java/org/apache/hadoop/hbase/WrongRegionException.java
@ -0,0 +1,30 @@
 /**
 * Copyright 2007 The Apache Software Foundation
 *
 * Licensed 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;
 import java.io.IOException;
 public class WrongRegionException extends IOException {
  private static final long serialVersionUID = 993179627856392526L;
  public WrongRegionException() {
    super();
  }
  public WrongRegionException(String s) {
    super(s);
  }
 }
--- a/src/test/org/apache/hadoop/hbase/EvaluationClient.java
+++ b/src/test/org/apache/hadoop/hbase/EvaluationClient.java
@ -42,7 +42,7 @@ public class EvaluationClient implements HConstants {
  private static final int ROW_LENGTH = 1024;
-  private static final int ONE_HUNDRED_MB = 1024 * 1024 * 1 /*100 RESTORE*/;
+  private static final int ONE_HUNDRED_MB = 1024 * 1024 * 100;
  private static final int ROWS_PER_100_MB = ONE_HUNDRED_MB / ROW_LENGTH;
  private static final int ONE_GB = ONE_HUNDRED_MB * 10;
@ -62,7 +62,7 @@ public class EvaluationClient implements HConstants {
    RANDOM_WRITE,
    SEQUENTIAL_READ,
    SEQUENTIAL_WRITE,
-    SCAN};
+    SCAN}
  private Random rand;
  private Configuration conf;
@ -177,8 +177,8 @@ public class EvaluationClient implements HConstants {
          test == Test.SCAN || test == Test.SEQUENTIAL_READ ||
          test == Test.SEQUENTIAL_WRITE) {
-        for(int range = 0; range < 10; range++) {
+        for(int i = 0; i < 10; i++) {
-          long elapsedTime = sequentialWrite(range * nRows, nRows);
+          long elapsedTime = sequentialWrite(i * nRows, nRows);
          if (test == Test.SEQUENTIAL_WRITE) {
            totalElapsedTime += elapsedTime;
          }
@ -188,8 +188,8 @@ public class EvaluationClient implements HConstants {
      switch(test) {
      case RANDOM_READ:
-        for(int range = 0 ; range < 10; range++) {
+        for(int i = 0 ; i < 10; i++) {
-          long elapsedTime = randomRead(range * nRows, nRows);
+          long elapsedTime = randomRead(i * nRows, nRows);
          totalElapsedTime += elapsedTime;
        }
        System.out.print("Random read of " + R + " rows completed in: ");
@ -199,15 +199,15 @@ public class EvaluationClient implements HConstants {
        throw new UnsupportedOperationException("Not yet implemented");
      case RANDOM_WRITE:
-        for(int range = 0 ; range < 10; range++) {
+        for(int i = 0 ; i < 10; i++) {
-          long elapsedTime = randomWrite(range * nRows, nRows);
+          long elapsedTime = randomWrite(i * nRows, nRows);
          totalElapsedTime += elapsedTime;
        }
        System.out.print("Random write of " + R + " rows completed in: ");
        break;
      case SCAN:
-        for(int range = 0 ; range < 10; range++) {
+        for(int i = 0 ; i < 10; i++) {
          long elapsedTime = scan(range * nRows, nRows);
          totalElapsedTime += elapsedTime;
        }
@ -215,8 +215,8 @@ public class EvaluationClient implements HConstants {
        break;
      case SEQUENTIAL_READ:
-        for(int range = 0 ; range < 10; range++) {
+        for(int i = 0 ; i < 10; i++) {
-          long elapsedTime = sequentialRead(range * nRows, nRows);
+          long elapsedTime = sequentialRead(i * nRows, nRows);
          totalElapsedTime += elapsedTime;
        }
        System.out.print("Sequential read of " + R + " rows completed in: ");
@ -230,16 +230,16 @@ public class EvaluationClient implements HConstants {
        throw new IllegalArgumentException("Invalid command value: " + test);
      }
      System.out.println((totalElapsedTime / 1000.0));
    } catch(Exception e) {
-      e.printStackTrace();
+      LOG.error("Failed", e);
    } finally {
      LOG.info("Deleting table " + tableDescriptor.getName());
      this.client.deleteTable(tableDescriptor.getName());
    }
  }
-  private void runOneTest(Test cmd) {
+  private void runOneTest(@SuppressWarnings("unused") Test cmd) {
    // TODO
  }
  private void runTest(Test test) throws IOException {
@ -302,6 +302,10 @@ public class EvaluationClient implements HConstants {
    System.err.println("                 running: 1 <= value <= 500");
    System.err.println(" range           Integer. Required. 0 <= value <= " +
      "(nclients * 10) - 1");
    System.err.println("Examples:");
    System.err.println(" To run a single evaluation client:");
    System.err.println(" $ bin/hbase " +
      "org.apache.hadoop.hbase.EvaluationClient sequentialWrite 1 1");
  }
  private void getArgs(final int start, final String[] args) {
--- a/src/test/org/apache/hadoop/hbase/MiniHBaseCluster.java
+++ b/src/test/org/apache/hadoop/hbase/MiniHBaseCluster.java
@ -157,25 +157,20 @@ public class MiniHBaseCluster implements HConstants {
  public void shutdown() {
    LOG.info("Shutting down the HBase Cluster");
    for(int i = 0; i < regionServers.length; i++) {
      try {
      regionServers[i].stop();
      } catch(IOException e) {
        e.printStackTrace();
      }
    }
    master.shutdown();
    for(int i = 0; i < regionServers.length; i++) {
      try {
        regionThreads[i].join();
      } catch(InterruptedException e) {
        // continue
      }
    }
    try {
      masterThread.join();
    } catch(InterruptedException e) {
      // continue
    }
    LOG.info("HBase Cluster shutdown complete");
--- a/src/test/org/apache/hadoop/hbase/TestCompare.java
+++ b/src/test/org/apache/hadoop/hbase/TestCompare.java
@ -0,0 +1,33 @@
 package org.apache.hadoop.hbase;
 import org.apache.hadoop.io.Text;
 import junit.framework.TestCase;
 /**
 * Test comparing HBase objects.
 */
 public class TestCompare extends TestCase {
  public void testHRegionInfo() {
    HRegionInfo a = new HRegionInfo(1, new HTableDescriptor("a"), null, null);
    HRegionInfo b = new HRegionInfo(2, new HTableDescriptor("b"), null, null);
    assertTrue(a.compareTo(b) != 0);
    HTableDescriptor t = new HTableDescriptor("t");
    Text midway = new Text("midway");
    a = new HRegionInfo(1, t, null, midway);
    b = new HRegionInfo(2, t, midway, null);
    assertTrue(a.compareTo(b) < 0);
    assertTrue(b.compareTo(a) > 0);
    assertEquals(a, a);
    assertTrue(a.compareTo(a) == 0);
    a = new HRegionInfo(1, t, new Text("a"), new Text("d"));
    b = new HRegionInfo(2, t, new Text("e"), new Text("g"));
    assertTrue(a.compareTo(b) < 0);
    a = new HRegionInfo(1, t, new Text("aaaa"), new Text("dddd"));
    b = new HRegionInfo(2, t, new Text("e"), new Text("g"));
    assertTrue(a.compareTo(b) < 0);
    a = new HRegionInfo(1, t, new Text("aaaa"), new Text("dddd"));
    b = new HRegionInfo(2, t, new Text("aaaa"), new Text("eeee"));
    assertTrue(a.compareTo(b) < 0);
  }
 }
--- a/src/test/org/apache/hadoop/hbase/TestHRegion.java
+++ b/src/test/org/apache/hadoop/hbase/TestHRegion.java
@ -214,7 +214,7 @@ public class TestHRegion extends HBaseTestCase implements RegionUnavailableListe
          for (int i = 0; i < lockCount; i++) {
            try {
              Text rowid = new Text(Integer.toString(i));
-              lockids[i] = region.obtainLock(rowid);
+              lockids[i] = region.obtainRowLock(rowid);
              rowid.equals(region.getRowFromLock(lockids[i]));
              LOG.debug(getName() + " locked " + rowid.toString());
            } catch (IOException e) {
@ -590,8 +590,7 @@ public class TestHRegion extends HBaseTestCase implements RegionUnavailableListe
  }
  // NOTE: This test depends on testBatchWrite succeeding
-  
+  void splitAndMerge() throws IOException {
  private void splitAndMerge() throws IOException {
    Text midKey = new Text();
    if(region.needsSplit(midKey)) {
@ -634,7 +633,11 @@ public class TestHRegion extends HBaseTestCase implements RegionUnavailableListe
  /* (non-Javadoc)
   * @see org.apache.hadoop.hbase.RegionUnavailableListener#regionIsUnavailable(org.apache.hadoop.io.Text)
   */
-  public void regionIsUnavailable(Text regionName) {
+  public void closing(@SuppressWarnings("unused") final Text regionName) {
    // We don't use this here. It is only for the HRegionServer
  }
  public void closed(@SuppressWarnings("unused") final Text regionName) {
    // We don't use this here. It is only for the HRegionServer
  }
--- a/src/test/org/apache/hadoop/hbase/TestScanner.java
+++ b/src/test/org/apache/hadoop/hbase/TestScanner.java
@ -28,6 +28,9 @@ import org.apache.hadoop.io.BytesWritable;
 import org.apache.hadoop.io.DataInputBuffer;
 import org.apache.hadoop.io.Text;
 /**
 * Test of a long-lived scanner validating as we go.
 */
 public class TestScanner extends HBaseTestCase {
  private static final Text FIRST_ROW = new Text();
  private static final Text[] COLS = {
--- a/src/test/org/apache/hadoop/hbase/TestScanner2.java
+++ b/src/test/org/apache/hadoop/hbase/TestScanner2.java
@ -0,0 +1,106 @@
 package org.apache.hadoop.hbase;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.TreeMap;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.io.Text;
 /**
 * Additional scanner tests.
 * {@link TestScanner} does a custom setup/takedown not conducive
 * to addition of extra scanning tests.
 * @see TestScanner
 */
 public class TestScanner2 extends HBaseClusterTestCase {
  final Log LOG = LogFactory.getLog(this.getClass().getName());
  /**
   * Test scanning of META table around split.
   * There was a problem where only one of the splits showed in a scan.
   * Split deletes a row and then adds two new ones.
   * @throws IOException
   */
  public void testSplitDeleteOneAddTwoRegions() throws IOException {
    // First add a new table.  Its intial region will be added to META region.
    HClient client = new HClient(this.conf);
    client.createTable(new HTableDescriptor(getName()));
    List<HRegionInfo> regions = scan(client, HConstants.META_TABLE_NAME);
    assertEquals("Expected one region", regions.size(), 1);
    HRegionInfo region = regions.get(0);
    assertTrue("Expected region named for test",
      region.regionName.toString().startsWith(getName()));
    // Now do what happens at split time; remove old region and then add two
    // new ones in its place.
    HRegion.removeRegionFromMETA(client, HConstants.META_TABLE_NAME,
      region.regionName);
    HTableDescriptor desc = region.tableDesc;
    Path homedir = new Path(getName());
    List<HRegion> newRegions = new ArrayList<HRegion>(2);
    newRegions.add(HRegion.createHRegion(
      new HRegionInfo(2L, desc, null, new Text("midway")),
      homedir, this.conf, null, null));
    newRegions.add(HRegion.createHRegion(
      new HRegionInfo(3L, desc, new Text("midway"), null),
        homedir, this.conf, null, null));
    for (HRegion r: newRegions) {
      HRegion.addRegionToMETA(client, HConstants.META_TABLE_NAME, r,
        this.cluster.getHMasterAddress(), -1L);
    }
    regions = scan(client, HConstants.META_TABLE_NAME);
    assertEquals("Should be two regions only", regions.size(), 2);
  }
  private List<HRegionInfo> scan(final HClient client, final Text table)
  throws IOException {
    List<HRegionInfo> regions = new ArrayList<HRegionInfo>();
    HRegionInterface regionServer = null;
    long scannerId = -1L;
    try {
      client.openTable(table);
      HClient.RegionLocation rl = client.getRegionLocation(table);
      regionServer = client.getHRegionConnection(rl.serverAddress);
      scannerId = regionServer.openScanner(rl.regionInfo.regionName,
          HMaster.METACOLUMNS, new Text());
      while (true) {
        TreeMap<Text, byte[]> results = new TreeMap<Text, byte[]>();
        HStoreKey key = new HStoreKey();
        LabelledData[] values = regionServer.next(scannerId, key);
        if (values.length == 0) {
          break;
        }
        for (int i = 0; i < values.length; i++) {
          byte[] bytes = new byte[values[i].getData().getSize()];
          System.arraycopy(values[i].getData().get(), 0, bytes, 0,
            bytes.length);
          results.put(values[i].getLabel(), bytes);
        }
        HRegionInfo info = HRegion.getRegionInfo(results);
        String serverName = HRegion.getServerName(results);
        long startCode = HRegion.getStartCode(results);
        LOG.info(Thread.currentThread().getName() + " scanner: " +
          Long.valueOf(scannerId) + " row: " + key +
          ": regioninfo: {" + info.toString() + "}, server: " + serverName +
          ", startCode: " + startCode);
        regions.add(info);
      }
    } finally {
      try {
        if (scannerId != -1L) {
          if (regionServer != null) {
            regionServer.close(scannerId);
          }
        }
      } catch (IOException e) {
        LOG.error(e);
      }
    }
    return regions;
  }
 }