org.apache.hadoop.hbase.HRegionInfo Java Examples

private HRegion createRegion(String tableName, byte[] family, long ttl) throws IOException {
  HTableDescriptor htd = new HTableDescriptor(TableName.valueOf(tableName));
  HColumnDescriptor cfd = new HColumnDescriptor(family);
  if (ttl > 0) {
    cfd.setValue(TxConstants.PROPERTY_TTL, String.valueOf(ttl));
  }
  cfd.setMaxVersions(10);
  htd.addFamily(cfd);
  htd.addCoprocessor(TransactionProcessor.class.getName());
  Path tablePath = FSUtils.getTableDir(FSUtils.getRootDir(conf), htd.getTableName());
  FileSystem fs = FileSystem.get(conf);
  assertTrue(fs.mkdirs(tablePath));
  WALFactory walFactory = new WALFactory(conf, null, tableName + ".hlog");
  WAL hLog = walFactory.getWAL(new byte[]{1}, null);
  HRegionInfo regionInfo = new HRegionInfo(TableName.valueOf(tableName));
  HRegionFileSystem regionFS = HRegionFileSystem.createRegionOnFileSystem(conf, fs, tablePath, regionInfo);
  return new HRegion(regionFS, hLog, conf, htd,
      new LocalRegionServerServices(conf, ServerName.valueOf(
          InetAddress.getLocalHost().getHostName(), 0, System.currentTimeMillis())));
}
 

@Test
public void testBalanceDefault() throws Exception {
    splitTable("a".getBytes());

    NavigableMap<HRegionInfo, ServerName> regionLocations;
    List<Map.Entry<HRegionInfo, ServerName>> hRegionInfoList;

    try (HTable table = getTable(tableName)) {
        regionLocations = table.getRegionLocations();
        hRegionInfoList = new ArrayList<>(regionLocations.entrySet());
        Assert.assertEquals(2, regionLocations.size());
        Assert.assertEquals(hRegionInfoList.get(0).getValue(), hRegionInfoList.get(1).getValue());

        String[] argsParam = {"zookeeper", tableName, "default", "--force-proceed"};
        Args args = new ManagerArgs(argsParam);
        Assert.assertEquals("zookeeper", args.getZookeeperQuorum());
        Balance command = new Balance(admin, args);

        command.run();

        regionLocations = table.getRegionLocations();
        hRegionInfoList = new ArrayList<>(regionLocations.entrySet());
        Assert.assertEquals(2, hRegionInfoList.size());
    }
}
 

/**
 * Ensures each region of SYSTEM.CATALOG is on a different region server
 */
private static void moveRegion(HRegionInfo regionInfo, ServerName srcServerName, ServerName dstServerName) throws Exception  {
    Admin admin = driver.getConnectionQueryServices(getUrl(), TestUtil.TEST_PROPERTIES).getAdmin();
    HBaseTestingUtility util = getUtility();
    MiniHBaseCluster cluster = util.getHBaseCluster();
    HMaster master = cluster.getMaster();
    AssignmentManager am = master.getAssignmentManager();
   
    HRegionServer dstServer = util.getHBaseCluster().getRegionServer(dstServerName);
    HRegionServer srcServer = util.getHBaseCluster().getRegionServer(srcServerName);
    byte[] encodedRegionNameInBytes = regionInfo.getEncodedNameAsBytes();
    admin.move(encodedRegionNameInBytes, Bytes.toBytes(dstServer.getServerName().getServerName()));
    while (dstServer.getOnlineRegion(regionInfo.getRegionName()) == null
            || dstServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameInBytes)
            || srcServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameInBytes)) {
        // wait for the move to be finished
        Thread.sleep(100);
    }
}
 

@Test
public void testMergeEmptyFast3() throws Exception {
    makeTestData3();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty-FAST", "--force-proceed", "--test"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.run();

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(3, regionInfoList.size());
    assertArrayEquals("".getBytes(), regionInfoList.get(0).getStartKey());
    assertArrayEquals("b".getBytes(), regionInfoList.get(1).getStartKey());
    assertArrayEquals("c".getBytes(), regionInfoList.get(2).getStartKey());
}
 

@Test
public void testMergeEmpty4() throws Exception {
    makeTestData4();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty", "--force-proceed", "--test"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.setTest(true);
    command.run();
    Thread.sleep(Constant.WAIT_INTERVAL_MS);

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());
    assertArrayEquals("".getBytes(), regionInfoList.get(0).getStartKey());
}
 

private boolean isRegionBoundaryOfPhoenixSaltingTable(HRegionInfo regionInfo) {
    byte[] endKey = regionInfo.getEndKey();
    boolean boundaryRegionForPhoenix = true;

    if (endKey.length > 0) {
        for (int i = 1, limit = endKey.length; i < limit; i++) {
            if (endKey[i] != 0) {
                boundaryRegionForPhoenix = false;
                break;
            }
        }
    }

    if (boundaryRegionForPhoenix) {
        Util.printVerboseMessage(args, regionInfo.getEncodedName() + " is boundary region of phoenix : "
                + Bytes.toStringBinary(regionInfo.getStartKey()) + " ~ " + Bytes.toStringBinary(regionInfo.getEndKey()));
    }

    return boundaryRegionForPhoenix;
}
 

private void filterWithLocalityOnly(Set<byte[]> targets, String table) throws IOException {
    long startTimestamp = System.currentTimeMillis();
    Util.printVerboseMessage(args, Util.getMethodName() + " - start");

    Map<byte[], HRegionInfo> regionMap = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    for (Map.Entry<HRegionInfo, ServerName> entry : getRegionLocations(table).entrySet()) {
        byte[] regionName = entry.getKey().getRegionName();
        String serverName = entry.getValue().getHostname();
        regionMap.put(entry.getKey().getRegionName(), entry.getKey());
        regionTableMap.put(regionName, table);
        regionRSMap.put(regionName, serverName);
    }

    filterWithDataLocality(targets, regionMap);

    Util.printVerboseMessage(args, Util.getMethodName() + " - end", startTimestamp);
}
 

@Test
public void testMergeEmpty6() throws Exception {
    makeTestData6();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty", "--force-proceed", "--max-iteration=4", "--test"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.run();
    Thread.sleep(Constant.WAIT_INTERVAL_MS);

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());
}
 

@Test
public void testMergeEmptyFast2() throws Exception {
    makeTestData2();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty-FAST", "--force-proceed", "--test"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.run();

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(2, regionInfoList.size());
    assertArrayEquals("".getBytes(), regionInfoList.get(0).getStartKey());
    assertArrayEquals("a".getBytes(), regionInfoList.get(1).getStartKey());
}
 

@Test
public void testMergeEmptyFast6() throws Exception {
    makeTestData6();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty-FAST", "--force-proceed", "--test"
            , "--verbose", "--debug"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.run();

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());
}
 

private void clean(NavigableMap<HRegionInfo, ServerName> regionServerMap) throws InterruptedException, IOException {
    long timestamp = System.currentTimeMillis();

    Set<String> tableNameSet = tableNameSet(regionServerMap);

    ExecutorService executorService = Executors.newFixedThreadPool(RegionLocationCleaner.THREAD_POOL_SIZE);
    try {
        for (String tableName : tableNameSet)
            executorService.execute(
                    new RegionLocationCleaner(tableName, admin.getConfiguration(), regionServerMap));
    } finally {
        executorService.shutdown();
        executorService.awaitTermination(Long.MAX_VALUE, TimeUnit.DAYS);
    }

    Util.printVerboseMessage(args, "TableInfo.clean", timestamp);
}
 

@Test
public void testMergeEmpty4() throws Exception {
    makeTestData4();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty", "--force-proceed", "--test"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.setTest(true);
    command.run();
    Thread.sleep(Constant.WAIT_INTERVAL_MS);

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());
    assertArrayEquals("".getBytes(), regionInfoList.get(0).getStartKey());
}
 

@Override
public void regionOffline(HRegionInfo regionInfo) {
    TableName tableName = regionInfo.getTable();
    synchronized (this.colocationInfo) {
        Map<ImmutableBytesWritable, ServerName> tableKeys = this.colocationInfo.get(tableName);
        if (null == tableKeys) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("No regions of table " + tableName + " in the colocationInfo.");
            }
        } else {
            tableKeys.remove(new ImmutableBytesWritable(regionInfo.getStartKey()));
            if (LOG.isDebugEnabled()) {
                LOG.debug("The regioninfo " + regionInfo + " removed from the colocationInfo");
            }
        }
    }
}
 

@Test
public void testSplitWithHexStringDowncaseRule() throws Exception {
    List<HRegionInfo> regionInfoList;

    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());

    String[] argsParam = {"zookeeper", tableName, "Rule", "hexString_down", "5", "--force-proceed"};
    Args args = new ManagerArgs(argsParam);
    assertEquals("zookeeper", args.getZookeeperQuorum());
    Split command = new Split(admin, args);

    command.run();
    waitForSplitting(5);

    regionInfoList = getRegionInfoList(tableName);
    assertEquals(5, regionInfoList.size());
    for (HRegionInfo hRegionInfo : regionInfoList) {
        byte[] startKey = hRegionInfo.getStartKey();
        if (startKey.length > 0) {
            assertTrue(Bytes.toString(startKey).matches("[a-z0-9]*"));
            assertFalse(Bytes.toString(startKey).matches("[A-Z]*"));
        }
    }
}
 

protected void makeTestData7() throws Exception {
    List<HRegionInfo> regionInfoList;

    // create tables
    String tableName2 = createAdditionalTable(TestBase.tableName + "2");
    String tableName3 = createAdditionalTable(TestBase.tableName + "3");

    // split tables
    splitTable(tableName, "a".getBytes());
    splitTable(tableName, "b".getBytes());
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(3, regionInfoList.size());

    splitTable(tableName2, "a".getBytes());
    splitTable(tableName2, "b".getBytes());
    regionInfoList = getRegionInfoList(tableName2);
    assertEquals(3, regionInfoList.size());

    splitTable(tableName3, "a".getBytes());
    splitTable(tableName3, "b".getBytes());
    regionInfoList = getRegionInfoList(tableName3);
    assertEquals(3, regionInfoList.size());
}
 

@SuppressWarnings("UnusedParameters")
private static NavigableMap<HRegionInfo, ServerName> regionServerMap(Args args, Configuration conf, HConnection connection, final String tableNameParam, final boolean offlined) throws IOException {
    long timestamp = System.currentTimeMillis();

    final NavigableMap<HRegionInfo, ServerName> regions = new TreeMap<>();
    TableName tableName = TableName.valueOf(tableNameParam);
    MetaScanner.MetaScannerVisitor visitor = new MetaScanner.TableMetaScannerVisitor(tableName) {
        @Override
        public boolean processRowInternal(Result rowResult) throws IOException {
            HRegionInfo info = HRegionInfo.getHRegionInfo(rowResult);
            ServerName serverName = HRegionInfo.getServerName(rowResult);

            if (info.isOffline() && !offlined) return true;
            regions.put(info, serverName);
            return true;
        }
    };
    MetaScanner.metaScan(connection, visitor, tableName);

    Util.printVerboseMessage(args, "CommandAdapter.allTableRegions", timestamp);
    return regions;
}
 

public static boolean isReallyEmptyRegion(HConnection connection,
    String tableName, HRegionInfo regionInfo) throws IOException {
    boolean emptyRegion = false;
    // verify really empty region by scanning records
    try (HTableInterface table = connection.getTable(tableName)) {
        Scan scan = new Scan(regionInfo.getStartKey(), regionInfo.getEndKey());
        FilterList filterList = new FilterList();
        filterList.addFilter(new KeyOnlyFilter());
        filterList.addFilter(new FirstKeyOnlyFilter());
        scan.setFilter(filterList);
        scan.setCacheBlocks(false);
        scan.setSmall(true);
        scan.setCaching(1);

        try (ResultScanner scanner = table.getScanner(scan)) {
            if (scanner.next() == null) emptyRegion = true;
        }
    }
    return emptyRegion;
}
 

/**
 * If the table is spread across multiple region servers, then we parallelize the scan by making each region server a split.
 *
 * @see GlueMetadataHandler
 */
@Override
public GetSplitsResponse doGetSplits(BlockAllocator blockAllocator, GetSplitsRequest request)
        throws IOException
{
    Set<Split> splits = new HashSet<>();

    //We can read each region in parallel
    for (HRegionInfo info : getOrCreateConn(request).getTableRegions(HbaseSchemaUtils.getQualifiedTable(request.getTableName()))) {
        Split.Builder splitBuilder = Split.newBuilder(makeSpillLocation(request), makeEncryptionKey())
                .add(HBASE_CONN_STR, getConnStr(request))
                .add(START_KEY_FIELD, new String(info.getStartKey()))
                .add(END_KEY_FIELD, new String(info.getEndKey()))
                .add(REGION_ID_FIELD, String.valueOf(info.getRegionId()))
                .add(REGION_NAME_FIELD, info.getRegionNameAsString());

        splits.add(splitBuilder.build());
    }

    return new GetSplitsResponse(request.getCatalogName(), splits, null);
}
 

@Test
public void testSplitWithDecimalString() throws Exception {
    List<HRegionInfo> regionInfoList;

    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());

    String[] argsParam = {"zookeeper", tableName, "Rule", "decimalString", "3", "10", "--force-proceed"};
    Args args = new ManagerArgs(argsParam);
    assertEquals("zookeeper", args.getZookeeperQuorum());
    Split command = new Split(admin, args);

    command.run();
    waitForSplitting(3);

    regionInfoList = getRegionInfoList(tableName);
    assertEquals(3, regionInfoList.size());
    for (HRegionInfo hRegionInfo : regionInfoList) {
        byte[] startKey = hRegionInfo.getStartKey();
        if (startKey.length > 0) {
            assertTrue(Bytes.toString(startKey).matches("[0-9]*"));
            assertFalse(Bytes.toString(startKey).matches("[A-Za-z]*"));
        }
    }
}
 

public static boolean isReallyEmptyRegion(HConnection connection,
    String tableName, HRegionInfo regionInfo) throws IOException {
    boolean emptyRegion = false;
    // verify really empty region by scanning records
    try (HTableInterface table = connection.getTable(tableName)) {
        Scan scan = new Scan(regionInfo.getStartKey(), regionInfo.getEndKey());
        FilterList filterList = new FilterList();
        filterList.addFilter(new KeyOnlyFilter());
        filterList.addFilter(new FirstKeyOnlyFilter());
        scan.setFilter(filterList);
        scan.setCacheBlocks(false);
        scan.setSmall(true);
        scan.setCaching(1);

        try (ResultScanner scanner = table.getScanner(scan)) {
            if (scanner.next() == null) emptyRegion = true;
        }
    }
    return emptyRegion;
}
 

protected SortedSet<byte[]> getTransactionalRegions() throws IOException {
  SortedSet<byte[]> regions = new TreeSet<>(Bytes.BYTES_COMPARATOR);
  try (Admin admin = connection.getAdmin()) {
    HTableDescriptor[] tableDescriptors = admin.listTables();
    LOG.debug("Got {} tables to process", tableDescriptors == null ? 0 : tableDescriptors.length);
    if (tableDescriptors != null) {
      for (HTableDescriptor tableDescriptor : tableDescriptors) {
        if (isTransactionalTable(tableDescriptor)) {
          List<HRegionInfo> tableRegions = admin.getTableRegions(tableDescriptor.getTableName());
          LOG.debug("Regions for table {}: {}", tableDescriptor.getTableName(), tableRegions);
          if (tableRegions != null) {
            for (HRegionInfo region : tableRegions) {
              regions.add(region.getRegionName());
            }
          }
        } else {
          LOG.debug("{} is not a transactional table", tableDescriptor.getTableName());
        }
      }
    }
  }
  return regions;
}
 

@Test
public void testMergeEmpty2() throws Exception {
    makeTestData2();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty", "--force-proceed"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.setTest(true);
    command.run();
    Thread.sleep(Constant.WAIT_INTERVAL_MS);

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());
    assertArrayEquals("".getBytes(), regionInfoList.get(0).getStartKey());
}
 

protected void makeTestData7() throws Exception {
    List<HRegionInfo> regionInfoList;

    // create tables
    String tableName2 = createAdditionalTable(TestBase.tableName + "2");
    String tableName3 = createAdditionalTable(TestBase.tableName + "3");

    // split tables
    splitTable(tableName, "a".getBytes());
    splitTable(tableName, "b".getBytes());
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(3, regionInfoList.size());

    splitTable(tableName2, "a".getBytes());
    splitTable(tableName2, "b".getBytes());
    regionInfoList = getRegionInfoList(tableName2);
    assertEquals(3, regionInfoList.size());

    splitTable(tableName3, "a".getBytes());
    splitTable(tableName3, "b".getBytes());
    regionInfoList = getRegionInfoList(tableName3);
    assertEquals(3, regionInfoList.size());
}
 

@Test
public void testMergeEmptyFast3() throws Exception {
    makeTestData3();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty-FAST", "--force-proceed", "--test"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.run();

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(3, regionInfoList.size());
    assertArrayEquals("".getBytes(), regionInfoList.get(0).getStartKey());
    assertArrayEquals("b".getBytes(), regionInfoList.get(1).getStartKey());
    assertArrayEquals("c".getBytes(), regionInfoList.get(2).getStartKey());
}
 

@Test
public void testColumnStatsMerge() throws Exception {

    // split a region
    try (Admin admin = connection.getAdmin()) {
      HRegionInfo regionInfo = regionInfoList.get(1);
      admin.splitRegion(regionInfo.getEncodedNameAsBytes());

      regionInfoList = admin.getTableRegions(hTableName);
      long totalWaitingTime = 1000 * 60;
      long waitUnit = 2000;
      while (regionInfoList.size() == 2 && totalWaitingTime > 0) {
        totalWaitingTime -= waitUnit;
        Thread.sleep(waitUnit);
        regionInfoList = admin.getTableRegions(hTableName);
      }

      PreparedStatement ps = methodWatcher.prepareStatement("explain select * from t a, t b where a.c2=b.c2");
      ResultSet rs = ps.executeQuery();
      int count = 0;
      while (rs.next()) {
        count++;
      }
      Assert.assertTrue(count > 0);
    }
}
 

@Test
public void testMergeEmpty6() throws Exception {
    makeTestData6();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty", "--force-proceed", "--max-iteration=4", "--test"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.run();
    Thread.sleep(Constant.WAIT_INTERVAL_MS);

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());
}
 

private static NavigableMap<HRegionInfo, ServerName> regionServerMap(Args args, Configuration conf,
    HConnection connection, final String tableNameParam, final boolean offlined) throws IOException {
    long timestamp = System.currentTimeMillis();

    final NavigableMap<HRegionInfo, ServerName> regions = new TreeMap<>();
    TableName tableName = TableName.valueOf(tableNameParam);
    MetaScanner.MetaScannerVisitor visitor = new MetaScanner.TableMetaScannerVisitor(tableName) {
        @Override
        public boolean processRowInternal(Result rowResult) throws IOException {
            HRegionInfo info = HRegionInfo.getHRegionInfo(rowResult);
            ServerName serverName = HRegionInfo.getServerName(rowResult);

            if (info.isOffline() && !offlined) return true;
            regions.put(info, serverName);
            return true;
        }
    };
    MetaScanner.metaScan(conf, connection, visitor, tableName);

    Util.printVerboseMessage(args, "CommandAdapter.regionServerMap", timestamp);
    return regions;
}
 

@Test
public void testMergeEmpty6() throws Exception {
    makeTestData6();

    List<HRegionInfo> regionInfoList;

    // merge
    String[] argsParam = {"zookeeper", tableName, "empty", "--force-proceed", "--max-iteration=4", "--test"};
    Args args = new ManagerArgs(argsParam);
    Merge command = new Merge(admin, args);
    command.run();
    Thread.sleep(Constant.WAIT_INTERVAL_MS);

    // check
    Thread.sleep(Constant.SMALL_WAIT_INTERVAL_MS);
    regionInfoList = getRegionInfoList(tableName);
    assertEquals(1, regionInfoList.size());
}
 

@Test
public void testGetOnlineRegions() throws Exception {
    createAdditionalTable(tableName + "2");

    int regionCount = 0;
    for (ServerName serverName : admin.getClusterStatus().getServers()) {
        for (HRegionInfo hRegionInfo : admin.getOnlineRegions(serverName)) {
            System.out.println(hRegionInfo);
            regionCount++;
        }
    }

    if (miniCluster) {
        if (securedCluster) {
            Assert.assertEquals(5, regionCount);
        } else {
            Assert.assertEquals(4, regionCount);
        }
    }
}
 

public static List<RegionPlan> makePlan(HBaseAdmin admin, List<RegionPlan> newRegionPlan) throws IOException {
    // snapshot current region assignment
    Map<HRegionInfo, ServerName> regionAssignmentMap = createRegionAssignmentMap(admin);

    // update with new plan
    for (RegionPlan regionPlan : newRegionPlan) {
        regionAssignmentMap.put(regionPlan.getRegionInfo(), regionPlan.getDestination());
    }

    Map<ServerName, List<HRegionInfo>> clusterState = initializeRegionMap(admin);
    for (Map.Entry<HRegionInfo, ServerName> entry : regionAssignmentMap.entrySet())
        clusterState.get(entry.getValue()).add(entry.getKey());

    StochasticLoadBalancer balancer = new StochasticLoadBalancer();
    Configuration conf = admin.getConfiguration();
    conf.setFloat("hbase.regions.slop", 0.2f);
    balancer.setConf(conf);
    return balancer.balanceCluster(clusterState);
}