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Posted to commits@hbase.apache.org by sy...@apache.org on 2016/02/27 00:09:32 UTC

[11/37] hbase git commit: HBASE-15302 Reenable the other tests disabled by HBASE-14678

http://git-wip-us.apache.org/repos/asf/hbase/blob/30cec72f/hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestDistributedLogSplitting.java
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diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestDistributedLogSplitting.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestDistributedLogSplitting.java
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@@ -0,0 +1,1799 @@
+/**
+ *
+
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master;
+
+import static org.apache.hadoop.hbase.SplitLogCounters.tot_mgr_wait_for_zk_delete;
+import static org.apache.hadoop.hbase.SplitLogCounters.tot_wkr_final_transition_failed;
+import static org.apache.hadoop.hbase.SplitLogCounters.tot_wkr_preempt_task;
+import static org.apache.hadoop.hbase.SplitLogCounters.tot_wkr_task_acquired;
+import static org.apache.hadoop.hbase.SplitLogCounters.tot_wkr_task_done;
+import static org.apache.hadoop.hbase.SplitLogCounters.tot_wkr_task_err;
+import static org.apache.hadoop.hbase.SplitLogCounters.tot_wkr_task_resigned;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.NavigableSet;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.PathFilter;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HColumnDescriptor;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.MiniHBaseCluster;
+import org.apache.hadoop.hbase.NamespaceDescriptor;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.SplitLogCounters;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.Waiter;
+import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.ConnectionUtils;
+import org.apache.hadoop.hbase.client.Delete;
+import org.apache.hadoop.hbase.client.Get;
+import org.apache.hadoop.hbase.client.Increment;
+import org.apache.hadoop.hbase.client.NonceGenerator;
+import org.apache.hadoop.hbase.client.PerClientRandomNonceGenerator;
+import org.apache.hadoop.hbase.client.Put;
+import org.apache.hadoop.hbase.client.RegionLocator;
+import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.client.RetriesExhaustedWithDetailsException;
+import org.apache.hadoop.hbase.client.Table;
+import org.apache.hadoop.hbase.coordination.BaseCoordinatedStateManager;
+import org.apache.hadoop.hbase.coordination.ZKSplitLogManagerCoordination;
+import org.apache.hadoop.hbase.exceptions.OperationConflictException;
+import org.apache.hadoop.hbase.exceptions.RegionInRecoveryException;
+import org.apache.hadoop.hbase.ipc.ServerNotRunningYetException;
+import org.apache.hadoop.hbase.master.SplitLogManager.TaskBatch;
+import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
+import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.GetRegionInfoResponse.CompactionState;
+import org.apache.hadoop.hbase.regionserver.HRegion;
+import org.apache.hadoop.hbase.regionserver.HRegionServer;
+import org.apache.hadoop.hbase.regionserver.Region;
+import org.apache.hadoop.hbase.regionserver.wal.HLogKey;
+import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
+import org.apache.hadoop.hbase.testclassification.LargeTests;
+import org.apache.hadoop.hbase.testclassification.MasterTests;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.apache.hadoop.hbase.util.JVMClusterUtil.MasterThread;
+import org.apache.hadoop.hbase.util.JVMClusterUtil.RegionServerThread;
+import org.apache.hadoop.hbase.util.Threads;
+import org.apache.hadoop.hbase.wal.DefaultWALProvider;
+import org.apache.hadoop.hbase.wal.WAL;
+import org.apache.hadoop.hbase.wal.WALFactory;
+import org.apache.hadoop.hbase.wal.WALSplitter;
+import org.apache.hadoop.hbase.zookeeper.MiniZooKeeperCluster;
+import org.apache.hadoop.hbase.zookeeper.ZKUtil;
+import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category({MasterTests.class, LargeTests.class})
+@SuppressWarnings("deprecation")
+public class TestDistributedLogSplitting {
+  private static final Log LOG = LogFactory.getLog(TestSplitLogManager.class);
+  static {
+    // Uncomment the following line if more verbosity is needed for
+    // debugging (see HBASE-12285 for details).
+    //Logger.getLogger("org.apache.hadoop.hbase").setLevel(Level.DEBUG);
+
+    // test ThreeRSAbort fails under hadoop2 (2.0.2-alpha) if shortcircuit-read (scr) is on. this
+    // turns it off for this test.  TODO: Figure out why scr breaks recovery.
+    System.setProperty("hbase.tests.use.shortcircuit.reads", "false");
+
+  }
+
+  // Start a cluster with 2 masters and 6 regionservers
+  static final int NUM_MASTERS = 2;
+  static final int NUM_RS = 5;
+
+  MiniHBaseCluster cluster;
+  HMaster master;
+  Configuration conf;
+  static Configuration originalConf;
+  static HBaseTestingUtility TEST_UTIL;
+  static MiniDFSCluster dfsCluster;
+  static MiniZooKeeperCluster zkCluster;
+
+  @BeforeClass
+  public static void setup() throws Exception {
+    TEST_UTIL = new HBaseTestingUtility(HBaseConfiguration.create());
+    dfsCluster = TEST_UTIL.startMiniDFSCluster(1);
+    zkCluster = TEST_UTIL.startMiniZKCluster();
+    originalConf = TEST_UTIL.getConfiguration();
+  }
+
+  @AfterClass
+  public static void tearDown() throws IOException {
+    TEST_UTIL.shutdownMiniZKCluster();
+    TEST_UTIL.shutdownMiniDFSCluster();
+    TEST_UTIL.shutdownMiniHBaseCluster();
+  }
+
+  private void startCluster(int num_rs) throws Exception {
+    SplitLogCounters.resetCounters();
+    LOG.info("Starting cluster");
+    conf.getLong("hbase.splitlog.max.resubmit", 0);
+    // Make the failure test faster
+    conf.setInt("zookeeper.recovery.retry", 0);
+    conf.setInt(HConstants.REGIONSERVER_INFO_PORT, -1);
+    conf.setFloat(HConstants.LOAD_BALANCER_SLOP_KEY, (float) 100.0); // no load balancing
+    conf.setInt("hbase.regionserver.wal.max.splitters", 3);
+    conf.setInt(HConstants.REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT, 10);
+    TEST_UTIL.shutdownMiniHBaseCluster();
+    TEST_UTIL = new HBaseTestingUtility(conf);
+    TEST_UTIL.setDFSCluster(dfsCluster);
+    TEST_UTIL.setZkCluster(zkCluster);
+    TEST_UTIL.startMiniHBaseCluster(NUM_MASTERS, num_rs);
+    cluster = TEST_UTIL.getHBaseCluster();
+    LOG.info("Waiting for active/ready master");
+    cluster.waitForActiveAndReadyMaster();
+    master = cluster.getMaster();
+    while (cluster.getLiveRegionServerThreads().size() < num_rs) {
+      Threads.sleep(10);
+    }
+  }
+
+  @Before
+  public void before() throws Exception {
+    // refresh configuration
+    conf = HBaseConfiguration.create(originalConf);
+  }
+
+  @After
+  public void after() throws Exception {
+    try {
+      if (TEST_UTIL.getHBaseCluster() != null) {
+        for (MasterThread mt : TEST_UTIL.getHBaseCluster().getLiveMasterThreads()) {
+          mt.getMaster().abort("closing...", null);
+        }
+      }
+      TEST_UTIL.shutdownMiniHBaseCluster();
+    } finally {
+      TEST_UTIL.getTestFileSystem().delete(FSUtils.getRootDir(TEST_UTIL.getConfiguration()), true);
+      ZKUtil.deleteNodeRecursively(TEST_UTIL.getZooKeeperWatcher(), "/hbase");
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test (timeout=300000)
+  public void testRecoveredEdits() throws Exception {
+    LOG.info("testRecoveredEdits");
+    conf.setLong("hbase.regionserver.hlog.blocksize", 30 * 1024); // create more than one wal
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, false);
+    startCluster(NUM_RS);
+
+    final int NUM_LOG_LINES = 1000;
+    final SplitLogManager slm = master.getMasterFileSystem().splitLogManager;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+    FileSystem fs = master.getMasterFileSystem().getFileSystem();
+
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+
+    Path rootdir = FSUtils.getRootDir(conf);
+
+    Table t = installTable(new ZooKeeperWatcher(conf, "table-creation", null),
+        "table", "family", 40);
+    try {
+      TableName table = t.getName();
+      List<HRegionInfo> regions = null;
+      HRegionServer hrs = null;
+      for (int i = 0; i < NUM_RS; i++) {
+        boolean foundRs = false;
+        hrs = rsts.get(i).getRegionServer();
+        regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+        for (HRegionInfo region : regions) {
+          if (region.getTable().getNameAsString().equalsIgnoreCase("table")) {
+            foundRs = true;
+            break;
+          }
+        }
+        if (foundRs) break;
+      }
+      final Path logDir = new Path(rootdir, DefaultWALProvider.getWALDirectoryName(hrs
+          .getServerName().toString()));
+
+      LOG.info("#regions = " + regions.size());
+      Iterator<HRegionInfo> it = regions.iterator();
+      while (it.hasNext()) {
+        HRegionInfo region = it.next();
+        if (region.getTable().getNamespaceAsString()
+            .equals(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR)) {
+          it.remove();
+        }
+      }
+
+      makeWAL(hrs, regions, "table", "family", NUM_LOG_LINES, 100);
+
+      slm.splitLogDistributed(logDir);
+
+      int count = 0;
+      for (HRegionInfo hri : regions) {
+
+        Path tdir = FSUtils.getTableDir(rootdir, table);
+        Path editsdir =
+            WALSplitter.getRegionDirRecoveredEditsDir(
+                HRegion.getRegionDir(tdir, hri.getEncodedName()));
+        LOG.debug("checking edits dir " + editsdir);
+        FileStatus[] files = fs.listStatus(editsdir, new PathFilter() {
+          @Override
+          public boolean accept(Path p) {
+            if (WALSplitter.isSequenceIdFile(p)) {
+              return false;
+            }
+            return true;
+          }
+        });
+        assertTrue(
+            "edits dir should have more than a single file in it. instead has " + files.length,
+            files.length > 1);
+        for (int i = 0; i < files.length; i++) {
+          int c = countWAL(files[i].getPath(), fs, conf);
+          count += c;
+        }
+        LOG.info(count + " edits in " + files.length + " recovered edits files.");
+      }
+
+      // check that the log file is moved
+      assertFalse(fs.exists(logDir));
+
+      assertEquals(NUM_LOG_LINES, count);
+    } finally {
+      if (t != null) t.close();
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testLogReplayWithNonMetaRSDown() throws Exception {
+    LOG.info("testLogReplayWithNonMetaRSDown");
+    conf.setLong("hbase.regionserver.hlog.blocksize", 30 * 1024); // create more than one wal
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_LOG_LINES = 1000;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      HRegionServer hrs = findRSToKill(false, "table");
+      List<HRegionInfo> regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+      makeWAL(hrs, regions, "table", "family", NUM_LOG_LINES, 100);
+
+      // wait for abort completes
+      this.abortRSAndVerifyRecovery(hrs, ht, zkw, NUM_REGIONS_TO_CREATE, NUM_LOG_LINES);
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  private static class NonceGeneratorWithDups extends PerClientRandomNonceGenerator {
+    private boolean isDups = false;
+    private LinkedList<Long> nonces = new LinkedList<Long>();
+
+    public void startDups() {
+      isDups = true;
+    }
+
+    @Override
+    public long newNonce() {
+      long nonce = isDups ? nonces.removeFirst() : super.newNonce();
+      if (!isDups) {
+        nonces.add(nonce);
+      }
+      return nonce;
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testNonceRecovery() throws Exception {
+    LOG.info("testNonceRecovery");
+    final String TABLE_NAME = "table";
+    final String FAMILY_NAME = "family";
+    final int NUM_REGIONS_TO_CREATE = 40;
+
+    conf.setLong("hbase.regionserver.hlog.blocksize", 100*1024);
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+    master.balanceSwitch(false);
+
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, TABLE_NAME, FAMILY_NAME, NUM_REGIONS_TO_CREATE);
+    NonceGeneratorWithDups ng = new NonceGeneratorWithDups();
+    NonceGenerator oldNg =
+        ConnectionUtils.injectNonceGeneratorForTesting(
+            (ClusterConnection)TEST_UTIL.getConnection(), ng);
+
+    try {
+      List<Increment> reqs = new ArrayList<Increment>();
+      for (RegionServerThread rst : cluster.getLiveRegionServerThreads()) {
+        HRegionServer hrs = rst.getRegionServer();
+        List<HRegionInfo> hris = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+        for (HRegionInfo hri : hris) {
+          if (TABLE_NAME.equalsIgnoreCase(hri.getTable().getNameAsString())) {
+            byte[] key = hri.getStartKey();
+            if (key == null || key.length == 0) {
+              key = Bytes.copy(hri.getEndKey());
+              --(key[key.length - 1]);
+            }
+            Increment incr = new Increment(key);
+            incr.addColumn(Bytes.toBytes(FAMILY_NAME), Bytes.toBytes("q"), 1);
+            ht.increment(incr);
+            reqs.add(incr);
+          }
+        }
+      }
+
+      HRegionServer hrs = findRSToKill(false, "table");
+      abortRSAndWaitForRecovery(hrs, zkw, NUM_REGIONS_TO_CREATE);
+      ng.startDups();
+      for (Increment incr : reqs) {
+        try {
+          ht.increment(incr);
+          fail("should have thrown");
+        } catch (OperationConflictException ope) {
+          LOG.debug("Caught as expected: " + ope.getMessage());
+        }
+      }
+    } finally {
+      ConnectionUtils.injectNonceGeneratorForTesting((ClusterConnection)
+          TEST_UTIL.getConnection(), oldNg);
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testLogReplayWithMetaRSDown() throws Exception {
+    LOG.info("testRecoveredEditsReplayWithMetaRSDown");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_LOG_LINES = 1000;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      HRegionServer hrs = findRSToKill(true, "table");
+      List<HRegionInfo> regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+      makeWAL(hrs, regions, "table", "family", NUM_LOG_LINES, 100);
+
+      this.abortRSAndVerifyRecovery(hrs, ht, zkw, NUM_REGIONS_TO_CREATE, NUM_LOG_LINES);
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  private void abortRSAndVerifyRecovery(HRegionServer hrs, Table ht, final ZooKeeperWatcher zkw,
+      final int numRegions, final int numofLines) throws Exception {
+
+    abortRSAndWaitForRecovery(hrs, zkw, numRegions);
+    assertEquals(numofLines, TEST_UTIL.countRows(ht));
+  }
+
+  private void abortRSAndWaitForRecovery(HRegionServer hrs, final ZooKeeperWatcher zkw,
+      final int numRegions) throws Exception {
+    final MiniHBaseCluster tmpCluster = this.cluster;
+
+    // abort RS
+    LOG.info("Aborting region server: " + hrs.getServerName());
+    hrs.abort("testing");
+
+    // wait for abort completes
+    TEST_UTIL.waitFor(120000, 200, new Waiter.Predicate<Exception>() {
+      @Override
+      public boolean evaluate() throws Exception {
+        return (tmpCluster.getLiveRegionServerThreads().size() <= (NUM_RS - 1));
+      }
+    });
+
+    // wait for regions come online
+    TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+      @Override
+      public boolean evaluate() throws Exception {
+        return (HBaseTestingUtility.getAllOnlineRegions(tmpCluster).size()
+            >= (numRegions + 1));
+      }
+    });
+
+    // wait for all regions are fully recovered
+    TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+      @Override
+      public boolean evaluate() throws Exception {
+        List<String> recoveringRegions = zkw.getRecoverableZooKeeper().getChildren(
+            zkw.recoveringRegionsZNode, false);
+        return (recoveringRegions != null && recoveringRegions.size() == 0);
+      }
+    });
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testMasterStartsUpWithLogSplittingWork() throws Exception {
+    LOG.info("testMasterStartsUpWithLogSplittingWork");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, false);
+    conf.setInt(ServerManager.WAIT_ON_REGIONSERVERS_MINTOSTART, NUM_RS - 1);
+    startCluster(NUM_RS);
+
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_LOG_LINES = 1000;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      HRegionServer hrs = findRSToKill(false, "table");
+      List<HRegionInfo> regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+      makeWAL(hrs, regions, "table", "family", NUM_LOG_LINES, 100);
+
+      // abort master
+      abortMaster(cluster);
+
+      // abort RS
+      LOG.info("Aborting region server: " + hrs.getServerName());
+      hrs.abort("testing");
+
+      // wait for abort completes
+      TEST_UTIL.waitFor(120000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (cluster.getLiveRegionServerThreads().size() <= (NUM_RS - 1));
+        }
+      });
+
+      Thread.sleep(2000);
+      LOG.info("Current Open Regions:"
+          + HBaseTestingUtility.getAllOnlineRegions(cluster).size());
+
+      // wait for abort completes
+      TEST_UTIL.waitFor(120000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (HBaseTestingUtility.getAllOnlineRegions(cluster).size()
+              >= (NUM_REGIONS_TO_CREATE + 1));
+        }
+      });
+
+      LOG.info("Current Open Regions After Master Node Starts Up:"
+          + HBaseTestingUtility.getAllOnlineRegions(cluster).size());
+
+      assertEquals(NUM_LOG_LINES, TEST_UTIL.countRows(ht));
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testMasterStartsUpWithLogReplayWork() throws Exception {
+    LOG.info("testMasterStartsUpWithLogReplayWork");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    conf.setInt(ServerManager.WAIT_ON_REGIONSERVERS_MINTOSTART, NUM_RS - 1);
+    startCluster(NUM_RS);
+
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_LOG_LINES = 1000;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      HRegionServer hrs = findRSToKill(false, "table");
+      List<HRegionInfo> regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+      makeWAL(hrs, regions, "table", "family", NUM_LOG_LINES, 100);
+
+      // abort master
+      abortMaster(cluster);
+
+      // abort RS
+      LOG.info("Aborting region server: " + hrs.getServerName());
+      hrs.abort("testing");
+
+      // wait for the RS dies
+      TEST_UTIL.waitFor(120000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (cluster.getLiveRegionServerThreads().size() <= (NUM_RS - 1));
+        }
+      });
+
+      Thread.sleep(2000);
+      LOG.info("Current Open Regions:" + HBaseTestingUtility.getAllOnlineRegions(cluster).size());
+
+      // wait for all regions are fully recovered
+      TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          List<String> recoveringRegions = zkw.getRecoverableZooKeeper().getChildren(
+              zkw.recoveringRegionsZNode, false);
+          boolean done = recoveringRegions != null && recoveringRegions.size() == 0;
+          if (!done) {
+            LOG.info("Recovering regions: " + recoveringRegions);
+          }
+          return done;
+        }
+      });
+
+      LOG.info("Current Open Regions After Master Node Starts Up:"
+          + HBaseTestingUtility.getAllOnlineRegions(cluster).size());
+
+      assertEquals(NUM_LOG_LINES, TEST_UTIL.countRows(ht));
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testLogReplayTwoSequentialRSDown() throws Exception {
+    LOG.info("testRecoveredEditsReplayTwoSequentialRSDown");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_LOG_LINES = 1000;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      List<HRegionInfo> regions = null;
+      HRegionServer hrs1 = findRSToKill(false, "table");
+      regions = ProtobufUtil.getOnlineRegions(hrs1.getRSRpcServices());
+
+      makeWAL(hrs1, regions, "table", "family", NUM_LOG_LINES, 100);
+
+      // abort RS1
+      LOG.info("Aborting region server: " + hrs1.getServerName());
+      hrs1.abort("testing");
+
+      // wait for abort completes
+      TEST_UTIL.waitFor(120000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (cluster.getLiveRegionServerThreads().size() <= (NUM_RS - 1));
+        }
+      });
+
+      // wait for regions come online
+      TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (HBaseTestingUtility.getAllOnlineRegions(cluster).size()
+              >= (NUM_REGIONS_TO_CREATE + 1));
+        }
+      });
+
+      // sleep a little bit in order to interrupt recovering in the middle
+      Thread.sleep(300);
+      // abort second region server
+      rsts = cluster.getLiveRegionServerThreads();
+      HRegionServer hrs2 = rsts.get(0).getRegionServer();
+      LOG.info("Aborting one more region server: " + hrs2.getServerName());
+      hrs2.abort("testing");
+
+      // wait for abort completes
+      TEST_UTIL.waitFor(120000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (cluster.getLiveRegionServerThreads().size() <= (NUM_RS - 2));
+        }
+      });
+
+      // wait for regions come online
+      TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (HBaseTestingUtility.getAllOnlineRegions(cluster).size()
+              >= (NUM_REGIONS_TO_CREATE + 1));
+        }
+      });
+
+      // wait for all regions are fully recovered
+      TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          List<String> recoveringRegions = zkw.getRecoverableZooKeeper().getChildren(
+              zkw.recoveringRegionsZNode, false);
+          return (recoveringRegions != null && recoveringRegions.size() == 0);
+        }
+      });
+
+      assertEquals(NUM_LOG_LINES, TEST_UTIL.countRows(ht));
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testMarkRegionsRecoveringInZK() throws Exception {
+    LOG.info("testMarkRegionsRecoveringInZK");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+    master.balanceSwitch(false);
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    final ZooKeeperWatcher zkw = master.getZooKeeper();
+    Table ht = installTable(zkw, "table", "family", 40);
+    try {
+      final SplitLogManager slm = master.getMasterFileSystem().splitLogManager;
+
+      Set<HRegionInfo> regionSet = new HashSet<HRegionInfo>();
+      HRegionInfo region = null;
+      HRegionServer hrs = null;
+      ServerName firstFailedServer = null;
+      ServerName secondFailedServer = null;
+      for (int i = 0; i < NUM_RS; i++) {
+        hrs = rsts.get(i).getRegionServer();
+        List<HRegionInfo> regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+        if (regions.isEmpty()) continue;
+        region = regions.get(0);
+        regionSet.add(region);
+        firstFailedServer = hrs.getServerName();
+        secondFailedServer = rsts.get((i + 1) % NUM_RS).getRegionServer().getServerName();
+        break;
+      }
+
+      slm.markRegionsRecovering(firstFailedServer, regionSet);
+      slm.markRegionsRecovering(secondFailedServer, regionSet);
+
+      List<String> recoveringRegions = ZKUtil.listChildrenNoWatch(zkw,
+          ZKUtil.joinZNode(zkw.recoveringRegionsZNode, region.getEncodedName()));
+
+      assertEquals(recoveringRegions.size(), 2);
+
+      // wait for splitLogWorker to mark them up because there is no WAL files recorded in ZK
+      final HRegionServer tmphrs = hrs;
+      TEST_UTIL.waitFor(60000, 1000, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (tmphrs.getRecoveringRegions().size() == 0);
+        }
+      });
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testReplayCmd() throws Exception {
+    LOG.info("testReplayCmd");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+    final int NUM_REGIONS_TO_CREATE = 40;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      List<HRegionInfo> regions = null;
+      HRegionServer hrs = null;
+      for (int i = 0; i < NUM_RS; i++) {
+        boolean isCarryingMeta = false;
+        hrs = rsts.get(i).getRegionServer();
+        regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+        for (HRegionInfo region : regions) {
+          if (region.isMetaRegion()) {
+            isCarryingMeta = true;
+            break;
+          }
+        }
+        if (isCarryingMeta) {
+          continue;
+        }
+        if (regions.size() > 0) break;
+      }
+
+      this.prepareData(ht, Bytes.toBytes("family"), Bytes.toBytes("c1"));
+      String originalCheckSum = TEST_UTIL.checksumRows(ht);
+
+      // abort RA and trigger replay
+      abortRSAndWaitForRecovery(hrs, zkw, NUM_REGIONS_TO_CREATE);
+
+      assertEquals("Data should remain after reopening of regions", originalCheckSum,
+          TEST_UTIL.checksumRows(ht));
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testLogReplayForDisablingTable() throws Exception {
+    LOG.info("testLogReplayForDisablingTable");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_LOG_LINES = 1000;
+
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table disablingHT = installTable(zkw, "disableTable", "family", NUM_REGIONS_TO_CREATE);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE, NUM_REGIONS_TO_CREATE);
+    try {
+      // turn off load balancing to prevent regions from moving around otherwise
+      // they will consume recovered.edits
+      master.balanceSwitch(false);
+
+      List<HRegionInfo> regions = null;
+      HRegionServer hrs = null;
+      boolean hasRegionsForBothTables = false;
+      String tableName = null;
+      for (int i = 0; i < NUM_RS; i++) {
+        tableName = null;
+        hasRegionsForBothTables = false;
+        boolean isCarryingSystem = false;
+        hrs = rsts.get(i).getRegionServer();
+        regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+        for (HRegionInfo region : regions) {
+          if (region.getTable().isSystemTable()) {
+            isCarryingSystem = true;
+            break;
+          }
+          if (tableName != null &&
+              !tableName.equalsIgnoreCase(region.getTable().getNameAsString())) {
+            // make sure that we find a RS has online regions for both "table" and "disableTable"
+            hasRegionsForBothTables = true;
+            break;
+          } else if (tableName == null) {
+            tableName = region.getTable().getNameAsString();
+          }
+        }
+        if (isCarryingSystem) {
+          continue;
+        }
+        if (hasRegionsForBothTables) {
+          break;
+        }
+      }
+
+      // make sure we found a good RS
+      Assert.assertTrue(hasRegionsForBothTables);
+
+      LOG.info("#regions = " + regions.size());
+      Iterator<HRegionInfo> it = regions.iterator();
+      while (it.hasNext()) {
+        HRegionInfo region = it.next();
+        if (region.isMetaTable()) {
+          it.remove();
+        }
+      }
+      makeWAL(hrs, regions, "disableTable", "family", NUM_LOG_LINES, 100, false);
+      makeWAL(hrs, regions, "table", "family", NUM_LOG_LINES, 100);
+
+      LOG.info("Disabling table\n");
+      TEST_UTIL.getHBaseAdmin().disableTable(TableName.valueOf("disableTable"));
+      TEST_UTIL.waitTableDisabled(TableName.valueOf("disableTable").getName());
+
+      // abort RS
+      LOG.info("Aborting region server: " + hrs.getServerName());
+      hrs.abort("testing");
+
+      // wait for abort completes
+      TEST_UTIL.waitFor(120000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (cluster.getLiveRegionServerThreads().size() <= (NUM_RS - 1));
+        }
+      });
+
+      // wait for regions come online
+      TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (HBaseTestingUtility.getAllOnlineRegions(cluster).size()
+              >= (NUM_REGIONS_TO_CREATE + 1));
+        }
+      });
+
+      // wait for all regions are fully recovered
+      TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          List<String> recoveringRegions = zkw.getRecoverableZooKeeper().getChildren(
+              zkw.recoveringRegionsZNode, false);
+          ServerManager serverManager = master.getServerManager();
+          return (!serverManager.areDeadServersInProgress() &&
+              recoveringRegions != null && recoveringRegions.size() == 0);
+        }
+      });
+
+      int count = 0;
+      FileSystem fs = master.getMasterFileSystem().getFileSystem();
+      Path rootdir = FSUtils.getRootDir(conf);
+      Path tdir = FSUtils.getTableDir(rootdir, TableName.valueOf("disableTable"));
+      for (HRegionInfo hri : regions) {
+        Path editsdir =
+            WALSplitter.getRegionDirRecoveredEditsDir(
+                HRegion.getRegionDir(tdir, hri.getEncodedName()));
+        LOG.debug("checking edits dir " + editsdir);
+        if(!fs.exists(editsdir)) continue;
+        FileStatus[] files = fs.listStatus(editsdir, new PathFilter() {
+          @Override
+          public boolean accept(Path p) {
+            if (WALSplitter.isSequenceIdFile(p)) {
+              return false;
+            }
+            return true;
+          }
+        });
+        if(files != null) {
+          for(FileStatus file : files) {
+            int c = countWAL(file.getPath(), fs, conf);
+            count += c;
+            LOG.info(c + " edits in " + file.getPath());
+          }
+        }
+      }
+
+      LOG.info("Verify edits in recovered.edits files");
+      assertEquals(NUM_LOG_LINES, count);
+      LOG.info("Verify replayed edits");
+      assertEquals(NUM_LOG_LINES, TEST_UTIL.countRows(ht));
+
+      // clean up
+      for (HRegionInfo hri : regions) {
+        Path editsdir =
+            WALSplitter.getRegionDirRecoveredEditsDir(
+                HRegion.getRegionDir(tdir, hri.getEncodedName()));
+        fs.delete(editsdir, true);
+      }
+      disablingHT.close();
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testDisallowWritesInRecovering() throws Exception {
+    LOG.info("testDisallowWritesInRecovering");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    conf.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 3);
+    conf.setBoolean(HConstants.DISALLOW_WRITES_IN_RECOVERING, true);
+    startCluster(NUM_RS);
+    final int NUM_REGIONS_TO_CREATE = 40;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      final SplitLogManager slm = master.getMasterFileSystem().splitLogManager;
+
+      Set<HRegionInfo> regionSet = new HashSet<HRegionInfo>();
+      HRegionInfo region = null;
+      HRegionServer hrs = null;
+      HRegionServer dstRS = null;
+      for (int i = 0; i < NUM_RS; i++) {
+        hrs = rsts.get(i).getRegionServer();
+        List<HRegionInfo> regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+        if (regions.isEmpty()) continue;
+        region = regions.get(0);
+        regionSet.add(region);
+        dstRS = rsts.get((i+1) % NUM_RS).getRegionServer();
+        break;
+      }
+
+      slm.markRegionsRecovering(hrs.getServerName(), regionSet);
+      // move region in order for the region opened in recovering state
+      final HRegionInfo hri = region;
+      final HRegionServer tmpRS = dstRS;
+      TEST_UTIL.getHBaseAdmin().move(region.getEncodedNameAsBytes(),
+          Bytes.toBytes(dstRS.getServerName().getServerName()));
+      // wait for region move completes
+      final RegionStates regionStates =
+          TEST_UTIL.getHBaseCluster().getMaster().getAssignmentManager().getRegionStates();
+      TEST_UTIL.waitFor(45000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          ServerName sn = regionStates.getRegionServerOfRegion(hri);
+          return (sn != null && sn.equals(tmpRS.getServerName()));
+        }
+      });
+
+      try {
+        byte[] key = region.getStartKey();
+        if (key == null || key.length == 0) {
+          key = new byte[] { 0, 0, 0, 0, 1 };
+        }
+        Put put = new Put(key);
+        put.addColumn(Bytes.toBytes("family"), Bytes.toBytes("c1"), new byte[]{'b'});
+        ht.put(put);
+      } catch (IOException ioe) {
+        Assert.assertTrue(ioe instanceof RetriesExhaustedWithDetailsException);
+        RetriesExhaustedWithDetailsException re = (RetriesExhaustedWithDetailsException) ioe;
+        boolean foundRegionInRecoveryException = false;
+        for (Throwable t : re.getCauses()) {
+          if (t instanceof RegionInRecoveryException) {
+            foundRegionInRecoveryException = true;
+            break;
+          }
+        }
+        Assert.assertTrue(
+            "No RegionInRecoveryException. Following exceptions returned=" + re.getCauses(),
+            foundRegionInRecoveryException);
+      }
+    } finally {
+      if (ht != null) ht.close();
+      if (ht != null) zkw.close();
+    }
+  }
+
+  /**
+   * The original intention of this test was to force an abort of a region
+   * server and to make sure that the failure path in the region servers is
+   * properly evaluated. But it is difficult to ensure that the region server
+   * doesn't finish the log splitting before it aborts. Also now, there is
+   * this code path where the master will preempt the region server when master
+   * detects that the region server has aborted.
+   * @throws Exception
+   */
+  @Ignore ("Disabled because flakey") @Test (timeout=300000)
+  public void testWorkerAbort() throws Exception {
+    LOG.info("testWorkerAbort");
+    startCluster(3);
+    final int NUM_LOG_LINES = 10000;
+    final SplitLogManager slm = master.getMasterFileSystem().splitLogManager;
+    FileSystem fs = master.getMasterFileSystem().getFileSystem();
+
+    final List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    HRegionServer hrs = findRSToKill(false, "table");
+    Path rootdir = FSUtils.getRootDir(conf);
+    final Path logDir = new Path(rootdir,
+        DefaultWALProvider.getWALDirectoryName(hrs.getServerName().toString()));
+
+    Table t = installTable(new ZooKeeperWatcher(conf, "table-creation", null),
+        "table", "family", 40);
+    try {
+      makeWAL(hrs, ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices()),
+          "table", "family", NUM_LOG_LINES, 100);
+
+      new Thread() {
+        @Override
+        public void run() {
+          waitForCounter(tot_wkr_task_acquired, 0, 1, 1000);
+          for (RegionServerThread rst : rsts) {
+            rst.getRegionServer().abort("testing");
+            break;
+          }
+        }
+      }.start();
+      // slm.splitLogDistributed(logDir);
+      FileStatus[] logfiles = fs.listStatus(logDir);
+      TaskBatch batch = new TaskBatch();
+      slm.enqueueSplitTask(logfiles[0].getPath().toString(), batch);
+      //waitForCounter but for one of the 2 counters
+      long curt = System.currentTimeMillis();
+      long waitTime = 80000;
+      long endt = curt + waitTime;
+      while (curt < endt) {
+        if ((tot_wkr_task_resigned.get() + tot_wkr_task_err.get() +
+            tot_wkr_final_transition_failed.get() + tot_wkr_task_done.get() +
+            tot_wkr_preempt_task.get()) == 0) {
+          Thread.yield();
+          curt = System.currentTimeMillis();
+        } else {
+          assertTrue(1 <= (tot_wkr_task_resigned.get() + tot_wkr_task_err.get() +
+              tot_wkr_final_transition_failed.get() + tot_wkr_task_done.get() +
+              tot_wkr_preempt_task.get()));
+          return;
+        }
+      }
+      fail("none of the following counters went up in " + waitTime +
+          " milliseconds - " +
+          "tot_wkr_task_resigned, tot_wkr_task_err, " +
+          "tot_wkr_final_transition_failed, tot_wkr_task_done, " +
+          "tot_wkr_preempt_task");
+    } finally {
+      if (t != null) t.close();
+    }
+  }
+
+  @Test (timeout=300000)
+  public void testThreeRSAbort() throws Exception {
+    LOG.info("testThreeRSAbort");
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_ROWS_PER_REGION = 100;
+
+    startCluster(NUM_RS); // NUM_RS=6.
+
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf,
+        "distributed log splitting test", null);
+
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      populateDataInTable(NUM_ROWS_PER_REGION, "family");
+
+
+      List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+      assertEquals(NUM_RS, rsts.size());
+      rsts.get(0).getRegionServer().abort("testing");
+      rsts.get(1).getRegionServer().abort("testing");
+      rsts.get(2).getRegionServer().abort("testing");
+
+      long start = EnvironmentEdgeManager.currentTime();
+      while (cluster.getLiveRegionServerThreads().size() > (NUM_RS - 3)) {
+        if (EnvironmentEdgeManager.currentTime() - start > 60000) {
+          assertTrue(false);
+        }
+        Thread.sleep(200);
+      }
+
+      start = EnvironmentEdgeManager.currentTime();
+      while (HBaseTestingUtility.getAllOnlineRegions(cluster).size()
+          < (NUM_REGIONS_TO_CREATE + 1)) {
+        if (EnvironmentEdgeManager.currentTime() - start > 60000) {
+          assertTrue("Timedout", false);
+        }
+        Thread.sleep(200);
+      }
+
+      // wait for all regions are fully recovered
+      TEST_UTIL.waitFor(180000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          List<String> recoveringRegions = zkw.getRecoverableZooKeeper().getChildren(
+              zkw.recoveringRegionsZNode, false);
+          return (recoveringRegions != null && recoveringRegions.size() == 0);
+        }
+      });
+
+      assertEquals(NUM_REGIONS_TO_CREATE * NUM_ROWS_PER_REGION,
+          TEST_UTIL.countRows(ht));
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+
+
+  @Test(timeout=30000)
+  public void testDelayedDeleteOnFailure() throws Exception {
+    LOG.info("testDelayedDeleteOnFailure");
+    startCluster(1);
+    final SplitLogManager slm = master.getMasterFileSystem().splitLogManager;
+    final FileSystem fs = master.getMasterFileSystem().getFileSystem();
+    final Path logDir = new Path(FSUtils.getRootDir(conf), "x");
+    fs.mkdirs(logDir);
+    ExecutorService executor = null;
+    try {
+      final Path corruptedLogFile = new Path(logDir, "x");
+      FSDataOutputStream out;
+      out = fs.create(corruptedLogFile);
+      out.write(0);
+      out.write(Bytes.toBytes("corrupted bytes"));
+      out.close();
+      ZKSplitLogManagerCoordination coordination =
+          (ZKSplitLogManagerCoordination) ((BaseCoordinatedStateManager) master
+              .getCoordinatedStateManager()).getSplitLogManagerCoordination();
+      coordination.setIgnoreDeleteForTesting(true);
+      executor = Executors.newSingleThreadExecutor();
+      Runnable runnable = new Runnable() {
+        @Override
+        public void run() {
+          try {
+            // since the logDir is a fake, corrupted one, so the split log worker
+            // will finish it quickly with error, and this call will fail and throw
+            // an IOException.
+            slm.splitLogDistributed(logDir);
+          } catch (IOException ioe) {
+            try {
+              assertTrue(fs.exists(corruptedLogFile));
+              // this call will block waiting for the task to be removed from the
+              // tasks map which is not going to happen since ignoreZKDeleteForTesting
+              // is set to true, until it is interrupted.
+              slm.splitLogDistributed(logDir);
+            } catch (IOException e) {
+              assertTrue(Thread.currentThread().isInterrupted());
+              return;
+            }
+            fail("did not get the expected IOException from the 2nd call");
+          }
+          fail("did not get the expected IOException from the 1st call");
+        }
+      };
+      Future<?> result = executor.submit(runnable);
+      try {
+        result.get(2000, TimeUnit.MILLISECONDS);
+      } catch (TimeoutException te) {
+        // it is ok, expected.
+      }
+      waitForCounter(tot_mgr_wait_for_zk_delete, 0, 1, 10000);
+      executor.shutdownNow();
+      executor = null;
+
+      // make sure the runnable is finished with no exception thrown.
+      result.get();
+    } finally {
+      if (executor != null) {
+        // interrupt the thread in case the test fails in the middle.
+        // it has no effect if the thread is already terminated.
+        executor.shutdownNow();
+      }
+      fs.delete(logDir, true);
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testMetaRecoveryInZK() throws Exception {
+    LOG.info("testMetaRecoveryInZK");
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+
+    // only testing meta recovery in ZK operation
+    HRegionServer hrs = findRSToKill(true, null);
+    List<HRegionInfo> regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+
+    LOG.info("#regions = " + regions.size());
+    Set<HRegionInfo> tmpRegions = new HashSet<HRegionInfo>();
+    tmpRegions.add(HRegionInfo.FIRST_META_REGIONINFO);
+    master.getMasterFileSystem().prepareLogReplay(hrs.getServerName(), tmpRegions);
+    Set<HRegionInfo> userRegionSet = new HashSet<HRegionInfo>();
+    userRegionSet.addAll(regions);
+    master.getMasterFileSystem().prepareLogReplay(hrs.getServerName(), userRegionSet);
+    boolean isMetaRegionInRecovery = false;
+    List<String> recoveringRegions =
+        zkw.getRecoverableZooKeeper().getChildren(zkw.recoveringRegionsZNode, false);
+    for (String curEncodedRegionName : recoveringRegions) {
+      if (curEncodedRegionName.equals(HRegionInfo.FIRST_META_REGIONINFO.getEncodedName())) {
+        isMetaRegionInRecovery = true;
+        break;
+      }
+    }
+    assertTrue(isMetaRegionInRecovery);
+
+    master.getMasterFileSystem().splitMetaLog(hrs.getServerName());
+
+    isMetaRegionInRecovery = false;
+    recoveringRegions =
+        zkw.getRecoverableZooKeeper().getChildren(zkw.recoveringRegionsZNode, false);
+    for (String curEncodedRegionName : recoveringRegions) {
+      if (curEncodedRegionName.equals(HRegionInfo.FIRST_META_REGIONINFO.getEncodedName())) {
+        isMetaRegionInRecovery = true;
+        break;
+      }
+    }
+    // meta region should be recovered
+    assertFalse(isMetaRegionInRecovery);
+    zkw.close();
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testSameVersionUpdatesRecovery() throws Exception {
+    LOG.info("testSameVersionUpdatesRecovery");
+    conf.setLong("hbase.regionserver.hlog.blocksize", 15 * 1024);
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    startCluster(NUM_RS);
+    final AtomicLong sequenceId = new AtomicLong(100);
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_LOG_LINES = 1000;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      List<HRegionInfo> regions = null;
+      HRegionServer hrs = null;
+      for (int i = 0; i < NUM_RS; i++) {
+        boolean isCarryingMeta = false;
+        hrs = rsts.get(i).getRegionServer();
+        regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+        for (HRegionInfo region : regions) {
+          if (region.isMetaRegion()) {
+            isCarryingMeta = true;
+            break;
+          }
+        }
+        if (isCarryingMeta) {
+          continue;
+        }
+        break;
+      }
+
+      LOG.info("#regions = " + regions.size());
+      Iterator<HRegionInfo> it = regions.iterator();
+      while (it.hasNext()) {
+        HRegionInfo region = it.next();
+        if (region.isMetaTable()
+            || region.getEncodedName().equals(
+            HRegionInfo.FIRST_META_REGIONINFO.getEncodedName())) {
+          it.remove();
+        }
+      }
+      if (regions.size() == 0) return;
+      HRegionInfo curRegionInfo = regions.get(0);
+      byte[] startRow = curRegionInfo.getStartKey();
+      if (startRow == null || startRow.length == 0) {
+        startRow = new byte[] { 0, 0, 0, 0, 1 };
+      }
+      byte[] row = Bytes.incrementBytes(startRow, 1);
+      // use last 5 bytes because HBaseTestingUtility.createMultiRegions use 5 bytes key
+      row = Arrays.copyOfRange(row, 3, 8);
+      long value = 0;
+      TableName tableName = TableName.valueOf("table");
+      byte[] family = Bytes.toBytes("family");
+      byte[] qualifier = Bytes.toBytes("c1");
+      long timeStamp = System.currentTimeMillis();
+      HTableDescriptor htd = new HTableDescriptor(tableName);
+      htd.addFamily(new HColumnDescriptor(family));
+      final WAL wal = hrs.getWAL(curRegionInfo);
+      for (int i = 0; i < NUM_LOG_LINES; i += 1) {
+        WALEdit e = new WALEdit();
+        value++;
+        e.add(new KeyValue(row, family, qualifier, timeStamp, Bytes.toBytes(value)));
+        wal.append(htd, curRegionInfo,
+            new HLogKey(curRegionInfo.getEncodedNameAsBytes(), tableName, System.currentTimeMillis()),
+            e, true);
+      }
+      wal.sync();
+      wal.shutdown();
+
+      // wait for abort completes
+      this.abortRSAndWaitForRecovery(hrs, zkw, NUM_REGIONS_TO_CREATE);
+
+      // verify we got the last value
+      LOG.info("Verification Starts...");
+      Get g = new Get(row);
+      Result r = ht.get(g);
+      long theStoredVal = Bytes.toLong(r.getValue(family, qualifier));
+      assertEquals(value, theStoredVal);
+
+      // after flush
+      LOG.info("Verification after flush...");
+      TEST_UTIL.getHBaseAdmin().flush(tableName);
+      r = ht.get(g);
+      theStoredVal = Bytes.toLong(r.getValue(family, qualifier));
+      assertEquals(value, theStoredVal);
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  @Ignore("DLR is broken by HBASE-12751") @Test(timeout = 300000)
+  public void testSameVersionUpdatesRecoveryWithCompaction() throws Exception {
+    LOG.info("testSameVersionUpdatesRecoveryWithWrites");
+    conf.setLong("hbase.regionserver.hlog.blocksize", 15 * 1024);
+    conf.setBoolean(HConstants.DISTRIBUTED_LOG_REPLAY_KEY, true);
+    conf.setInt(HConstants.HREGION_MEMSTORE_FLUSH_SIZE, 30 * 1024);
+    conf.setInt("hbase.hstore.compactionThreshold", 3);
+    startCluster(NUM_RS);
+    final AtomicLong sequenceId = new AtomicLong(100);
+    final int NUM_REGIONS_TO_CREATE = 40;
+    final int NUM_LOG_LINES = 2000;
+    // turn off load balancing to prevent regions from moving around otherwise
+    // they will consume recovered.edits
+    master.balanceSwitch(false);
+
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", NUM_REGIONS_TO_CREATE);
+    try {
+      List<HRegionInfo> regions = null;
+      HRegionServer hrs = null;
+      for (int i = 0; i < NUM_RS; i++) {
+        boolean isCarryingMeta = false;
+        hrs = rsts.get(i).getRegionServer();
+        regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+        for (HRegionInfo region : regions) {
+          if (region.isMetaRegion()) {
+            isCarryingMeta = true;
+            break;
+          }
+        }
+        if (isCarryingMeta) {
+          continue;
+        }
+        break;
+      }
+
+      LOG.info("#regions = " + regions.size());
+      Iterator<HRegionInfo> it = regions.iterator();
+      while (it.hasNext()) {
+        HRegionInfo region = it.next();
+        if (region.isMetaTable()
+            || region.getEncodedName().equals(HRegionInfo.FIRST_META_REGIONINFO.getEncodedName())) {
+          it.remove();
+        }
+      }
+      if (regions.size() == 0) return;
+      HRegionInfo curRegionInfo = regions.get(0);
+      byte[] startRow = curRegionInfo.getStartKey();
+      if (startRow == null || startRow.length == 0) {
+        startRow = new byte[] { 0, 0, 0, 0, 1 };
+      }
+      byte[] row = Bytes.incrementBytes(startRow, 1);
+      // use last 5 bytes because HBaseTestingUtility.createMultiRegions use 5 bytes key
+      row = Arrays.copyOfRange(row, 3, 8);
+      long value = 0;
+      final TableName tableName = TableName.valueOf("table");
+      byte[] family = Bytes.toBytes("family");
+      byte[] qualifier = Bytes.toBytes("c1");
+      long timeStamp = System.currentTimeMillis();
+      HTableDescriptor htd = new HTableDescriptor(tableName);
+      htd.addFamily(new HColumnDescriptor(family));
+      final WAL wal = hrs.getWAL(curRegionInfo);
+      for (int i = 0; i < NUM_LOG_LINES; i += 1) {
+        WALEdit e = new WALEdit();
+        value++;
+        e.add(new KeyValue(row, family, qualifier, timeStamp, Bytes.toBytes(value)));
+        wal.append(htd, curRegionInfo, new HLogKey(curRegionInfo.getEncodedNameAsBytes(),
+            tableName, System.currentTimeMillis()), e, true);
+      }
+      wal.sync();
+      wal.shutdown();
+
+      // wait for abort completes
+      this.abortRSAndWaitForRecovery(hrs, zkw, NUM_REGIONS_TO_CREATE);
+
+      // verify we got the last value
+      LOG.info("Verification Starts...");
+      Get g = new Get(row);
+      Result r = ht.get(g);
+      long theStoredVal = Bytes.toLong(r.getValue(family, qualifier));
+      assertEquals(value, theStoredVal);
+
+      // after flush & compaction
+      LOG.info("Verification after flush...");
+      TEST_UTIL.getHBaseAdmin().flush(tableName);
+      TEST_UTIL.getHBaseAdmin().compact(tableName);
+
+      // wait for compaction completes
+      TEST_UTIL.waitFor(30000, 200, new Waiter.Predicate<Exception>() {
+        @Override
+        public boolean evaluate() throws Exception {
+          return (TEST_UTIL.getHBaseAdmin().getCompactionState(tableName) == CompactionState.NONE);
+        }
+      });
+
+      r = ht.get(g);
+      theStoredVal = Bytes.toLong(r.getValue(family, qualifier));
+      assertEquals(value, theStoredVal);
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  @Test(timeout = 300000)
+  public void testReadWriteSeqIdFiles() throws Exception {
+    LOG.info("testReadWriteSeqIdFiles");
+    startCluster(2);
+    final ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "table-creation", null);
+    Table ht = installTable(zkw, "table", "family", 10);
+    try {
+      FileSystem fs = master.getMasterFileSystem().getFileSystem();
+      Path tableDir = FSUtils.getTableDir(FSUtils.getRootDir(conf), TableName.valueOf("table"));
+      List<Path> regionDirs = FSUtils.getRegionDirs(fs, tableDir);
+      long newSeqId = WALSplitter.writeRegionSequenceIdFile(fs, regionDirs.get(0), 1L, 1000L);
+      WALSplitter.writeRegionSequenceIdFile(fs, regionDirs.get(0) , 1L, 1000L);
+      assertEquals(newSeqId + 2000,
+          WALSplitter.writeRegionSequenceIdFile(fs, regionDirs.get(0), 3L, 1000L));
+
+      Path editsdir = WALSplitter.getRegionDirRecoveredEditsDir(regionDirs.get(0));
+      FileStatus[] files = FSUtils.listStatus(fs, editsdir, new PathFilter() {
+        @Override
+        public boolean accept(Path p) {
+          return WALSplitter.isSequenceIdFile(p);
+        }
+      });
+      // only one seqid file should exist
+      assertEquals(1, files.length);
+
+      // verify all seqId files aren't treated as recovered.edits files
+      NavigableSet<Path> recoveredEdits =
+          WALSplitter.getSplitEditFilesSorted(fs, regionDirs.get(0));
+      assertEquals(0, recoveredEdits.size());
+    } finally {
+      if (ht != null) ht.close();
+      if (zkw != null) zkw.close();
+    }
+  }
+
+  Table installTable(ZooKeeperWatcher zkw, String tname, String fname, int nrs) throws Exception {
+    return installTable(zkw, tname, fname, nrs, 0);
+  }
+
+  Table installTable(ZooKeeperWatcher zkw, String tname, String fname, int nrs,
+      int existingRegions) throws Exception {
+    // Create a table with regions
+    TableName table = TableName.valueOf(tname);
+    byte [] family = Bytes.toBytes(fname);
+    LOG.info("Creating table with " + nrs + " regions");
+    Table ht = TEST_UTIL.createMultiRegionTable(table, family, nrs);
+    int numRegions = -1;
+    try (RegionLocator r = TEST_UTIL.getConnection().getRegionLocator(table)) {
+      numRegions = r.getStartKeys().length;
+    }
+    assertEquals(nrs, numRegions);
+    LOG.info("Waiting for no more RIT\n");
+    blockUntilNoRIT(zkw, master);
+    // disable-enable cycle to get rid of table's dead regions left behind
+    // by createMultiRegions
+    LOG.debug("Disabling table\n");
+    TEST_UTIL.getHBaseAdmin().disableTable(table);
+    LOG.debug("Waiting for no more RIT\n");
+    blockUntilNoRIT(zkw, master);
+    NavigableSet<String> regions = HBaseTestingUtility.getAllOnlineRegions(cluster);
+    LOG.debug("Verifying only catalog and namespace regions are assigned\n");
+    if (regions.size() != 2) {
+      for (String oregion : regions)
+        LOG.debug("Region still online: " + oregion);
+    }
+    assertEquals(2 + existingRegions, regions.size());
+    LOG.debug("Enabling table\n");
+    TEST_UTIL.getHBaseAdmin().enableTable(table);
+    LOG.debug("Waiting for no more RIT\n");
+    blockUntilNoRIT(zkw, master);
+    LOG.debug("Verifying there are " + numRegions + " assigned on cluster\n");
+    regions = HBaseTestingUtility.getAllOnlineRegions(cluster);
+    assertEquals(numRegions + 2 + existingRegions, regions.size());
+    return ht;
+  }
+
+  void populateDataInTable(int nrows, String fname) throws Exception {
+    byte [] family = Bytes.toBytes(fname);
+
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    assertEquals(NUM_RS, rsts.size());
+
+    for (RegionServerThread rst : rsts) {
+      HRegionServer hrs = rst.getRegionServer();
+      List<HRegionInfo> hris = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+      for (HRegionInfo hri : hris) {
+        if (hri.getTable().isSystemTable()) {
+          continue;
+        }
+        LOG.debug("adding data to rs = " + rst.getName() +
+            " region = "+ hri.getRegionNameAsString());
+        Region region = hrs.getOnlineRegion(hri.getRegionName());
+        assertTrue(region != null);
+        putData(region, hri.getStartKey(), nrows, Bytes.toBytes("q"), family);
+      }
+    }
+
+    for (MasterThread mt : cluster.getLiveMasterThreads()) {
+      HRegionServer hrs = mt.getMaster();
+      List<HRegionInfo> hris;
+      try {
+        hris = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+      } catch (ServerNotRunningYetException e) {
+        // It's ok: this master may be a backup. Ignored.
+        continue;
+      }
+      for (HRegionInfo hri : hris) {
+        if (hri.getTable().isSystemTable()) {
+          continue;
+        }
+        LOG.debug("adding data to rs = " + mt.getName() +
+            " region = "+ hri.getRegionNameAsString());
+        Region region = hrs.getOnlineRegion(hri.getRegionName());
+        assertTrue(region != null);
+        putData(region, hri.getStartKey(), nrows, Bytes.toBytes("q"), family);
+      }
+    }
+  }
+
+  public void makeWAL(HRegionServer hrs, List<HRegionInfo> regions, String tname, String fname,
+      int num_edits, int edit_size) throws IOException {
+    makeWAL(hrs, regions, tname, fname, num_edits, edit_size, true);
+  }
+
+  public void makeWAL(HRegionServer hrs, List<HRegionInfo> regions, String tname, String fname,
+      int num_edits, int edit_size, boolean cleanShutdown) throws IOException {
+    TableName fullTName = TableName.valueOf(tname);
+    // remove root and meta region
+    regions.remove(HRegionInfo.FIRST_META_REGIONINFO);
+    // using one sequenceId for edits across all regions is ok.
+    final AtomicLong sequenceId = new AtomicLong(10);
+
+
+    for(Iterator<HRegionInfo> iter = regions.iterator(); iter.hasNext(); ) {
+      HRegionInfo regionInfo = iter.next();
+      if(regionInfo.getTable().isSystemTable()) {
+        iter.remove();
+      }
+    }
+    HTableDescriptor htd = new HTableDescriptor(fullTName);
+    byte[] family = Bytes.toBytes(fname);
+    htd.addFamily(new HColumnDescriptor(family));
+    byte[] value = new byte[edit_size];
+
+    List<HRegionInfo> hris = new ArrayList<HRegionInfo>();
+    for (HRegionInfo region : regions) {
+      if (!region.getTable().getNameAsString().equalsIgnoreCase(tname)) {
+        continue;
+      }
+      hris.add(region);
+    }
+    LOG.info("Creating wal edits across " + hris.size() + " regions.");
+    for (int i = 0; i < edit_size; i++) {
+      value[i] = (byte) ('a' + (i % 26));
+    }
+    int n = hris.size();
+    int[] counts = new int[n];
+    // sync every ~30k to line up with desired wal rolls
+    final int syncEvery = 30 * 1024 / edit_size;
+    if (n > 0) {
+      for (int i = 0; i < num_edits; i += 1) {
+        WALEdit e = new WALEdit();
+        HRegionInfo curRegionInfo = hris.get(i % n);
+        final WAL log = hrs.getWAL(curRegionInfo);
+        byte[] startRow = curRegionInfo.getStartKey();
+        if (startRow == null || startRow.length == 0) {
+          startRow = new byte[] { 0, 0, 0, 0, 1 };
+        }
+        byte[] row = Bytes.incrementBytes(startRow, counts[i % n]);
+        row = Arrays.copyOfRange(row, 3, 8); // use last 5 bytes because
+        // HBaseTestingUtility.createMultiRegions use 5 bytes
+        // key
+        byte[] qualifier = Bytes.toBytes("c" + Integer.toString(i));
+        e.add(new KeyValue(row, family, qualifier, System.currentTimeMillis(), value));
+        log.append(htd, curRegionInfo,
+            new HLogKey(curRegionInfo.getEncodedNameAsBytes(), fullTName,
+                System.currentTimeMillis()), e, true);
+        if (0 == i % syncEvery) {
+          log.sync();
+        }
+        counts[i % n] += 1;
+      }
+    }
+    // done as two passes because the regions might share logs. shutdown is idempotent, but sync
+    // will cause errors if done after.
+    for (HRegionInfo info : hris) {
+      final WAL log = hrs.getWAL(info);
+      log.sync();
+    }
+    if (cleanShutdown) {
+      for (HRegionInfo info : hris) {
+        final WAL log = hrs.getWAL(info);
+        log.shutdown();
+      }
+    }
+    for (int i = 0; i < n; i++) {
+      LOG.info("region " + hris.get(i).getRegionNameAsString() + " has " + counts[i] + " edits");
+    }
+    return;
+  }
+
+  private int countWAL(Path log, FileSystem fs, Configuration conf)
+      throws IOException {
+    int count = 0;
+    WAL.Reader in = WALFactory.createReader(fs, log, conf);
+    try {
+      WAL.Entry e;
+      while ((e = in.next()) != null) {
+        if (!WALEdit.isMetaEditFamily(e.getEdit().getCells().get(0))) {
+          count++;
+        }
+      }
+    } finally {
+      try {
+        in.close();
+      } catch (IOException exception) {
+        LOG.warn("Problem closing wal: " + exception.getMessage());
+        LOG.debug("exception details.", exception);
+      }
+    }
+    return count;
+  }
+
+  private void blockUntilNoRIT(ZooKeeperWatcher zkw, HMaster master) throws Exception {
+    TEST_UTIL.waitUntilNoRegionsInTransition(60000);
+  }
+
+  private void putData(Region region, byte[] startRow, int numRows, byte [] qf,
+      byte [] ...families)
+      throws IOException {
+    for(int i = 0; i < numRows; i++) {
+      Put put = new Put(Bytes.add(startRow, Bytes.toBytes(i)));
+      for(byte [] family : families) {
+        put.addColumn(family, qf, null);
+      }
+      region.put(put);
+    }
+  }
+
+  /**
+   * Load table with puts and deletes with expected values so that we can verify later
+   */
+  private void prepareData(final Table t, final byte[] f, final byte[] column) throws IOException {
+    byte[] k = new byte[3];
+
+    // add puts
+    List<Put> puts = new ArrayList<>();
+    for (byte b1 = 'a'; b1 <= 'z'; b1++) {
+      for (byte b2 = 'a'; b2 <= 'z'; b2++) {
+        for (byte b3 = 'a'; b3 <= 'z'; b3++) {
+          k[0] = b1;
+          k[1] = b2;
+          k[2] = b3;
+          Put put = new Put(k);
+          put.addColumn(f, column, k);
+          puts.add(put);
+        }
+      }
+    }
+    t.put(puts);
+    // add deletes
+    for (byte b3 = 'a'; b3 <= 'z'; b3++) {
+      k[0] = 'a';
+      k[1] = 'a';
+      k[2] = b3;
+      Delete del = new Delete(k);
+      t.delete(del);
+    }
+  }
+
+  private void waitForCounter(AtomicLong ctr, long oldval, long newval,
+      long timems) {
+    long curt = System.currentTimeMillis();
+    long endt = curt + timems;
+    while (curt < endt) {
+      if (ctr.get() == oldval) {
+        Thread.yield();
+        curt = System.currentTimeMillis();
+      } else {
+        assertEquals(newval, ctr.get());
+        return;
+      }
+    }
+    assertTrue(false);
+  }
+
+  private void abortMaster(MiniHBaseCluster cluster) throws InterruptedException {
+    for (MasterThread mt : cluster.getLiveMasterThreads()) {
+      if (mt.getMaster().isActiveMaster()) {
+        mt.getMaster().abort("Aborting for tests", new Exception("Trace info"));
+        mt.join();
+        break;
+      }
+    }
+    LOG.debug("Master is aborted");
+  }
+
+  /**
+   * Find a RS that has regions of a table.
+   * @param hasMetaRegion when true, the returned RS has hbase:meta region as well
+   * @param tableName
+   * @return
+   * @throws Exception
+   */
+  private HRegionServer findRSToKill(boolean hasMetaRegion, String tableName) throws Exception {
+    List<RegionServerThread> rsts = cluster.getLiveRegionServerThreads();
+    List<HRegionInfo> regions = null;
+    HRegionServer hrs = null;
+
+    for (RegionServerThread rst: rsts) {
+      hrs = rst.getRegionServer();
+      while (rst.isAlive() && !hrs.isOnline()) {
+        Thread.sleep(100);
+      }
+      if (!rst.isAlive()) {
+        continue;
+      }
+      boolean isCarryingMeta = false;
+      boolean foundTableRegion = false;
+      regions = ProtobufUtil.getOnlineRegions(hrs.getRSRpcServices());
+      for (HRegionInfo region : regions) {
+        if (region.isMetaRegion()) {
+          isCarryingMeta = true;
+        }
+        if (tableName == null || region.getTable().getNameAsString().equals(tableName)) {
+          foundTableRegion = true;
+        }
+        if (foundTableRegion && (isCarryingMeta || !hasMetaRegion)) {
+          break;
+        }
+      }
+      if (isCarryingMeta && hasMetaRegion) {
+        // clients ask for a RS with META
+        if (!foundTableRegion) {
+          final HRegionServer destRS = hrs;
+          // the RS doesn't have regions of the specified table so we need move one to this RS
+          List<HRegionInfo> tableRegions =
+              TEST_UTIL.getHBaseAdmin().getTableRegions(TableName.valueOf(tableName));
+          final HRegionInfo hri = tableRegions.get(0);
+          TEST_UTIL.getHBaseAdmin().move(hri.getEncodedNameAsBytes(),
+              Bytes.toBytes(destRS.getServerName().getServerName()));
+          // wait for region move completes
+          final RegionStates regionStates =
+              TEST_UTIL.getHBaseCluster().getMaster().getAssignmentManager().getRegionStates();
+          TEST_UTIL.waitFor(45000, 200, new Waiter.Predicate<Exception>() {
+            @Override
+            public boolean evaluate() throws Exception {
+              ServerName sn = regionStates.getRegionServerOfRegion(hri);
+              return (sn != null && sn.equals(destRS.getServerName()));
+            }
+          });
+        }
+        return hrs;
+      } else if (hasMetaRegion || isCarryingMeta) {
+        continue;
+      }
+      if (foundTableRegion) break;
+    }
+
+    return hrs;
+  }
+}
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/hbase/blob/30cec72f/hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/TestStochasticLoadBalancer2.java
----------------------------------------------------------------------
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/TestStochasticLoadBalancer2.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/TestStochasticLoadBalancer2.java
new file mode 100644
index 0000000..395eef2
--- /dev/null
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/TestStochasticLoadBalancer2.java
@@ -0,0 +1,90 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master.balancer;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hbase.testclassification.FlakeyTests;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category({FlakeyTests.class, MediumTests.class})
+public class TestStochasticLoadBalancer2 extends BalancerTestBase {
+  private static final Log LOG = LogFactory.getLog(TestStochasticLoadBalancer2.class);
+
+  @Test (timeout = 800000)
+  public void testRegionReplicasOnMidCluster() {
+    conf.setFloat("hbase.master.balancer.stochastic.maxMovePercent", 1.0f);
+    conf.setLong(StochasticLoadBalancer.MAX_STEPS_KEY, 2000000L);
+    conf.setLong("hbase.master.balancer.stochastic.maxRunningTime", 90 * 1000); // 90 sec
+    conf.setFloat("hbase.master.balancer.stochastic.localityCost", 0);
+    TestStochasticLoadBalancer.loadBalancer.setConf(conf);
+    int numNodes = 200;
+    int numRegions = 40 * 200;
+    int replication = 3; // 3 replicas per region
+    int numRegionsPerServer = 30; //all regions are mostly balanced
+    int numTables = 10;
+    testWithCluster(numNodes, numRegions, numRegionsPerServer, replication, numTables, true, true);
+  }
+
+  @Test (timeout = 800000)
+  public void testRegionReplicasOnLargeCluster() {
+    conf.setFloat("hbase.master.balancer.stochastic.maxMovePercent", 1.0f);
+    conf.setLong(StochasticLoadBalancer.MAX_STEPS_KEY, 2000000L);
+    conf.setLong("hbase.master.balancer.stochastic.maxRunningTime", 90 * 1000); // 90 sec
+    conf.setFloat("hbase.master.balancer.stochastic.localityCost", 0);
+    loadBalancer.setConf(conf);
+    int numNodes = 1000;
+    int numRegions = 20 * numNodes; // 20 * replication regions per RS
+    int numRegionsPerServer = 19; // all servers except one
+    int numTables = 100;
+    int replication = 3;
+    testWithCluster(numNodes, numRegions, numRegionsPerServer, replication, numTables, true, true);
+  }
+
+  @Test (timeout = 800000)
+  public void testRegionReplicasOnMidClusterHighReplication() {
+    conf.setLong(StochasticLoadBalancer.MAX_STEPS_KEY, 4000000L);
+    conf.setLong("hbase.master.balancer.stochastic.maxRunningTime", 120 * 1000); // 120 sec
+    conf.setFloat("hbase.master.balancer.stochastic.localityCost", 0);
+    conf.setFloat("hbase.master.balancer.stochastic.maxMovePercent", 1.0f);
+    loadBalancer.setConf(conf);
+    int numNodes = 80;
+    int numRegions = 6 * numNodes;
+    int replication = 80; // 80 replicas per region, one for each server
+    int numRegionsPerServer = 5;
+    int numTables = 10;
+    testWithCluster(numNodes, numRegions, numRegionsPerServer, replication, numTables, false, true);
+  }
+
+  @Test (timeout = 800000)
+  public void testRegionReplicationOnMidClusterReplicationGreaterThanNumNodes() {
+    conf.setLong(StochasticLoadBalancer.MAX_STEPS_KEY, 2000000L);
+    conf.setLong("hbase.master.balancer.stochastic.maxRunningTime", 120 * 1000); // 120 sec
+    conf.setFloat("hbase.master.balancer.stochastic.localityCost", 0);
+    conf.setFloat("hbase.master.balancer.stochastic.maxMovePercent", 1.0f);
+    loadBalancer.setConf(conf);
+    int numNodes = 40;
+    int numRegions = 6 * 50;
+    int replication = 50; // 50 replicas per region, more than numNodes
+    int numRegionsPerServer = 6;
+    int numTables = 10;
+    testWithCluster(numNodes, numRegions, numRegionsPerServer, replication, numTables, true, false);
+  }
+}
\ No newline at end of file