Java HAUtil.setAllowStandbyReads方法代码示例

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Before
public void setupCluster() throws Exception {
  Configuration conf = new Configuration();
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  HAUtil.setAllowStandbyReads(conf, true);
  
  cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(MiniDFSNNTopology.simpleHATopology())
    .numDataNodes(1)
    .waitSafeMode(false)
    .build();
  cluster.waitActive();
  
  nn0 = cluster.getNameNode(0);
  nn1 = cluster.getNameNode(1);
  fs = HATestUtil.configureFailoverFs(cluster, conf);
  
  cluster.transitionToActive(0);
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Before
public void setupCluster() throws IOException {
  conf = new Configuration();
  conf.setInt(DFSConfigKeys.DFS_HA_LOGROLL_PERIOD_KEY, 1);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  HAUtil.setAllowStandbyReads(conf, true);
  
  MiniDFSNNTopology topology = MiniDFSNNTopology.simpleHATopology();
  
  cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(topology)
    .numDataNodes(0)
    .build();
  cluster.waitActive();

  shutdownClusterAndRemoveSharedEditsDir();
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Before
public void setupCluster() throws Exception {
  Configuration conf = new Configuration();
  conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, BLOCK_SIZE);
  HAUtil.setAllowStandbyReads(conf, true);
  
  cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(MiniDFSNNTopology.simpleHATopology())
    .numDataNodes(1)
    .waitSafeMode(false)
    .build();
  cluster.waitActive();
  
  nn0 = cluster.getNameNode(0);
  nn1 = cluster.getNameNode(1);
  fs = HATestUtil.configureFailoverFs(cluster, conf);
  
  cluster.transitionToActive(0);
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Before
public void setUpCluster() throws Exception {
  conf = new Configuration();
  conf.setInt(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_CHECK_PERIOD_KEY, 1);
  conf.setInt(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_TXNS_KEY, 1);
  conf.setInt(DFSConfigKeys.DFS_NAMENODE_NUM_CHECKPOINTS_RETAINED_KEY, 10);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  HAUtil.setAllowStandbyReads(conf, true);
  
  if (clusterType == TestType.SHARED_DIR_HA) {
    MiniDFSNNTopology topology = MiniQJMHACluster.createDefaultTopology(10000);
    cluster = new MiniDFSCluster.Builder(conf)
      .nnTopology(topology)
      .numDataNodes(0)
      .checkExitOnShutdown(false)
      .build();
  } else {
    Builder builder = new MiniQJMHACluster.Builder(conf);
    builder.getDfsBuilder().numDataNodes(0).checkExitOnShutdown(false);
    miniQjmHaCluster = builder.build();
    cluster = miniQjmHaCluster.getDfsCluster();
  }
  cluster.waitActive();
  
  nn0 = cluster.getNameNode(0);
  nn1 = cluster.getNameNode(1);
  
  cluster.transitionToActive(0);
  fs = HATestUtil.configureFailoverFs(cluster, conf);
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
/**
 * Test that getContentSummary on Standby should should throw standby
 * exception.
 */
@Test(expected = StandbyException.class)
public void testgetContentSummaryOnStandby() throws Exception {
  Configuration nn1conf =cluster.getConfiguration(1);
  // just reset the standby reads to default i.e False on standby.
  HAUtil.setAllowStandbyReads(nn1conf, false);
  cluster.restartNameNode(1);
  cluster.getNameNodeRpc(1).getContentSummary("/");
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Before
public void setUpCluster() throws Exception {
  conf = new Configuration();
  conf.setInt(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_CHECK_PERIOD_KEY, 1);
  conf.setInt(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_TXNS_KEY, 1);
  conf.setInt(DFSConfigKeys.DFS_NAMENODE_NUM_CHECKPOINTS_RETAINED_KEY, 10);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  HAUtil.setAllowStandbyReads(conf, true);
  
  MiniDFSNNTopology topology = new MiniDFSNNTopology()
    .addNameservice(new MiniDFSNNTopology.NSConf("ns1")
      .addNN(new MiniDFSNNTopology.NNConf("nn1").setHttpPort(10001))
      .addNN(new MiniDFSNNTopology.NNConf("nn2").setHttpPort(10002)));
  cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(topology)
    .numDataNodes(0)
    .checkExitOnShutdown(false)
    .build();
  
  cluster.waitActive();
  
  nn0 = cluster.getNameNode(0);
  nn1 = cluster.getNameNode(1);
  
  cluster.transitionToActive(0);
  fs = HATestUtil.configureFailoverFs(cluster, conf);
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
/**
 * Ensure that the backupnode will tail edits from the NN
 * and keep in sync, even while the NN rolls, checkpoints
 * occur, etc.
 */
@Test
public void testBackupNodeTailsEdits() throws Exception {
  Configuration conf = new HdfsConfiguration();
  HAUtil.setAllowStandbyReads(conf, true);
  MiniDFSCluster cluster = null;
  FileSystem fileSys = null;
  BackupNode backup = null;

  try {
    cluster = new MiniDFSCluster.Builder(conf)
                                .numDataNodes(0).build();
    fileSys = cluster.getFileSystem();
    backup = startBackupNode(conf, StartupOption.BACKUP, 1);
    
    BackupImage bnImage = (BackupImage) backup.getFSImage();
    testBNInSync(cluster, backup, 1);
    
    // Force a roll -- BN should roll with NN.
    NameNode nn = cluster.getNameNode();
    NamenodeProtocols nnRpc = nn.getRpcServer();
    nnRpc.rollEditLog();
    assertEquals(bnImage.getEditLog().getCurSegmentTxId(),
        nn.getFSImage().getEditLog().getCurSegmentTxId());
    
    // BN should stay in sync after roll
    testBNInSync(cluster, backup, 2);
    
    long nnImageBefore =
      nn.getFSImage().getStorage().getMostRecentCheckpointTxId();
    // BN checkpoint
    backup.doCheckpoint();
    
    // NN should have received a new image
    long nnImageAfter =
      nn.getFSImage().getStorage().getMostRecentCheckpointTxId();
    
    assertTrue("nn should have received new checkpoint. before: " +
        nnImageBefore + " after: " + nnImageAfter,
        nnImageAfter > nnImageBefore);

    // BN should stay in sync after checkpoint
    testBNInSync(cluster, backup, 3);

    // Stop BN
    StorageDirectory sd = bnImage.getStorage().getStorageDir(0);
    backup.stop();
    backup = null;
    
    // When shutting down the BN, it shouldn't finalize logs that are
    // still open on the NN
    EditLogFile editsLog = FSImageTestUtil.findLatestEditsLog(sd);
    assertEquals(editsLog.getFirstTxId(),
        nn.getFSImage().getEditLog().getCurSegmentTxId());
    assertTrue("Should not have finalized " + editsLog,
        editsLog.isInProgress());
    
    // do some edits
    assertTrue(fileSys.mkdirs(new Path("/edit-while-bn-down")));
    
    // start a new backup node
    backup = startBackupNode(conf, StartupOption.BACKUP, 1);

    testBNInSync(cluster, backup, 4);
    assertNotNull(backup.getNamesystem().getFileInfo("/edit-while-bn-down", false));
  } finally {
    LOG.info("Shutting down...");
    if (backup != null) backup.stop();
    if (fileSys != null) fileSys.close();
    if (cluster != null) cluster.shutdown();
  }
  
  assertStorageDirsMatch(cluster.getNameNode(), backup);
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Test
public void testTailer() throws IOException, InterruptedException,
    ServiceFailedException {
  Configuration conf = new HdfsConfiguration();
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);

  HAUtil.setAllowStandbyReads(conf, true);
  
  MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(MiniDFSNNTopology.simpleHATopology())
    .numDataNodes(0)
    .build();
  cluster.waitActive();
  
  cluster.transitionToActive(0);
  
  NameNode nn1 = cluster.getNameNode(0);
  NameNode nn2 = cluster.getNameNode(1);
  try {
    for (int i = 0; i < DIRS_TO_MAKE / 2; i++) {
      NameNodeAdapter.mkdirs(nn1, getDirPath(i),
          new PermissionStatus("test","test", new FsPermission((short)00755)),
          true);
    }
    
    HATestUtil.waitForStandbyToCatchUp(nn1, nn2);
    
    for (int i = 0; i < DIRS_TO_MAKE / 2; i++) {
      assertTrue(NameNodeAdapter.getFileInfo(nn2,
          getDirPath(i), false).isDir());
    }
    
    for (int i = DIRS_TO_MAKE / 2; i < DIRS_TO_MAKE; i++) {
      NameNodeAdapter.mkdirs(nn1, getDirPath(i),
          new PermissionStatus("test","test", new FsPermission((short)00755)),
          true);
    }
    
    HATestUtil.waitForStandbyToCatchUp(nn1, nn2);
    
    for (int i = DIRS_TO_MAKE / 2; i < DIRS_TO_MAKE; i++) {
      assertTrue(NameNodeAdapter.getFileInfo(nn2,
          getDirPath(i), false).isDir());
    }
  } finally {
    cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Test
public void testStartup() throws Exception {
  Configuration conf = new Configuration();
  HAUtil.setAllowStandbyReads(conf, true);
  MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(MiniDFSNNTopology.simpleHATopology())
    .numDataNodes(0)
    .build();
  try {
    // During HA startup, both nodes should be in
    // standby and we shouldn't have any edits files
    // in any edits directory!
    List<URI> allDirs = Lists.newArrayList();
    allDirs.addAll(cluster.getNameDirs(0));
    allDirs.addAll(cluster.getNameDirs(1));
    allDirs.add(cluster.getSharedEditsDir(0, 1));
    assertNoEditFiles(allDirs);
    
    // Set the first NN to active, make sure it creates edits
    // in its own dirs and the shared dir. The standby
    // should still have no edits!
    cluster.transitionToActive(0);
    
    assertEditFiles(cluster.getNameDirs(0),
        NNStorage.getInProgressEditsFileName(1));
    assertEditFiles(
        Collections.singletonList(cluster.getSharedEditsDir(0, 1)),
        NNStorage.getInProgressEditsFileName(1));
    assertNoEditFiles(cluster.getNameDirs(1));
    
    cluster.getNameNode(0).getRpcServer().mkdirs("/test",
        FsPermission.createImmutable((short)0755), true);

    // Restarting the standby should not finalize any edits files
    // in the shared directory when it starts up!
    cluster.restartNameNode(1);
    
    assertEditFiles(cluster.getNameDirs(0),
        NNStorage.getInProgressEditsFileName(1));
    assertEditFiles(
        Collections.singletonList(cluster.getSharedEditsDir(0, 1)),
        NNStorage.getInProgressEditsFileName(1));
    assertNoEditFiles(cluster.getNameDirs(1));
    
    // Additionally it should not have applied any in-progress logs
    // at start-up -- otherwise, it would have read half-way into
    // the current log segment, and on the next roll, it would have to
    // either replay starting in the middle of the segment (not allowed)
    // or double-replay the edits (incorrect).
    assertNull(NameNodeAdapter.getFileInfo(cluster.getNameNode(1), "/test", true));
    
    cluster.getNameNode(0).getRpcServer().mkdirs("/test2",
        FsPermission.createImmutable((short)0755), true);

    // If we restart NN0, it'll come back as standby, and we can
    // transition NN1 to active and make sure it reads edits correctly at this point.
    cluster.restartNameNode(0);
    cluster.transitionToActive(1);

    // NN1 should have both the edits that came before its restart, and the edits that
    // came after its restart.
    assertNotNull(NameNodeAdapter.getFileInfo(cluster.getNameNode(1), "/test", true));
    assertNotNull(NameNodeAdapter.getFileInfo(cluster.getNameNode(1), "/test2", true));
  } finally {
    cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Test(timeout=60000)
public void testStandbyIsHot() throws Exception {
  Configuration conf = new Configuration();
  // We read from the standby to watch block locations
  HAUtil.setAllowStandbyReads(conf, true);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(MiniDFSNNTopology.simpleHATopology())
    .numDataNodes(3)
    .build();
  try {
    cluster.waitActive();
    cluster.transitionToActive(0);
    
    NameNode nn1 = cluster.getNameNode(0);
    NameNode nn2 = cluster.getNameNode(1);
    
    FileSystem fs = HATestUtil.configureFailoverFs(cluster, conf);
    
    Thread.sleep(1000);
    System.err.println("==================================");
    DFSTestUtil.writeFile(fs, TEST_FILE_PATH, TEST_FILE_DATA);
    // Have to force an edit log roll so that the standby catches up
    nn1.getRpcServer().rollEditLog();
    System.err.println("==================================");

    // Block locations should show up on standby.
    LOG.info("Waiting for block locations to appear on standby node");
    waitForBlockLocations(cluster, nn2, TEST_FILE, 3);

    // Trigger immediate heartbeats and block reports so
    // that the active "trusts" all of the DNs
    cluster.triggerHeartbeats();
    cluster.triggerBlockReports();

    // Change replication
    LOG.info("Changing replication to 1");
    fs.setReplication(TEST_FILE_PATH, (short)1);
    BlockManagerTestUtil.computeAllPendingWork(
        nn1.getNamesystem().getBlockManager());
    waitForBlockLocations(cluster, nn1, TEST_FILE, 1);

    nn1.getRpcServer().rollEditLog();
    
    LOG.info("Waiting for lowered replication to show up on standby");
    waitForBlockLocations(cluster, nn2, TEST_FILE, 1);
    
    // Change back to 3
    LOG.info("Changing replication to 3");
    fs.setReplication(TEST_FILE_PATH, (short)3);
    BlockManagerTestUtil.computeAllPendingWork(
        nn1.getNamesystem().getBlockManager());
    nn1.getRpcServer().rollEditLog();
    
    LOG.info("Waiting for higher replication to show up on standby");
    waitForBlockLocations(cluster, nn2, TEST_FILE, 3);
    
  } finally {
    cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
/**
 * Regression test for HDFS-2795:
 *  - Start an HA cluster with a DN.
 *  - Write several blocks to the FS with replication 1.
 *  - Shutdown the DN
 *  - Wait for the NNs to declare the DN dead. All blocks will be under-replicated.
 *  - Restart the DN.
 * In the bug, the standby node would only very slowly notice the blocks returning
 * to the cluster.
 */
@Test(timeout=60000)
public void testDatanodeRestarts() throws Exception {
  Configuration conf = new Configuration();
  conf.setInt(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 1024);
  // We read from the standby to watch block locations
  HAUtil.setAllowStandbyReads(conf, true);
  conf.setLong(DFSConfigKeys.DFS_NAMENODE_ACCESSTIME_PRECISION_KEY, 0);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(MiniDFSNNTopology.simpleHATopology())
    .numDataNodes(1)
    .build();
  try {
    NameNode nn0 = cluster.getNameNode(0);
    NameNode nn1 = cluster.getNameNode(1);

    cluster.transitionToActive(0);
    
    // Create 5 blocks.
    DFSTestUtil.createFile(cluster.getFileSystem(0), 
        TEST_FILE_PATH, 5*1024, (short)1, 1L);
    
    HATestUtil.waitForStandbyToCatchUp(nn0, nn1);
    
    // Stop the DN.
    DataNode dn = cluster.getDataNodes().get(0);
    String dnName = dn.getDatanodeId().getXferAddr(); 
    DataNodeProperties dnProps = cluster.stopDataNode(0);
    
    // Make sure both NNs register it as dead.
    BlockManagerTestUtil.noticeDeadDatanode(nn0, dnName);
    BlockManagerTestUtil.noticeDeadDatanode(nn1, dnName);
    
    BlockManagerTestUtil.updateState(nn0.getNamesystem().getBlockManager());
    BlockManagerTestUtil.updateState(nn1.getNamesystem().getBlockManager());
    assertEquals(5, nn0.getNamesystem().getUnderReplicatedBlocks());
    
    // The SBN will not have any blocks in its neededReplication queue
    // since the SBN doesn't process replication.
    assertEquals(0, nn1.getNamesystem().getUnderReplicatedBlocks());
    
    LocatedBlocks locs = nn1.getRpcServer().getBlockLocations(
        TEST_FILE, 0, 1);
    assertEquals("Standby should have registered that the block has no replicas",
        0, locs.get(0).getLocations().length);
    
    cluster.restartDataNode(dnProps);
    // Wait for both NNs to re-register the DN.
    cluster.waitActive(0);
    cluster.waitActive(1);
    
    BlockManagerTestUtil.updateState(nn0.getNamesystem().getBlockManager());
    BlockManagerTestUtil.updateState(nn1.getNamesystem().getBlockManager());
    assertEquals(0, nn0.getNamesystem().getUnderReplicatedBlocks());
    assertEquals(0, nn1.getNamesystem().getUnderReplicatedBlocks());
    
    locs = nn1.getRpcServer().getBlockLocations(
        TEST_FILE, 0, 1);
    assertEquals("Standby should have registered that the block has replicas again",
        1, locs.get(0).getLocations().length);
  } finally {
    cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Test(timeout=60000)
public void testInvalidateBlock() throws Exception {
  Configuration conf = new Configuration();
  HAUtil.setAllowStandbyReads(conf, true);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
      .nnTopology(MiniDFSNNTopology.simpleHATopology())
      .numDataNodes(3)
      .build();
  try {
    cluster.waitActive();
    cluster.transitionToActive(0);

    NameNode nn1 = cluster.getNameNode(0);
    NameNode nn2 = cluster.getNameNode(1);

    FileSystem fs = HATestUtil.configureFailoverFs(cluster, conf);

    Thread.sleep(1000);
    LOG.info("==================================");
    DFSTestUtil.writeFile(fs, TEST_FILE_PATH, TEST_FILE_DATA);
    // Have to force an edit log roll so that the standby catches up
    nn1.getRpcServer().rollEditLog();
    LOG.info("==================================");

    // delete the file
    fs.delete(TEST_FILE_PATH, false);
    BlockManagerTestUtil.computeAllPendingWork(
        nn1.getNamesystem().getBlockManager());

    nn1.getRpcServer().rollEditLog();

    // standby nn doesn't need to invalidate blocks.
    assertEquals(0,
        nn2.getNamesystem().getBlockManager().getPendingDeletionBlocksCount());

    cluster.triggerHeartbeats();
    cluster.triggerBlockReports();

    // standby nn doesn't need to invalidate blocks.
    assertEquals(0,
        nn2.getNamesystem().getBlockManager().getPendingDeletionBlocksCount());

  } finally {
    cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
/**
 * Use NameNode INTIALIZESHAREDEDITS to initialize the shared edits. i.e. copy
 * the edits log segments to new bkjm shared edits.
 * 
 * @throws Exception
 */
@Test
public void testInitializeBKSharedEdits() throws Exception {
  MiniDFSCluster cluster = null;
  try {
    Configuration conf = new Configuration();
    HAUtil.setAllowStandbyReads(conf, true);
    conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);

    MiniDFSNNTopology topology = MiniDFSNNTopology.simpleHATopology();
    cluster = new MiniDFSCluster.Builder(conf).nnTopology(topology)
        .numDataNodes(0).build();
    cluster.waitActive();
    // Shutdown and clear the current filebased shared dir.
    cluster.shutdownNameNodes();
    File shareddir = new File(cluster.getSharedEditsDir(0, 1));
    assertTrue("Initial Shared edits dir not fully deleted",
        FileUtil.fullyDelete(shareddir));

    // Check namenodes should not start without shared dir.
    assertCanNotStartNamenode(cluster, 0);
    assertCanNotStartNamenode(cluster, 1);

    // Configure bkjm as new shared edits dir in both namenodes
    Configuration nn1Conf = cluster.getConfiguration(0);
    Configuration nn2Conf = cluster.getConfiguration(1);
    nn1Conf.set(DFSConfigKeys.DFS_NAMENODE_SHARED_EDITS_DIR_KEY, BKJMUtil
        .createJournalURI("/initializeSharedEdits").toString());
    nn2Conf.set(DFSConfigKeys.DFS_NAMENODE_SHARED_EDITS_DIR_KEY, BKJMUtil
        .createJournalURI("/initializeSharedEdits").toString());
    BKJMUtil.addJournalManagerDefinition(nn1Conf);
    BKJMUtil.addJournalManagerDefinition(nn2Conf);

    // Initialize the BKJM shared edits.
    assertFalse(NameNode.initializeSharedEdits(nn1Conf));

    // NameNode should be able to start and should be in sync with BKJM as
    // shared dir
    assertCanStartHANameNodes(cluster, conf, "/testBKJMInitialize");
  } finally {
    if (cluster != null) {
      cluster.shutdown();
    }
  }
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
@Test
public void testTailer() throws IOException, InterruptedException,
    ServiceFailedException {
  Configuration conf = new HdfsConfiguration();
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_ALL_NAMESNODES_RETRY_KEY, 100);

  HAUtil.setAllowStandbyReads(conf, true);
  
  MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(MiniDFSNNTopology.simpleHATopology())
    .numDataNodes(0)
    .build();
  cluster.waitActive();
  
  cluster.transitionToActive(0);
  
  NameNode nn1 = cluster.getNameNode(0);
  NameNode nn2 = cluster.getNameNode(1);
  try {
    for (int i = 0; i < DIRS_TO_MAKE / 2; i++) {
      NameNodeAdapter.mkdirs(nn1, getDirPath(i),
          new PermissionStatus("test","test", new FsPermission((short)00755)),
          true);
    }
    
    HATestUtil.waitForStandbyToCatchUp(nn1, nn2);
    
    for (int i = 0; i < DIRS_TO_MAKE / 2; i++) {
      assertTrue(NameNodeAdapter.getFileInfo(nn2,
          getDirPath(i), false).isDir());
    }
    
    for (int i = DIRS_TO_MAKE / 2; i < DIRS_TO_MAKE; i++) {
      NameNodeAdapter.mkdirs(nn1, getDirPath(i),
          new PermissionStatus("test","test", new FsPermission((short)00755)),
          true);
    }
    
    HATestUtil.waitForStandbyToCatchUp(nn1, nn2);
    
    for (int i = DIRS_TO_MAKE / 2; i < DIRS_TO_MAKE; i++) {
      assertTrue(NameNodeAdapter.getFileInfo(nn2,
          getDirPath(i), false).isDir());
    }
  } finally {
    cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.HAUtil; //导入方法依赖的package包/类
/**
 * Regression test for HDFS-2795:
 *  - Start an HA cluster with a DN.
 *  - Write several blocks to the FS with replication 1.
 *  - Shutdown the DN
 *  - Wait for the NNs to declare the DN dead. All blocks will be under-replicated.
 *  - Restart the DN.
 * In the bug, the standby node would only very slowly notice the blocks returning
 * to the cluster.
 */
@Test(timeout=60000)
public void testDatanodeRestarts() throws Exception {
  Configuration conf = new Configuration();
  conf.setInt(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 1024);
  // We read from the standby to watch block locations
  HAUtil.setAllowStandbyReads(conf, true);
  conf.setLong(DFSConfigKeys.DFS_NAMENODE_ACCESSTIME_PRECISION_KEY, 0);
  conf.setInt(DFSConfigKeys.DFS_HA_TAILEDITS_PERIOD_KEY, 1);
  MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
    .nnTopology(MiniDFSNNTopology.simpleHATopology())
    .numDataNodes(1)
    .build();
  try {
    NameNode nn0 = cluster.getNameNode(0);
    NameNode nn1 = cluster.getNameNode(1);

    cluster.transitionToActive(0);
    
    // Create 5 blocks.
    DFSTestUtil.createFile(cluster.getFileSystem(0), 
        TEST_FILE_PATH, 5*1024, (short)1, 1L);
    
    HATestUtil.waitForStandbyToCatchUp(nn0, nn1);
    
    // Stop the DN.
    DataNode dn = cluster.getDataNodes().get(0);
    String dnName = dn.getDatanodeId().getXferAddr(); 
    DataNodeProperties dnProps = cluster.stopDataNode(0);
    
    // Make sure both NNs register it as dead.
    BlockManagerTestUtil.noticeDeadDatanode(nn0, dnName);
    BlockManagerTestUtil.noticeDeadDatanode(nn1, dnName);
    
    BlockManagerTestUtil.updateState(nn0.getNamesystem().getBlockManager());
    BlockManagerTestUtil.updateState(nn1.getNamesystem().getBlockManager());
    assertEquals(5, nn0.getNamesystem().getUnderReplicatedBlocks());
    
    // The SBN will not have any blocks in its neededReplication queue
    // since the SBN doesn't process replication.
    assertEquals(0, nn1.getNamesystem().getUnderReplicatedBlocks());
    
    LocatedBlocks locs = nn1.getRpcServer().getBlockLocations(
        TEST_FILE, 0, 1);
    assertEquals("Standby should have registered that the block has no replicas",
        0, locs.get(0).getLocations().length);
    
    cluster.restartDataNode(dnProps);
    // Wait for both NNs to re-register the DN.
    cluster.waitActive(0);
    cluster.waitActive(1);
    cluster.waitFirstBRCompleted(0, 10000);
    cluster.waitFirstBRCompleted(1, 10000);
    
    BlockManagerTestUtil.updateState(nn0.getNamesystem().getBlockManager());
    BlockManagerTestUtil.updateState(nn1.getNamesystem().getBlockManager());
    assertEquals(0, nn0.getNamesystem().getUnderReplicatedBlocks());
    assertEquals(0, nn1.getNamesystem().getUnderReplicatedBlocks());
    
    locs = nn1.getRpcServer().getBlockLocations(
        TEST_FILE, 0, 1);
    assertEquals("Standby should have registered that the block has replicas again",
        1, locs.get(0).getLocations().length);
  } finally {
    cluster.shutdown();
  }
}