Java Code Examples for org.apache.hadoop.hdfs.server.namenode.FSNamesystem#readLock()

/** @return the datanode descriptor for the given the given storageID. */
public static DatanodeDescriptor getDatanode(final FSNamesystem ns,
    final String storageID) {
  ns.readLock();
  try {
    return ns.getBlockManager().getDatanodeManager().getDatanode(storageID);
  } finally {
    ns.readUnlock();
  }
}
 

/**
 * @return a tuple of the replica state (number racks, number live
 * replicas, and number needed replicas) for the given block.
 */
public static int[] getReplicaInfo(final FSNamesystem namesystem, final Block b) {
  final BlockManager bm = namesystem.getBlockManager();
  namesystem.readLock();
  try {
    return new int[]{getNumberOfRacks(bm, b),
        bm.countNodes(b).liveReplicas(),
        bm.neededReplications.contains(b) ? 1 : 0};
  } finally {
    namesystem.readUnlock();
  }
}
 

NumberReplicas countNodes(Block block, FSNamesystem namesystem) {
  namesystem.readLock();
  try {
    lastBlock = block;
    lastNum = namesystem.getBlockManager().countNodes(block);
    return lastNum;
  }
  finally {
    namesystem.readUnlock();
  }
}
 

/** @return the datanode descriptor for the given the given storageID. */
public static DatanodeDescriptor getDatanode(final FSNamesystem ns,
    final String storageID) {
  ns.readLock();
  try {
    return ns.getBlockManager().getDatanodeManager().getDatanode(storageID);
  } finally {
    ns.readUnlock();
  }
}
 

/**
 * @return a tuple of the replica state (number racks, number live
 * replicas, and number needed replicas) for the given block.
 */
public static int[] getReplicaInfo(final FSNamesystem namesystem, final Block b) {
  final BlockManager bm = namesystem.getBlockManager();
  namesystem.readLock();
  try {
    return new int[]{getNumberOfRacks(bm, b),
        bm.countNodes(b).liveReplicas(),
        bm.neededReplications.contains(b) ? 1 : 0};
  } finally {
    namesystem.readUnlock();
  }
}
 

NumberReplicas countNodes(Block block, FSNamesystem namesystem) {
  namesystem.readLock();
  try {
    lastBlock = block;
    lastNum = namesystem.getBlockManager().countNodes(block);
    return lastNum;
  }
  finally {
    namesystem.readUnlock();
  }
}
 

/**
 * The test verifies that replica for deletion is chosen on a node,
 * with the oldest heartbeat, when this heartbeat is larger than the
 * tolerable heartbeat interval.
 * It creates a file with several blocks and replication 4.
 * The last DN is configured to send heartbeats rarely.
 * 
 * Test waits until the tolerable heartbeat interval expires, and reduces
 * replication of the file. All replica deletions should be scheduled for the
 * last node. No replicas will actually be deleted, since last DN doesn't
 * send heartbeats. 
 */
@Test
public void testChooseReplicaToDelete() throws Exception {
  MiniDFSCluster cluster = null;
  FileSystem fs = null;
  try {
    Configuration conf = new HdfsConfiguration();
    conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, SMALL_BLOCK_SIZE);
    cluster = new MiniDFSCluster.Builder(conf).numDataNodes(3).build();
    fs = cluster.getFileSystem();
    final FSNamesystem namesystem = cluster.getNamesystem();

    conf.setLong(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 300);
    cluster.startDataNodes(conf, 1, true, null, null, null);
    DataNode lastDN = cluster.getDataNodes().get(3);
    DatanodeRegistration dnReg = DataNodeTestUtils.getDNRegistrationForBP(
        lastDN, namesystem.getBlockPoolId());
    String lastDNid = dnReg.getDatanodeUuid();

    final Path fileName = new Path("/foo2");
    DFSTestUtil.createFile(fs, fileName, SMALL_FILE_LENGTH, (short)4, 0L);
    DFSTestUtil.waitReplication(fs, fileName, (short)4);

    // Wait for tolerable number of heartbeats plus one
    DatanodeDescriptor nodeInfo = null;
    long lastHeartbeat = 0;
    long waitTime = DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_DEFAULT * 1000 *
      (DFSConfigKeys.DFS_NAMENODE_TOLERATE_HEARTBEAT_MULTIPLIER_DEFAULT + 1);
    do {
      nodeInfo = namesystem.getBlockManager().getDatanodeManager()
          .getDatanode(dnReg);
      lastHeartbeat = nodeInfo.getLastUpdateMonotonic();
    } while (monotonicNow() - lastHeartbeat < waitTime);
    fs.setReplication(fileName, (short)3);

    BlockLocation locs[] = fs.getFileBlockLocations(
        fs.getFileStatus(fileName), 0, Long.MAX_VALUE);

    // All replicas for deletion should be scheduled on lastDN.
    // And should not actually be deleted, because lastDN does not heartbeat.
    namesystem.readLock();
    Collection<Block> dnBlocks = 
      namesystem.getBlockManager().excessReplicateMap.get(lastDNid);
    assertEquals("Replicas on node " + lastDNid + " should have been deleted",
        SMALL_FILE_LENGTH / SMALL_BLOCK_SIZE, dnBlocks.size());
    namesystem.readUnlock();
    for(BlockLocation location : locs)
      assertEquals("Block should still have 4 replicas",
          4, location.getNames().length);
  } finally {
    if(fs != null) fs.close();
    if(cluster != null) cluster.shutdown();
  }
}
 

/**
 * The test verifies that replica for deletion is chosen on a node,
 * with the oldest heartbeat, when this heartbeat is larger than the
 * tolerable heartbeat interval.
 * It creates a file with several blocks and replication 4.
 * The last DN is configured to send heartbeats rarely.
 * 
 * Test waits until the tolerable heartbeat interval expires, and reduces
 * replication of the file. All replica deletions should be scheduled for the
 * last node. No replicas will actually be deleted, since last DN doesn't
 * send heartbeats. 
 */
@Test
public void testChooseReplicaToDelete() throws Exception {
  MiniDFSCluster cluster = null;
  FileSystem fs = null;
  try {
    Configuration conf = new HdfsConfiguration();
    conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, SMALL_BLOCK_SIZE);
    cluster = new MiniDFSCluster.Builder(conf).numDataNodes(3).build();
    fs = cluster.getFileSystem();
    final FSNamesystem namesystem = cluster.getNamesystem();

    conf.setLong(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 300);
    cluster.startDataNodes(conf, 1, true, null, null, null);
    DataNode lastDN = cluster.getDataNodes().get(3);
    DatanodeRegistration dnReg = DataNodeTestUtils.getDNRegistrationForBP(
        lastDN, namesystem.getBlockPoolId());
    String lastDNid = dnReg.getDatanodeUuid();

    final Path fileName = new Path("/foo2");
    DFSTestUtil.createFile(fs, fileName, SMALL_FILE_LENGTH, (short)4, 0L);
    DFSTestUtil.waitReplication(fs, fileName, (short)4);

    // Wait for tolerable number of heartbeats plus one
    DatanodeDescriptor nodeInfo = null;
    long lastHeartbeat = 0;
    long waitTime = DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_DEFAULT * 1000 *
      (DFSConfigKeys.DFS_NAMENODE_TOLERATE_HEARTBEAT_MULTIPLIER_DEFAULT + 1);
    do {
      nodeInfo = namesystem.getBlockManager().getDatanodeManager()
          .getDatanode(dnReg);
      lastHeartbeat = nodeInfo.getLastUpdateMonotonic();
    } while (monotonicNow() - lastHeartbeat < waitTime);
    fs.setReplication(fileName, (short)3);

    BlockLocation locs[] = fs.getFileBlockLocations(
        fs.getFileStatus(fileName), 0, Long.MAX_VALUE);

    // All replicas for deletion should be scheduled on lastDN.
    // And should not actually be deleted, because lastDN does not heartbeat.
    namesystem.readLock();
    Collection<Block> dnBlocks = 
      namesystem.getBlockManager().excessReplicateMap.get(lastDNid);
    assertEquals("Replicas on node " + lastDNid + " should have been deleted",
        SMALL_FILE_LENGTH / SMALL_BLOCK_SIZE, dnBlocks.size());
    namesystem.readUnlock();
    for(BlockLocation location : locs)
      assertEquals("Block should still have 4 replicas",
          4, location.getNames().length);
  } finally {
    if(fs != null) fs.close();
    if(cluster != null) cluster.shutdown();
  }
}