Java ReplicaAlreadyExistsException类代码示例

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaInPipeline createRbw(ExtendedBlock b)
    throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(), 
      b.getBlockId());
  if (replicaInfo != null) {
    throw new ReplicaAlreadyExistsException("Block " + b +
    " already exists in state " + replicaInfo.getState() +
    " and thus cannot be created.");
  }
  // create a new block
  FsVolumeImpl v = volumes.getNextVolume(b.getNumBytes());
  // create a rbw file to hold block in the designated volume
  File f = v.createRbwFile(b.getBlockPoolId(), b.getLocalBlock());
  ReplicaBeingWritten newReplicaInfo = new ReplicaBeingWritten(b.getBlockId(), 
      b.getGenerationStamp(), v, f.getParentFile());
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
  return newReplicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaInPipeline createTemporary(ExtendedBlock b)
    throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(), b.getBlockId());
  if (replicaInfo != null) {
    throw new ReplicaAlreadyExistsException("Block " + b +
        " already exists in state " + replicaInfo.getState() +
        " and thus cannot be created.");
  }
  
  FsVolumeImpl v = volumes.getNextVolume(b.getNumBytes());
  // create a temporary file to hold block in the designated volume
  File f = v.createTmpFile(b.getBlockPoolId(), b.getLocalBlock());
  ReplicaInPipeline newReplicaInfo = new ReplicaInPipeline(b.getBlockId(), 
      b.getGenerationStamp(), v, f.getParentFile());
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
  
  return newReplicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaInPipeline createTemporary(StorageType storageType,
    ExtendedBlock b) throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(), b.getBlockId());
  if (replicaInfo != null) {
    if (replicaInfo.getGenerationStamp() < b.getGenerationStamp()
        && replicaInfo instanceof ReplicaInPipeline) {
      // Stop the previous writer
      ((ReplicaInPipeline)replicaInfo)
                    .stopWriter(datanode.getDnConf().getXceiverStopTimeout());
      invalidate(b.getBlockPoolId(), new Block[]{replicaInfo});
    } else {
      throw new ReplicaAlreadyExistsException("Block " + b +
          " already exists in state " + replicaInfo.getState() +
          " and thus cannot be created.");
    }
  }
  
  FsVolumeImpl v = volumes.getNextVolume(storageType, b.getNumBytes());
  // create a temporary file to hold block in the designated volume
  File f = v.createTmpFile(b.getBlockPoolId(), b.getLocalBlock());
  ReplicaInPipeline newReplicaInfo = new ReplicaInPipeline(b.getBlockId(), 
      b.getGenerationStamp(), v, f.getParentFile(), 0);
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
  return newReplicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaInPipeline createRbw(ExtendedBlock b)
    throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(), b.getBlockId());
  if (replicaInfo != null) {
    throw new ReplicaAlreadyExistsException("Block " + b +
        " already exists in state " + replicaInfo.getState() +
        " and thus cannot be created.");
  }
  // create a new block
  FsVolumeImpl v = volumes.getNextVolume(b.getNumBytes());
  // create a rbw file to hold block in the designated volume
  File f = v.createRbwFile(b.getBlockPoolId(), b.getLocalBlock());
  ReplicaBeingWritten newReplicaInfo =
      new ReplicaBeingWritten(b.getBlockId(), b.getGenerationStamp(), v,
          f.getParentFile());
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
  return newReplicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaInPipeline createTemporary(ExtendedBlock b)
    throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(), b.getBlockId());
  if (replicaInfo != null) {
    throw new ReplicaAlreadyExistsException("Block " + b +
        " already exists in state " + replicaInfo.getState() +
        " and thus cannot be created.");
  }
  
  FsVolumeImpl v = volumes.getNextVolume(b.getNumBytes());
  // create a temporary file to hold block in the designated volume
  File f = v.createTmpFile(b.getBlockPoolId(), b.getLocalBlock());
  ReplicaInPipeline newReplicaInfo =
      new ReplicaInPipeline(b.getBlockId(), b.getGenerationStamp(), v,
          f.getParentFile());
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
  
  return newReplicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaHandler createTemporary(
    StorageType storageType, ExtendedBlock b) throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(), b.getBlockId());
  if (replicaInfo != null) {
    if (replicaInfo.getGenerationStamp() < b.getGenerationStamp()
        && replicaInfo instanceof ReplicaInPipeline) {
      // Stop the previous writer
      ((ReplicaInPipeline)replicaInfo)
                    .stopWriter(datanode.getDnConf().getXceiverStopTimeout());
      invalidate(b.getBlockPoolId(), new Block[]{replicaInfo});
    } else {
      throw new ReplicaAlreadyExistsException("Block " + b +
          " already exists in state " + replicaInfo.getState() +
          " and thus cannot be created.");
    }
  }

  FsVolumeReference ref = volumes.getNextVolume(storageType, b.getNumBytes());
  FsVolumeImpl v = (FsVolumeImpl) ref.getVolume();
  // create a temporary file to hold block in the designated volume
  File f;
  try {
    f = v.createTmpFile(b.getBlockPoolId(), b.getLocalBlock());
  } catch (IOException e) {
    IOUtils.cleanup(null, ref);
    throw e;
  }

  ReplicaInPipeline newReplicaInfo = new ReplicaInPipeline(b.getBlockId(), 
      b.getGenerationStamp(), v, f.getParentFile(), 0);
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
  return new ReplicaHandler(newReplicaInfo, ref);
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaInPipeline createRbw(StorageType storageType,
    ExtendedBlock b, boolean allowLazyPersist) throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(),
      b.getBlockId());
  if (replicaInfo != null) {
    throw new ReplicaAlreadyExistsException("Block " + b +
    " already exists in state " + replicaInfo.getState() +
    " and thus cannot be created.");
  }
  // create a new block
  FsVolumeImpl v;
  while (true) {
    try {
      if (allowLazyPersist) {
        // First try to place the block on a transient volume.
        v = volumes.getNextTransientVolume(b.getNumBytes());
        datanode.getMetrics().incrRamDiskBlocksWrite();
      } else {
        v = volumes.getNextVolume(storageType, b.getNumBytes());
      }
    } catch (DiskOutOfSpaceException de) {
      if (allowLazyPersist) {
        datanode.getMetrics().incrRamDiskBlocksWriteFallback();
        allowLazyPersist = false;
        continue;
      }
      throw de;
    }
    break;
  }
  // create an rbw file to hold block in the designated volume
  File f = v.createRbwFile(b.getBlockPoolId(), b.getLocalBlock());
  ReplicaBeingWritten newReplicaInfo = new ReplicaBeingWritten(b.getBlockId(), 
      b.getGenerationStamp(), v, f.getParentFile(), b.getNumBytes());
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);

  return newReplicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
/**
 * Move block files from one storage to another storage.
 * @return Returns the Old replicaInfo
 * @throws IOException
 */
@Override
public ReplicaInfo moveBlockAcrossStorage(ExtendedBlock block,
    StorageType targetStorageType) throws IOException {
  ReplicaInfo replicaInfo = getReplicaInfo(block);
  if (replicaInfo.getState() != ReplicaState.FINALIZED) {
    throw new ReplicaNotFoundException(
        ReplicaNotFoundException.UNFINALIZED_REPLICA + block);
  }
  if (replicaInfo.getNumBytes() != block.getNumBytes()) {
    throw new IOException("Corrupted replica " + replicaInfo
        + " with a length of " + replicaInfo.getNumBytes()
        + " expected length is " + block.getNumBytes());
  }
  if (replicaInfo.getVolume().getStorageType() == targetStorageType) {
    throw new ReplicaAlreadyExistsException("Replica " + replicaInfo
        + " already exists on storage " + targetStorageType);
  }

  if (replicaInfo.isOnTransientStorage()) {
    // Block movement from RAM_DISK will be done by LazyPersist mechanism
    throw new IOException("Replica " + replicaInfo
        + " cannot be moved from storageType : "
        + replicaInfo.getVolume().getStorageType());
  }

  try (FsVolumeReference volumeRef = volumes.getNextVolume(
      targetStorageType, block.getNumBytes())) {
    File oldBlockFile = replicaInfo.getBlockFile();
    File oldMetaFile = replicaInfo.getMetaFile();
    FsVolumeImpl targetVolume = (FsVolumeImpl) volumeRef.getVolume();
    // Copy files to temp dir first
    File[] blockFiles = copyBlockFiles(block.getBlockId(),
        block.getGenerationStamp(), oldMetaFile, oldBlockFile,
        targetVolume.getTmpDir(block.getBlockPoolId()),
        replicaInfo.isOnTransientStorage());

    ReplicaInfo newReplicaInfo = new ReplicaInPipeline(
        replicaInfo.getBlockId(), replicaInfo.getGenerationStamp(),
        targetVolume, blockFiles[0].getParentFile(), 0);
    newReplicaInfo.setNumBytes(blockFiles[1].length());
    // Finalize the copied files
    newReplicaInfo = finalizeReplica(block.getBlockPoolId(), newReplicaInfo);

    removeOldReplica(replicaInfo, newReplicaInfo, oldBlockFile, oldMetaFile,
        oldBlockFile.length(), oldMetaFile.length(), block.getBlockPoolId());
  }

  // Replace the old block if any to reschedule the scanning.
  return replicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
private ReplicaInfo recoverCheck(ExtendedBlock b, long newGS, 
    long expectedBlockLen) throws IOException {
  ReplicaInfo replicaInfo = getReplicaInfo(b.getBlockPoolId(), b.getBlockId());
  
  // check state
  if (replicaInfo.getState() != ReplicaState.FINALIZED &&
      replicaInfo.getState() != ReplicaState.RBW) {
    throw new ReplicaNotFoundException(
        ReplicaNotFoundException.UNFINALIZED_AND_NONRBW_REPLICA + replicaInfo);
  }

  // check generation stamp
  long replicaGenerationStamp = replicaInfo.getGenerationStamp();
  if (replicaGenerationStamp < b.getGenerationStamp() ||
      replicaGenerationStamp > newGS) {
    throw new ReplicaNotFoundException(
        ReplicaNotFoundException.UNEXPECTED_GS_REPLICA + replicaGenerationStamp
        + ". Expected GS range is [" + b.getGenerationStamp() + ", " + 
        newGS + "].");
  }
  
  // stop the previous writer before check a replica's length
  long replicaLen = replicaInfo.getNumBytes();
  if (replicaInfo.getState() == ReplicaState.RBW) {
    ReplicaBeingWritten rbw = (ReplicaBeingWritten)replicaInfo;
    // kill the previous writer
    rbw.stopWriter(datanode.getDnConf().getXceiverStopTimeout());
    rbw.setWriter(Thread.currentThread());
    // check length: bytesRcvd, bytesOnDisk, and bytesAcked should be the same
    if (replicaLen != rbw.getBytesOnDisk() 
        || replicaLen != rbw.getBytesAcked()) {
      throw new ReplicaAlreadyExistsException("RBW replica " + replicaInfo + 
          "bytesRcvd(" + rbw.getNumBytes() + "), bytesOnDisk(" + 
          rbw.getBytesOnDisk() + "), and bytesAcked(" + rbw.getBytesAcked() +
          ") are not the same.");
    }
  }
  
  // check block length
  if (replicaLen != expectedBlockLen) {
    throw new IOException("Corrupted replica " + replicaInfo + 
        " with a length of " + replicaLen + 
        " expected length is " + expectedBlockLen);
  }
  
  return replicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaHandler createRbw(
    StorageType storageType, ExtendedBlock b, boolean allowLazyPersist)
    throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(),
      b.getBlockId());
  if (replicaInfo != null) {
    throw new ReplicaAlreadyExistsException("Block " + b +
    " already exists in state " + replicaInfo.getState() +
    " and thus cannot be created.");
  }
  // create a new block
  FsVolumeReference ref;
  while (true) {
    try {
      if (allowLazyPersist) {
        // First try to place the block on a transient volume.
        ref = volumes.getNextTransientVolume(b.getNumBytes());
        datanode.getMetrics().incrRamDiskBlocksWrite();
      } else {
        ref = volumes.getNextVolume(storageType, b.getNumBytes());
      }
    } catch (DiskOutOfSpaceException de) {
      if (allowLazyPersist) {
        datanode.getMetrics().incrRamDiskBlocksWriteFallback();
        allowLazyPersist = false;
        continue;
      }
      throw de;
    }
    break;
  }
  FsVolumeImpl v = (FsVolumeImpl) ref.getVolume();
  // create an rbw file to hold block in the designated volume
  File f;
  try {
    f = v.createRbwFile(b.getBlockPoolId(), b.getLocalBlock());
  } catch (IOException e) {
    IOUtils.cleanup(null, ref);
    throw e;
  }

  ReplicaBeingWritten newReplicaInfo = new ReplicaBeingWritten(b.getBlockId(), 
      b.getGenerationStamp(), v, f.getParentFile(), b.getNumBytes());
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
  return new ReplicaHandler(newReplicaInfo, ref);
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public ReplicaHandler createTemporary(
    StorageType storageType, ExtendedBlock b) throws IOException {
  long startTimeMs = Time.monotonicNow();
  long writerStopTimeoutMs = datanode.getDnConf().getXceiverStopTimeout();
  ReplicaInfo lastFoundReplicaInfo = null;
  do {
    synchronized (this) {
      ReplicaInfo currentReplicaInfo =
          volumeMap.get(b.getBlockPoolId(), b.getBlockId());
      if (currentReplicaInfo == lastFoundReplicaInfo) {
        if (lastFoundReplicaInfo != null) {
          invalidate(b.getBlockPoolId(), new Block[] { lastFoundReplicaInfo });
        }
        FsVolumeReference ref =
            volumes.getNextVolume(storageType, b.getNumBytes());
        FsVolumeImpl v = (FsVolumeImpl) ref.getVolume();
        // create a temporary file to hold block in the designated volume
        File f;
        try {
          f = v.createTmpFile(b.getBlockPoolId(), b.getLocalBlock());
        } catch (IOException e) {
          IOUtils.cleanup(null, ref);
          throw e;
        }
        ReplicaInPipeline newReplicaInfo =
            new ReplicaInPipeline(b.getBlockId(), b.getGenerationStamp(), v,
                f.getParentFile(), 0);
        volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
        return new ReplicaHandler(newReplicaInfo, ref);
      } else {
        if (!(currentReplicaInfo.getGenerationStamp() < b
            .getGenerationStamp() && currentReplicaInfo instanceof ReplicaInPipeline)) {
          throw new ReplicaAlreadyExistsException("Block " + b
              + " already exists in state " + currentReplicaInfo.getState()
              + " and thus cannot be created.");
        }
        lastFoundReplicaInfo = currentReplicaInfo;
      }
    }

    // Hang too long, just bail out. This is not supposed to happen.
    long writerStopMs = Time.monotonicNow() - startTimeMs;
    if (writerStopMs > writerStopTimeoutMs) {
      LOG.warn("Unable to stop existing writer for block " + b + " after " 
          + writerStopMs + " miniseconds.");
      throw new IOException("Unable to stop existing writer for block " + b
          + " after " + writerStopMs + " miniseconds.");
    }

    // Stop the previous writer
    ((ReplicaInPipeline) lastFoundReplicaInfo)
        .stopWriter(writerStopTimeoutMs);
  } while (true);
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
/**
 * Move block files from one storage to another storage.
 * @return Returns the Old replicaInfo
 * @throws IOException
 */
@Override
public ReplicaInfo moveBlockAcrossStorage(ExtendedBlock block,
    StorageType targetStorageType) throws IOException {
  ReplicaInfo replicaInfo = getReplicaInfo(block);
  if (replicaInfo.getState() != ReplicaState.FINALIZED) {
    throw new ReplicaNotFoundException(
        ReplicaNotFoundException.UNFINALIZED_REPLICA + block);
  }
  if (replicaInfo.getNumBytes() != block.getNumBytes()) {
    throw new IOException("Corrupted replica " + replicaInfo
        + " with a length of " + replicaInfo.getNumBytes()
        + " expected length is " + block.getNumBytes());
  }
  if (replicaInfo.getVolume().getStorageType() == targetStorageType) {
    throw new ReplicaAlreadyExistsException("Replica " + replicaInfo
        + " already exists on storage " + targetStorageType);
  }

  if (replicaInfo.isOnTransientStorage()) {
    // Block movement from RAM_DISK will be done by LazyPersist mechanism
    throw new IOException("Replica " + replicaInfo
        + " cannot be moved from storageType : "
        + replicaInfo.getVolume().getStorageType());
  }

  try (FsVolumeReference volumeRef = volumes.getNextVolume(
      targetStorageType, block.getNumBytes())) {
    File oldBlockFile = replicaInfo.getBlockFile();
    File oldMetaFile = replicaInfo.getMetaFile();
    FsVolumeImpl targetVolume = (FsVolumeImpl) volumeRef.getVolume();
    // Copy files to temp dir first
    File[] blockFiles = copyBlockFiles(block.getBlockId(),
        block.getGenerationStamp(), oldMetaFile, oldBlockFile,
        targetVolume.getTmpDir(block.getBlockPoolId()),
        replicaInfo.isOnTransientStorage(), smallBufferSize, conf);

    ReplicaInfo newReplicaInfo = new ReplicaInPipeline(
        replicaInfo.getBlockId(), replicaInfo.getGenerationStamp(),
        targetVolume, blockFiles[0].getParentFile(), 0);
    newReplicaInfo.setNumBytes(blockFiles[1].length());
    // Finalize the copied files
    newReplicaInfo = finalizeReplica(block.getBlockPoolId(), newReplicaInfo);

    removeOldReplica(replicaInfo, newReplicaInfo, oldBlockFile, oldMetaFile,
        oldBlockFile.length(), oldMetaFile.length(), block.getBlockPoolId());
  }

  // Replace the old block if any to reschedule the scanning.
  return replicaInfo;
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public synchronized ReplicaHandler createRbw(
    StorageType storageType, ExtendedBlock b, boolean allowLazyPersist)
    throws IOException {
  ReplicaInfo replicaInfo = volumeMap.get(b.getBlockPoolId(),
      b.getBlockId());
  if (replicaInfo != null) {
    throw new ReplicaAlreadyExistsException("Block " + b +
    " already exists in state " + replicaInfo.getState() +
    " and thus cannot be created.");
  }
  // create a new block
  FsVolumeReference ref = null;

  // Use ramdisk only if block size is a multiple of OS page size.
  // This simplifies reservation for partially used replicas
  // significantly.
  if (allowLazyPersist &&
      lazyWriter != null &&
      b.getNumBytes() % cacheManager.getOsPageSize() == 0 &&
      reserveLockedMemory(b.getNumBytes())) {
    try {
      // First try to place the block on a transient volume.
      ref = volumes.getNextTransientVolume(b.getNumBytes());
      datanode.getMetrics().incrRamDiskBlocksWrite();
    } catch(DiskOutOfSpaceException de) {
      // Ignore the exception since we just fall back to persistent storage.
    } finally {
      if (ref == null) {
        cacheManager.release(b.getNumBytes());
      }
    }
  }

  if (ref == null) {
    ref = volumes.getNextVolume(storageType, b.getNumBytes());
  }

  FsVolumeImpl v = (FsVolumeImpl) ref.getVolume();
  // create an rbw file to hold block in the designated volume

  if (allowLazyPersist && !v.isTransientStorage()) {
    datanode.getMetrics().incrRamDiskBlocksWriteFallback();
  }

  File f;
  try {
    f = v.createRbwFile(b.getBlockPoolId(), b.getLocalBlock());
  } catch (IOException e) {
    IOUtils.cleanup(null, ref);
    throw e;
  }

  ReplicaBeingWritten newReplicaInfo = new ReplicaBeingWritten(b.getBlockId(), 
      b.getGenerationStamp(), v, f.getParentFile(), b.getNumBytes());
  volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
  return new ReplicaHandler(newReplicaInfo, ref);
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
@Override // FsDatasetSpi
public ReplicaHandler createTemporary(
    StorageType storageType, ExtendedBlock b) throws IOException {
  long startTimeMs = Time.monotonicNow();
  long writerStopTimeoutMs = datanode.getDnConf().getXceiverStopTimeout();
  ReplicaInfo lastFoundReplicaInfo = null;
  do {
    synchronized (this) {
      ReplicaInfo currentReplicaInfo =
          volumeMap.get(b.getBlockPoolId(), b.getBlockId());
      if (currentReplicaInfo == lastFoundReplicaInfo) {
        if (lastFoundReplicaInfo != null) {
          invalidate(b.getBlockPoolId(), new Block[] { lastFoundReplicaInfo });
        }
        FsVolumeReference ref =
            volumes.getNextVolume(storageType, b.getNumBytes());
        FsVolumeImpl v = (FsVolumeImpl) ref.getVolume();
        // create a temporary file to hold block in the designated volume
        File f;
        try {
          f = v.createTmpFile(b.getBlockPoolId(), b.getLocalBlock());
        } catch (IOException e) {
          IOUtils.cleanup(null, ref);
          throw e;
        }
        ReplicaInPipeline newReplicaInfo =
            new ReplicaInPipeline(b.getBlockId(), b.getGenerationStamp(), v,
                f.getParentFile(), b.getLocalBlock().getNumBytes());
        volumeMap.add(b.getBlockPoolId(), newReplicaInfo);
        return new ReplicaHandler(newReplicaInfo, ref);
      } else {
        if (!(currentReplicaInfo.getGenerationStamp() < b
            .getGenerationStamp() && currentReplicaInfo instanceof ReplicaInPipeline)) {
          throw new ReplicaAlreadyExistsException("Block " + b
              + " already exists in state " + currentReplicaInfo.getState()
              + " and thus cannot be created.");
        }
        lastFoundReplicaInfo = currentReplicaInfo;
      }
    }

    // Hang too long, just bail out. This is not supposed to happen.
    long writerStopMs = Time.monotonicNow() - startTimeMs;
    if (writerStopMs > writerStopTimeoutMs) {
      LOG.warn("Unable to stop existing writer for block " + b + " after " 
          + writerStopMs + " miniseconds.");
      throw new IOException("Unable to stop existing writer for block " + b
          + " after " + writerStopMs + " miniseconds.");
    }

    // Stop the previous writer
    ((ReplicaInPipeline) lastFoundReplicaInfo)
        .stopWriter(writerStopTimeoutMs);
  } while (true);
}
 

import org.apache.hadoop.hdfs.server.datanode.ReplicaAlreadyExistsException; //导入依赖的package包/类
private ReplicaInfo recoverCheck(ExtendedBlock b, long newGS,
    long expectedBlockLen) throws IOException {
  ReplicaInfo replicaInfo =
      getReplicaInfo(b.getBlockPoolId(), b.getBlockId());
  
  // check state
  if (replicaInfo.getState() != ReplicaState.FINALIZED &&
      replicaInfo.getState() != ReplicaState.RBW) {
    throw new ReplicaNotFoundException(
        ReplicaNotFoundException.UNFINALIZED_AND_NONRBW_REPLICA +
            replicaInfo);
  }

  // check generation stamp
  long replicaGenerationStamp = replicaInfo.getGenerationStamp();
  if (replicaGenerationStamp < b.getGenerationStamp() ||
      replicaGenerationStamp > newGS) {
    throw new ReplicaNotFoundException(
        ReplicaNotFoundException.UNEXPECTED_GS_REPLICA +
            replicaGenerationStamp + ". Expected GS range is [" +
            b.getGenerationStamp() + ", " +
            newGS + "].");
  }
  
  // stop the previous writer before check a replica's length
  long replicaLen = replicaInfo.getNumBytes();
  if (replicaInfo.getState() == ReplicaState.RBW) {
    ReplicaBeingWritten rbw = (ReplicaBeingWritten) replicaInfo;
    // kill the previous writer
    rbw.stopWriter();
    rbw.setWriter(Thread.currentThread());
    // check length: bytesRcvd, bytesOnDisk, and bytesAcked should be the same
    if (replicaLen != rbw.getBytesOnDisk() ||
        replicaLen != rbw.getBytesAcked()) {
      throw new ReplicaAlreadyExistsException("RBW replica " + replicaInfo +
          "bytesRcvd(" + rbw.getNumBytes() + "), bytesOnDisk(" +
          rbw.getBytesOnDisk() + "), and bytesAcked(" + rbw.getBytesAcked() +
          ") are not the same.");
    }
  }
  
  // check block length
  if (replicaLen != expectedBlockLen) {
    throw new IOException("Corrupted replica " + replicaInfo +
        " with a length of " + replicaLen +
        " expected length is " + expectedBlockLen);
  }
  
  return replicaInfo;
}