How to use

writeResponse

method

in

org.apache.hadoop.hdfs.server.datanode.DataXceiver

/**
 * Utility function for sending a response.
 * 
 * @param status status message to write
 * @param message message to send to the client or other DN
 */
private void sendResponse(Status status,
  String message) throws IOException {
 writeResponse(status, message, getOutputStream());
}

@Override
public void transferBlock(final ExtendedBlock blk,
  final Token<BlockTokenIdentifier> blockToken,
  final String clientName,
  final DatanodeInfo[] targets,
  final StorageType[] targetStorageTypes,
  final String[] targetStorageIds) throws IOException {
 previousOpClientName = clientName;
 updateCurrentThreadName(Op.TRANSFER_BLOCK + " " + blk);
 final DataOutputStream out = new DataOutputStream(
   getOutputStream());
 checkAccess(out, true, blk, blockToken, Op.TRANSFER_BLOCK,
   BlockTokenIdentifier.AccessMode.COPY, targetStorageTypes,
   targetStorageIds);
 try {
  datanode.transferReplicaForPipelineRecovery(blk, targets,
    targetStorageTypes, targetStorageIds, clientName);
  writeResponse(Status.SUCCESS, null, out);
 } catch (IOException ioe) {
  LOG.info("transferBlock {} received exception {}",
    blk, ioe.toString());
  incrDatanodeNetworkErrors();
  throw ioe;
 } finally {
  IOUtils.closeStream(out);
 }
}

writeResponse(SUCCESS, null, replyOut);

/**
 * Utility function for sending a response.
 * 
 * @param status status message to write
 * @param message message to send to the client or other DN
 */
private void sendResponse(Status status,
  String message) throws IOException {
 writeResponse(status, message, getOutputStream());
}

/**
 * Utility function for sending a response.
 * 
 * @param status status message to write
 * @param message message to send to the client or other DN
 */
private void sendResponse(Status status,
  String message) throws IOException {
 writeResponse(status, message, getOutputStream());
}

@Override
public void transferBlock(final ExtendedBlock blk,
  final Token<BlockTokenIdentifier> blockToken,
  final String clientName,
  final DatanodeInfo[] targets,
  final StorageType[] targetStorageTypes) throws IOException {
 previousOpClientName = clientName;
 updateCurrentThreadName(Op.TRANSFER_BLOCK + " " + blk);
 final DataOutputStream out = new DataOutputStream(
   getOutputStream());
 checkAccess(out, true, blk, blockToken,
   Op.TRANSFER_BLOCK, BlockTokenSecretManager.AccessMode.COPY);
 try {
  datanode.transferReplicaForPipelineRecovery(blk, targets,
    targetStorageTypes, clientName);
  writeResponse(Status.SUCCESS, null, out);
 } catch (IOException ioe) {
  LOG.info("transferBlock " + blk + " received exception " + ioe);
  incrDatanodeNetworkErrors();
  throw ioe;
 } finally {
  IOUtils.closeStream(out);
 }
}

@Override
public void transferBlock(final ExtendedBlock blk,
  final Token<BlockTokenIdentifier> blockToken,
  final String clientName,
  final DatanodeInfo[] targets,
  final StorageType[] targetStorageTypes) throws IOException {
 previousOpClientName = clientName;
 updateCurrentThreadName(Op.TRANSFER_BLOCK + " " + blk);
 final DataOutputStream out = new DataOutputStream(
   getOutputStream());
 checkAccess(out, true, blk, blockToken,
   Op.TRANSFER_BLOCK, BlockTokenSecretManager.AccessMode.COPY);
 try {
  datanode.transferReplicaForPipelineRecovery(blk, targets,
    targetStorageTypes, clientName);
  writeResponse(Status.SUCCESS, null, out);
 } catch (IOException ioe) {
  LOG.info("transferBlock " + blk + " received exception " + ioe);
  incrDatanodeNetworkErrors();
  throw ioe;
 } finally {
  IOUtils.closeStream(out);
 }
}

 LOG.trace("TRANSFER: send close-ack");
writeResponse(SUCCESS, null, replyOut);

 LOG.trace("TRANSFER: send close-ack");
writeResponse(SUCCESS, null, replyOut);