Java ReadaheadPool.getInstance方法代码示例

import org.apache.hadoop.io.ReadaheadPool; //导入方法依赖的package包/类
/**
 * This method starts the data node with the specified conf.
 * 
 * @param conf - the configuration
 *  if conf's CONFIG_PROPERTY_SIMULATED property is set
 *  then a simulated storage based data node is created.
 * 
 * @param dataDirs - only for a non-simulated storage data node
 * @throws IOException
 */
void startDataNode(Configuration conf, 
                   AbstractList<File> dataDirs,
                  // DatanodeProtocol namenode,
                   SecureResources resources
                   ) throws IOException {
  if(UserGroupInformation.isSecurityEnabled() && resources == null) {
    if (!conf.getBoolean("ignore.secure.ports.for.testing", false)) {
      throw new RuntimeException("Cannot start secure cluster without "
          + "privileged resources.");
    }
  }

  // settings global for all BPs in the Data Node
  this.secureResources = resources;
  this.dataDirs = dataDirs;
  this.conf = conf;
  this.dnConf = new DNConf(conf);

  storage = new DataStorage();
  
  // global DN settings
  registerMXBean();
  initDataXceiver(conf);
  startInfoServer(conf);

  // BlockPoolTokenSecretManager is required to create ipc server.
  this.blockPoolTokenSecretManager = new BlockPoolTokenSecretManager();
  initIpcServer(conf);

  metrics = DataNodeMetrics.create(conf, getDisplayName());

  blockPoolManager = new BlockPoolManager(this);
  blockPoolManager.refreshNamenodes(conf);

  // Create the ReadaheadPool from the DataNode context so we can
  // exit without having to explicitly shutdown its thread pool.
  readaheadPool = ReadaheadPool.getInstance();
}
 

import org.apache.hadoop.io.ReadaheadPool; //导入方法依赖的package包/类
/**
 * This method starts the data node with the specified conf.
 *
 * @param conf
 *     - the configuration
 *     if conf's CONFIG_PROPERTY_SIMULATED property is set
 *     then a simulated storage based data node is created.
 * @param dataDirs
 *     - only for a non-simulated storage data node
 * @throws IOException
 */
void startDataNode(Configuration conf, AbstractList<File> dataDirs,
    // DatanodeProtocol namenode,
    SecureResources resources) throws IOException {
  if (UserGroupInformation.isSecurityEnabled() && resources == null) {
    if (!conf.getBoolean("ignore.secure.ports.for.testing", false)) {
      throw new RuntimeException(
          "Cannot start secure cluster without " + "privileged resources.");
    }
  }

  // settings global for all BPs in the Data Node
  this.secureResources = resources;
  this.dataDirs = dataDirs;
  this.conf = conf;
  this.dnConf = new DNConf(conf);

  storage = new DataStorage();
  
  // global DN settings
  registerMXBean();
  initDataXceiver(conf);
  startInfoServer(conf);

  // BlockPoolTokenSecretManager is required to create ipc server.
  this.blockPoolTokenSecretManager = new BlockPoolTokenSecretManager();
  initIpcServer(conf);

  metrics = DataNodeMetrics.create(conf, getDisplayName());

  blockPoolManager = new BlockPoolManager(this);
  blockPoolManager.refreshNamenodes(conf);

  // Create the ReadaheadPool from the DataNode context so we can
  // exit without having to explicitly shutdown its thread pool.
  readaheadPool = ReadaheadPool.getInstance();
}
 

import org.apache.hadoop.io.ReadaheadPool; //导入方法依赖的package包/类
/**
 * This method starts the data node with the specified conf.
 * 
 * @param conf - the configuration
 *  if conf's CONFIG_PROPERTY_SIMULATED property is set
 *  then a simulated storage based data node is created.
 * 
 * @param dataDirs - only for a non-simulated storage data node
 * @throws IOException
 */
void startDataNode(Configuration conf, 
                   List<StorageLocation> dataDirs,
                  // DatanodeProtocol namenode,
                   SecureResources resources
                   ) throws IOException {
  if(UserGroupInformation.isSecurityEnabled() && resources == null) {
    if (!conf.getBoolean("ignore.secure.ports.for.testing", false)) {
      throw new RuntimeException("Cannot start secure cluster without "
          + "privileged resources.");
    }
  }

  // settings global for all BPs in the Data Node
  this.secureResources = resources;
  this.dataDirs = dataDirs;
  this.conf = conf;
  this.dnConf = new DNConf(conf);

  if (dnConf.maxLockedMemory > 0) {
    if (!NativeIO.POSIX.getCacheManipulator().verifyCanMlock()) {
      throw new RuntimeException(String.format(
          "Cannot start datanode because the configured max locked memory" +
          " size (%s) is greater than zero and native code is not available.",
          DFS_DATANODE_MAX_LOCKED_MEMORY_KEY));
    }
    long ulimit = NativeIO.POSIX.getCacheManipulator().getMemlockLimit();
    if (dnConf.maxLockedMemory > ulimit) {
    throw new RuntimeException(String.format(
        "Cannot start datanode because the configured max locked memory" +
        " size (%s) of %d bytes is more than the datanode's available" +
        " RLIMIT_MEMLOCK ulimit of %d bytes.",
        DFS_DATANODE_MAX_LOCKED_MEMORY_KEY,
        dnConf.maxLockedMemory,
        ulimit));
    }
  }
  LOG.info("Starting DataNode with maxLockedMemory = " +
      dnConf.maxLockedMemory);

  storage = new DataStorage();
  
  // global DN settings
  registerMXBean();
  initDataXceiver(conf);
  startInfoServer(conf);
  pauseMonitor = new JvmPauseMonitor(conf);
  pauseMonitor.start();

  // BlockPoolTokenSecretManager is required to create ipc server.
  this.blockPoolTokenSecretManager = new BlockPoolTokenSecretManager();
  initIpcServer(conf);

  metrics = DataNodeMetrics.create(conf, getDisplayName());

  blockPoolManager = new BlockPoolManager(this);
  blockPoolManager.refreshNamenodes(conf);

  // Create the ReadaheadPool from the DataNode context so we can
  // exit without having to explicitly shutdown its thread pool.
  readaheadPool = ReadaheadPool.getInstance();
}