import org.apache.hadoop.mapred.AdminOperationsProtocol; //导入依赖的package包/类
private int refreshQueues() throws IOException {
  // Get the current configuration
  Configuration conf = getConf();
  
  // Create the client
  AdminOperationsProtocol adminOperationsProtocol = 
    (AdminOperationsProtocol) 
    RPC.getProxy(AdminOperationsProtocol.class, 
                 AdminOperationsProtocol.versionID, 
                 JobTracker.getAddress(conf), getUGI(conf), conf,
                 NetUtils.getSocketFactory(conf, 
                                           AdminOperationsProtocol.class));
  
  // Refresh the queue properties
  adminOperationsProtocol.refreshQueues();
  
  return 0;
}
 

import org.apache.hadoop.mapred.AdminOperationsProtocol; //导入依赖的package包/类
/**
 * Command to ask the jobtracker to reread the hosts and excluded hosts 
 * file.
 * Usage: java MRAdmin -refreshNodes
 * @exception IOException 
 */
private int refreshNodes() throws IOException {
  // Get the current configuration
  Configuration conf = getConf();
  
  // Create the client
  AdminOperationsProtocol adminOperationsProtocol = 
    (AdminOperationsProtocol) 
    RPC.getProxy(AdminOperationsProtocol.class, 
                 AdminOperationsProtocol.versionID, 
                 JobTracker.getAddress(conf), getUGI(conf), conf,
                 NetUtils.getSocketFactory(conf, 
                                           AdminOperationsProtocol.class));
  
  // Refresh the queue properties
  adminOperationsProtocol.refreshNodes();
  
  return 0;
}
 

import org.apache.hadoop.mapred.AdminOperationsProtocol; //导入依赖的package包/类
private int refreshQueueAcls() throws IOException {
  // Get the current configuration
  Configuration conf = getConf();
  
  // Create the client
  AdminOperationsProtocol adminOperationsProtocol = 
    (AdminOperationsProtocol) 
    RPC.getProxy(AdminOperationsProtocol.class, 
                 AdminOperationsProtocol.versionID, 
                 JobTracker.getAddress(conf), getUGI(conf), conf,
                 NetUtils.getSocketFactory(conf, 
                                           AdminOperationsProtocol.class));
  
  // Refresh the queue properties
  adminOperationsProtocol.refreshQueueAcls();
  
  return 0;
}
 

import org.apache.hadoop.mapred.AdminOperationsProtocol; //导入依赖的package包/类
private int setSafeMode(String actionString) throws IOException {
  JobTracker.SafeModeAction action;
  Boolean waitExitSafe = false;

  if ("leave".equalsIgnoreCase(actionString)) {
    action = JobTracker.SafeModeAction.SAFEMODE_LEAVE;
  } else if ("enter".equalsIgnoreCase(actionString)) {
    action = JobTracker.SafeModeAction.SAFEMODE_ENTER;
  } else if ("get".equalsIgnoreCase(actionString)) {
    action = JobTracker.SafeModeAction.SAFEMODE_GET;
  } else if ("wait".equalsIgnoreCase(actionString)) {
    action = JobTracker.SafeModeAction.SAFEMODE_GET;
    waitExitSafe = true;
  } else {
    printUsage("-safemode");
    return -1;
  }

  // Get the current configuration
  Configuration conf = getConf();
  
  // Create the client
  AdminOperationsProtocol adminOperationsProtocol = 
    (AdminOperationsProtocol) 
    RPC.getProxy(AdminOperationsProtocol.class, 
                 AdminOperationsProtocol.versionID, 
                 JobTracker.getAddress(conf), getUGI(conf), conf,
                 NetUtils.getSocketFactory(conf, 
                                           AdminOperationsProtocol.class));
  

  boolean inSafeMode = adminOperationsProtocol.setSafeMode(action);

  //
  // If we are waiting for safemode to exit, then poll and
  // sleep till we are out of safemode.
  //
  if (waitExitSafe) {
    while (inSafeMode) {
      try {
        Thread.sleep(3000);
      } catch (java.lang.InterruptedException e) {
        throw new IOException("Wait Interrupted");
      }
      inSafeMode = adminOperationsProtocol.setSafeMode(action);
    }
  }

  System.out.println("Safe mode is " + (inSafeMode ? "ON" : "OFF"));

  return 0;
}