AttemptStartedTransition(详见7)

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AttemptStartedTransition(基于hadoop 2.7.6)

主要逻辑:
1.向ApplicationMasterService注册AppAttempt(在ApplicationMasterService服务中以attemptId为键占个坑,后面ApplicationMaster通过allocate发送心跳时,会检查其对应的attempt是否注册过.)
2.触发SchedulerEventType.APP_ATTEMPT_ADDED事件,该事件由CapacityScheduler.handler方法处理.

代码清单

private static final class RMAppAttemptImpl.AttemptStartedTransition extends BaseTransition {
	@Override
    public void transition(RMAppAttemptImpl appAttempt,
        RMAppAttemptEvent event) {
        /**
	     * 		是否从之前的状态恢复,默认写死了是false
	     */
	    boolean transferStateFromPreviousAttempt = false;
	     
      if (event instanceof RMAppStartAttemptEvent) {
        transferStateFromPreviousAttempt =
            ((RMAppStartAttemptEvent) event)
              .getTransferStateFromPreviousAttempt();
      }
      appAttempt.startTime = System.currentTimeMillis();
      /**
      *1.实例化应答类AllocateResponse,将ResponseId初始化-1.
      
      *2.在ApplicationMasterService服务中根据attemptId占个坑,后面ApplicationMaster通过allocate发送心跳时,会检查其对应的attempt是否注册过.
      */
      appAttempt.masterService
    .registerAppAttempt(appAttempt.applicationAttemptId);

      if (UserGroupInformation.isSecurityEnabled()) {
        appAttempt.clientTokenMasterKey =
            appAttempt.rmContext.getClientToAMTokenSecretManager().createMasterKey(appAttempt.applicationAttemptId);
      }
      appAttempt.eventHandler.handle(new AppAttemptAddedSchedulerEvent(
        appAttempt.applicationAttemptId, transferStateFromPreviousAttempt));
    }
  }

---

这里的masterService服务是随着ResourceManager初始化的，就是ApplicationMasterService类，见ResourceManager的初始化代码:

ResourceManager.RMActiveService.serviceInit(){
...省略...
masterService = createApplicationMasterService();
      addService(masterService) ;
    rmContext.setApplicationMasterService(masterService);
...省略...
}

SchedulerEventType.APP_ATTEMPT_ADDED的处理器是哪个,可以参考AddApplicationToSchedulerTransition(详见4)的思路去定位代码.