Spark 提交yarn cluster模式 提交job后 结束client进程

最近有个同事说自己提交了spark job 后，client的进程一直占用内存，而且类似的job提交了很多，最后导致提交job的机器，内存不够用了。
查看了一下该同学的job的deploy mode 是cluster ，也就是提交之后，client的进程会一直运行，直到job结束，但是同学的这个job又是一个Streaming的job，所以不会停下来。最后这个同学采用了一个比较粗暴有效的办法，就是提交完job之后，去checkjob的运行状态，如果是运行中的话，就kill掉client的进程。
今天重新看了下yarn.client的代码发现一个参数
spark.yarn.submit.waitAppCompletion 如果设置这个参数为true的话，client将会一直运行并且报告application的状态直到application退出（无论何种原因）。false的话，client的进程将会在application提交后退出。

  /**
   * Submit an application to the ResourceManager.
   * If set spark.yarn.submit.waitAppCompletion to true, it will stay alive
   * reporting the application's status until the application has exited for any reason.
   * Otherwise, the client process will exit after submission.
   * If the application finishes with a failed, killed, or undefined status,
   * throw an appropriate SparkException.
   */
  def run(): Unit = {
    this.appId = submitApplication()
    if (!launcherBackend.isConnected() && fireAndForget) {
      val report = getApplicationReport(appId)
      val state = report.getYarnApplicationState
      logInfo(s"Application report for $appId (state: $state)")
      logInfo(formatReportDetails(report))
      if (state == YarnApplicationState.FAILED || state == YarnApplicationState.KILLED) {
        throw new SparkException(s"Application $appId finished with status: $state")
      }
    } else {
      val (yarnApplicationState, finalApplicationStatus) = monitorApplication(appId)
      if (yarnApplicationState == YarnApplicationState.FAILED ||
        finalApplicationStatus == FinalApplicationStatus.FAILED) {
        throw new SparkException(s"Application $appId finished with failed status")
      }
      if (yarnApplicationState == YarnApplicationState.KILLED ||
        finalApplicationStatus == FinalApplicationStatus.KILLED) {
        throw new SparkException(s"Application $appId is killed")
      }
      if (finalApplicationStatus == FinalApplicationStatus.UNDEFINED) {
        throw new SparkException(s"The final status of application $appId is undefined")
      }
    }
  }