python - 作业完成后 spark-submit 继续挂起

Question

我正在尝试在 AWS 中使用 hdfs 测试 spark 1.6。我正在使用示例文件夹中可用的 wordcount python 示例。我使用 spark-submit 提交作业，作业成功完成，并且也在控制台上打印结果。 Web 用户界面还表示已完成。然而， Spark 提交永远不会终止。我已经验证上下文在字数统计示例代码中也已停止。

有什么问题吗？

这是我在控制台上看到的。

6-05-24 14:58:04,749 INFO  [Thread-3] handler.ContextHandler (ContextHandler.java:doStop(843)) - stopped o.s.j.s.ServletContextHandler{/stages/stage,null}
2016-05-24 14:58:04,749 INFO  [Thread-3] handler.ContextHandler (ContextHandler.java:doStop(843)) - stopped o.s.j.s.ServletContextHandler{/stages/json,null}
2016-05-24 14:58:04,749 INFO  [Thread-3] handler.ContextHandler (ContextHandler.java:doStop(843)) - stopped o.s.j.s.ServletContextHandler{/stages,null}
2016-05-24 14:58:04,749 INFO  [Thread-3] handler.ContextHandler (ContextHandler.java:doStop(843)) - stopped o.s.j.s.ServletContextHandler{/jobs/job/json,null}
2016-05-24 14:58:04,750 INFO  [Thread-3] handler.ContextHandler (ContextHandler.java:doStop(843)) - stopped o.s.j.s.ServletContextHandler{/jobs/job,null}
2016-05-24 14:58:04,750 INFO  [Thread-3] handler.ContextHandler (ContextHandler.java:doStop(843)) - stopped o.s.j.s.ServletContextHandler{/jobs/json,null}
2016-05-24 14:58:04,750 INFO  [Thread-3] handler.ContextHandler (ContextHandler.java:doStop(843)) - stopped o.s.j.s.ServletContextHandler{/jobs,null}
2016-05-24 14:58:04,802 INFO  [Thread-3] ui.SparkUI (Logging.scala:logInfo(58)) - Stopped Spark web UI at http://172.30.2.239:4040
2016-05-24 14:58:04,805 INFO  [Thread-3] cluster.SparkDeploySchedulerBackend (Logging.scala:logInfo(58)) - Shutting down all executors
2016-05-24 14:58:04,805 INFO  [dispatcher-event-loop-2] cluster.SparkDeploySchedulerBackend (Logging.scala:logInfo(58)) - Asking each executor to shut down
2016-05-24 14:58:04,814 INFO  [dispatcher-event-loop-5] spark.MapOutputTrackerMasterEndpoint (Logging.scala:logInfo(58)) - MapOutputTrackerMasterEndpoint stopped!
2016-05-24 14:58:04,818 INFO  [Thread-3] storage.MemoryStore (Logging.scala:logInfo(58)) - MemoryStore cleared
2016-05-24 14:58:04,818 INFO  [Thread-3] storage.BlockManager (Logging.scala:logInfo(58)) - BlockManager stopped
2016-05-24 14:58:04,820 INFO  [Thread-3] storage.BlockManagerMaster (Logging.scala:logInfo(58)) - BlockManagerMaster stopped
2016-05-24 14:58:04,821 INFO  [dispatcher-event-loop-3] scheduler.OutputCommitCoordinator$OutputCommitCoordinatorEndpoint (Logging.scala:logInfo(58)) - OutputCommitCoordinator stopped!
2016-05-24 14:58:04,824 INFO  [Thread-3] spark.SparkContext (Logging.scala:logInfo(58)) - Successfully stopped SparkContext
2016-05-24 14:58:04,827 INFO  [sparkDriverActorSystem-akka.actor.default-dispatcher-2] remote.RemoteActorRefProvider$RemotingTerminator (Slf4jLogger.scala:apply$mcV$sp(74)) - Shutting down remote daemon.
2016-05-24 14:58:04,828 INFO  [sparkDriverActorSystem-akka.actor.default-dispatcher-2] remote.RemoteActorRefProvider$RemotingTerminator (Slf4jLogger.scala:apply$mcV$sp(74)) - Remote daemon shut down; proceeding with flushing remote transports.
2016-05-24 14:58:04,843 INFO  [sparkDriverActorSystem-akka.actor.default-dispatcher-2] remote.RemoteActorRefProvider$RemotingTerminator (Slf4jLogger.scala:apply$mcV$sp(74)) - Remoting shut down.

我必须按 ctrl-c 来终止 spark-submit 进程。这真是一个奇怪的问题，我不知道如何解决这个问题。如果有任何我应该查看的日志或在这里做不同的事情，请告诉我。

这是 spark-submit 过程的 jstack 输出的 pastebin 链接: http://pastebin.com/Nfnt4XmT

Answer 1

我的 spark 作业代码中的自定义线程池也有同样的问题。我发现 spark-submit 在您的代码中使用自定义非 守护进程线程池时挂起。你可以查看 ThreadUtils.newDaemonCachedThreadPool()了解 spark 开发人员如何创建线程池，或者您可以使用此实用程序，但要小心，因为它们是私有(private)包。