[YARN-5809] AsyncDispatcher possibly invokes multiple shutdown thread when handling exception

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.9.0, 3.0.0-alpha2
• Hadoop Flags: Reviewed
• Assignee: Jian He
• Reporter: Jian He
• Created: 31/Oct/16 21:32
• Updated: 31/Oct/16 23:42
• Resolved: 31/Oct/16 23:09

Description

below code when handling exceptions: it is possible to launch multiple shutdown threads if there are events left in the queue that caused to throw exceptions.

    } catch (Throwable t) {
      //TODO Maybe log the state of the queue
      LOG.fatal("Error in dispatcher thread", t);
      // If serviceStop is called, we should exit this thread gracefully.
      if (exitOnDispatchException
          && (ShutdownHookManager.get().isShutdownInProgress()) == false
          && stopped == false) {
        Thread shutDownThread = new Thread(createShutDownThread());
        shutDownThread.setName("AsyncDispatcher ShutDown handler");
        shutDownThread.start();
      }
    }