protected void stop() throws Exception {
    accepted.close().awaitUninterruptibly(10, TimeUnit.SECONDS);
    if (bossGroup != null) {
      bossGroup.shutdownGracefully();
    }
    if (workerGroup != null) {
      workerGroup.shutdownGracefully();
    }
    destroyPipeline();

    if (dirWatcher != null) {
      dirWatcher.stop();
    }
  }
Unregister a specific dag

This method and registerDag must be synchronized externally to prevent races in shuffle token registration/unregistration

@param dir
@param applicationIdString
@param dagIdentifier
llap-server/src/java/org/apache/hadoop/hive/llap/shufflehandler/ShuffleHandler.java