void stop() throws IOException {
    shutdown.set(true);
    if (watcherFuture != null) {
      watcherFuture.cancel(true);
    }
    if (expirerFuture != null) {
      expirerFuture.cancel(true);
    }
    watchService.close();
    watcherExecutorService.shutdownNow();
    expirerExecutorService.shutdownNow();
  }
Invoke when a pathIdentifier has been found, or is no longer of interest
@param pathIdentifier
llap-server/src/java/org/apache/hadoop/hive/llap/shufflehandler/DirWatcher.java