code: private ExecutorService createQueryExecutor() {
  		ThreadFactory threadFactory = new ThreadFactoryBuilder()
  				.setDaemon(true)
  				.setNameFormat("Flink " + getServerName() + " Thread %d")
  				.build();
  		return Executors.newFixedThreadPool(numQueryThreads, threadFactory);
  	}
docs: Creates a thread pool for the query execution.
  @return Thread pool for query execution