public void shutdown() {
    this.delayedSubmitTimer.shutdownNow();
    for (Entry<String, Executor> entry : this.executorMap.entrySet()) {
      List<Runnable> wasRunning = entry.getValue().threadPoolExecutor.shutdownNow();
      if (!wasRunning.isEmpty()) {
        LOG.info(entry.getValue() + " had " + wasRunning + " on shutdown");
      }
    }
    this.executorMap.clear();
  }
Start an executor service with a given name. If there was a service already started with the
same name, this throws a RuntimeException.
@param config Configuration to use for the executor.
hbase-server/src/main/java/org/apache/hadoop/hbase/executor/ExecutorService.java