public static void addGracefulShutDownHook(Runnable shutdownHook, long timeout) {
    addShutdownHook(shutdownHook, GRACEFUL_SHUTDOWN_HOOK_PRIORITY, timeout);
  }
Adds a server's graceful shutdown hook with the highest priority
and the given timeout, so the hook runs earlier than other kinds of hooks.
@param shutdownHook shutdown hook
@param timeout timeout of the shutdownHook
common/src/java/org/apache/hive/common/util/ShutdownHookManager.java