void cleanupEngineHost(MonitorEngine engine) throws ResourceException {
   Host host = engine.getHost();
   // TODO 如果是默认引擎所在的主机,其还与监控服务器,以及其他应用存在RunAt关系这些关系还没清除掉
   //  最终逻辑,应该是监控引擎删除/尝试删除所依赖的组件(存在server的情况下删除不掉)
   //  而后删除 引擎 + 主机的 RunAt关系
   //  尝试删除主机(但是由于未能将server, mysql, redis等组件删除,所以主机存在关系,无法删除)
   if (host != null) {
     LinkService linkService = serviceLocator.locateLinkService(LinkType.RunOn.name());
     if (linkService == null)
       throw new IllegalStateException(
           "Can't find link service for link type = " + LinkType.RunOn);
     linkService.unlink(engine, host, LinkType.RunOn);
     //noinspection unchecked
     HostService<Host> hostService = (HostService<Host>) serviceLocator.locate(host.getType());
     try {
       hostService.delete(host);
     } catch (ResourceException e) {
       logger.warn("Can't delete the engine host, because of there are some legacy links ", e);
     }
   }
 }