@Override
  @Transactional
  public void addServiceComponentHosts(Collection<ServiceComponentHost> serviceComponentHosts) throws AmbariException {
    for (ServiceComponentHost serviceComponentHost : serviceComponentHosts) {
      Service service = getService(serviceComponentHost.getServiceName());
      ServiceComponent serviceComponent = service.getServiceComponent(serviceComponentHost.getServiceComponentName());
      serviceComponent.addServiceComponentHost(serviceComponentHost);
    }
  }
Make sure we load all the service host components.
We need this for live status checks.
ambari-server/src/main/java/org/apache/ambari/server/state/cluster/ClusterImpl.java