@Override
  public Set<String> getServiceHosts() {
    Set<String> hostNames = new HashSet<>();
    for (ServiceComponent serviceComponent : getServiceComponents().values()) {
      hostNames.addAll(serviceComponent.getServiceComponentsHosts());
    }
    return hostNames;
  }
Refresh Service info due to current stack
@throws AmbariException
ambari-server/src/main/java/org/apache/ambari/server/state/ServiceImpl.java