@Override
  public Map<Long, ConfigGroup> getConfigGroupsByHostname(String hostname)
    throws AmbariException {
    Map<Long, ConfigGroup> configGroups = new HashMap<>();

    for (Entry<Long, ConfigGroup> groupEntry : clusterConfigGroups.entrySet()) {
      Long id = groupEntry.getKey();
      ConfigGroup group = groupEntry.getValue();
      for (Host host : group.getHosts().values()) {
        if (StringUtils.equals(hostname, host.getHostName())) {
          configGroups.put(id, group);
          break;
        }
      }
    }
    return configGroups;
  }
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