private void registerRackInfo(HostGroupInfo hostGroupInfo, String host) {
    synchronized (hostGroupInfoMap) {
      HostGroupInfo cachedHGI = hostGroupInfoMap.get(hostGroupInfo.getHostGroupName());
      if (null != cachedHGI) {
        cachedHGI.addHostRackInfo(host, hostGroupInfo.getHostRackInfo().get(host));
      }
    }
  }
Static convenience function to determine if Yarn ResourceManager HA is enabled
@param configProperties configuration properties for this cluster
@return true if Yarn ResourceManager HA is enabled
        false if Yarn ResourceManager HA is not enabled
ambari-server/src/main/java/org/apache/ambari/server/topology/ClusterTopologyImpl.java