@Override
  public RequestStatusResponse startHost(String hostName, boolean skipFailure) {
    try {
      String hostGroupName = getHostGroupForHost(hostName);
      HostGroup hostGroup = this.blueprint.getHostGroup(hostGroupName);

      // get the set of components that are marked as INSTALL_ONLY
      // for this hostgroup
      Collection<String> installOnlyComponents =
        hostGroup.getComponentNames(ProvisionAction.INSTALL_ONLY);

      return ambariContext.startHost(hostName, ambariContext.getClusterName(getClusterId()), installOnlyComponents, skipFailure);
    } catch (AmbariException e) {
      LOG.error("Cannot get cluster name for clusterId = " + getClusterId(), e);
      throw new RuntimeException(e);
    }
  }
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