@Subscribe
  public void onClusterConfigFinishedEvent(ClusterConfigFinishedEvent event) {
    ManagedThreadPoolExecutor taskExecutor = topologyTaskExecutorServiceMap.get(event.getClusterId());
    if (taskExecutor == null) {
      LOG.error("Can't find executor service taskQueue not found for cluster: {} ", event.getClusterName());
    } else {
      LOG.info("Starting topology task ExecutorService for cluster: {}", event.getClusterName());
      taskExecutor.start();
    }
  }
The Kerberos Client component is unnecessarily installed via Blueprints when kerberos-env/kdc-type is "none".
The Blueprint TopologyManager should only force the Kerberos client to be installed if Kerberos is enabled
and kerberos_env/kdc_type is not "none" or when kerberos_env/manage_identities is true.

@param topology the Cluster Topology which provides the topology's Configuration object.
@return true if kerberos_env/kdc_type is not "none" or when kerberos_env/manage_identities is true
ambari-server/src/main/java/org/apache/ambari/server/topology/TopologyManager.java