private void ensureInitialized() {
    if (!isInitialized) {
      synchronized (initializationLock) {
        if (!isInitialized) {
          replayRequests(persistedState.getAllRequests());
          // ensure KERBEROS_CLIENT is present in each hostgroup even if it's not in original BP
          for(ClusterTopology clusterTopology : clusterTopologyMap.values()) {
            if (clusterTopology.isClusterKerberosEnabled() && isKerberosClientInstallAllowed(clusterTopology)) {
              addKerberosClient(clusterTopology);
            }
          }
          isInitialized = true;
        }

      }
    }
  }
Flag to show whether blueprint is already finished or not. It is used for shortcuts.
ambari-server/src/main/java/org/apache/ambari/server/topology/TopologyManager.java