public boolean isSupportDeleteViaUI() {
    if (null != supportDeleteViaUIField) {
      return supportDeleteViaUIField.booleanValue();
    }
    // If set to null and has a parent, then the value would have already been resolved and set.
    // Otherwise, return the default value (true).
    return supportDeleteViaUIInternal;
  }
Used to determine if rolling restart is supported
ambari-server/src/main/java/org/apache/ambari/server/state/ServiceInfo.java