@Override
  public boolean isRunning() {
    if (gfManagerAgent == null) {
      return false;
    }
    // is there a better way??
    // this.gfManagerAgent.isConnected() ... this.gfManagerAgent.isListening()

    return isAnyMemberRunning();
  }
Returns true if any members of this system are currently running.
geode-core/src/main/java/org/apache/geode/admin/internal/AdminDistributedSystemImpl.java