How to enable EMS cluster?

Hi There, If I have 3 EMS but I can’t find any about cluster architecture. BTW, I read all support document. Only about load balance configuration. But load balance is not real time architecture. I mean real cluster. For example: EMS origin IP is 1.1.1.1 and edge IP 2.2.2.2 3.3.3.3. The source rtmp push to origin and then edge server will pull stream from origin, or otherwise. So, any guys can be explanation how configuration? Thank you.