“Server” to “Server” ZeroMQ communication

Question

I want to build a system that has the following architecture:

+------------------+          +------------------+
| App1. 0mq client | <------> | App2.          


        

Answer 1

Though I am not expert but I once implemented a similar platform.

An additional layer of signaling (REQ/REP) from App2->App1 could do that.

Everytime App2 comes online, a msg should be conveyed to App1.

A separate thread in App1 would be able to receive this msg from App2 anytime.