> Have a read of the zguide, there should be plenty information of > various failover patterns: http://zguide.zeromq.org/
Yep, read that. I'm happy with my REQ/REP exchanger pattern now that I have a better grasp of the underlying behaviour. As I mentioned previously the docs on REQ/REP state: "If no services are available, then any send operation on the socket shall block until at least one service becomes available." but the send() doesn't block in this situation. As you said earlier the message is queued and sent async with send() returning to the caller. I also mis-interpreted the docs to imply that when "at least one service becomes available" that any queued messages would go to that service, but that's not the case as the round-robin decision is only made once on the call to send() - not during the async sending process. Anyhoo, it's all good now that I know better. Mark. _______________________________________________ zeromq-dev mailing list zeromq-dev@lists.zeromq.org https://lists.zeromq.org/mailman/listinfo/zeromq-dev