In what circumstances can ZeroMQ sockets fall or fail to deliver messages?

Question

Is there some specification or other explanation that describes common cases where you can expect that a message sent on a ZeroMQ socket will not be received by (all) listening processes for each type of connection?

For example, I have an experimental program that basically assumes that all PUB socket subscribers will receive all messages sent to this socket (after establishing the initialization handshake). I would like to understand cases where this assumption may be false. Thanks, and sorry if this has already been asked.

Answer 1

The diagram in this image is a good guide for when zmq messages sockets drop messages: https://raw.github.com/imatix/zguide/master/images/fig25.png

For more information, you can read http://zguide.zeromq.org/py:all#Missing-Message-Problem-Solver