ZeroMQ and its bindings are well-proven, extremely well written, and the ZeroMQ guide is a work of art. That said, the bindings are not created equal. We've seen some unreliability with the Java package even though the official C/C++ and Python bindings work perfectly (the Go package too).

The thin layer on TCP leaves a lot of things to be desired. Such as knowing if the other end has disappeared and won't ever come back.

Last time I used ZeroMQ was ~7 months ago at my previous job, so maybe things have changed since then, but having to write hacks to see if the other side is still there or not is absolutely terrible.

Also, the Python bindings did not like fork() without exec, which yes is bad and all, but is still something that is done every so often in real world large programs.

I second this recommendation. I use MsgPack over ZeroMQ with a custom RPC protocol. Protobuf, Capn Proto, Flatbuffers are good serialization mechanisms as well. Can't wait until the new Socket Types are out of draft stage.

I believe GRPC is pluggable so if one wanted to invest time in building a GRPC ZeroMQ Transport then that is a feasible route. GRPC bring really good RPC mechanisms to the table.

especially when you use the router pattern on server side in order to have multiple sessions on the same socket.

Surprised article didn’t include this in its comparison. Seems an obvious contender.