Question

I have a simple server written in C. It’s main purpose is to communicate with some business partners over a proprietary protocol. For that reason and a few others, it must be written in C. I have a number of other processes, however, written in other languages (e.g. Python) that must communicate with the server (locally, on the same Linux server).

What are the best options for cross-language IPC in this scenario? Specifically, I think I have a handle on transport technologies: Unix domain sockets, named pipes, shared memory, ZeroMQ (Crossroads). I’m more interested in the best way to implement the protocol, in order to keep the C code small and maintainable, while still allowing communication from other languages.

Edit: there seems to be some confusion. I’m not interested in discussion of pros/cons of domain sockets, shared memory et. al. I am interested in msgpack (thanks unwind), and other technologies/approaches for implementing the wire protocol.

Answer 1

It’s hard to optimize (=select the “best”) when the requirements are unknown. You do state that your goal is to keep the C code “small and maintainable”, which seems to imply that you should look for a library. Perhaps msgpack over a local socket?

Also, your basic premise that the server must be written in C because you have a proprietary protocol seems … weird, at least.