Distributed system design using only C

Question

I have the work of implementing a distributed system of nodes (like p2p nodes) each of these nodes (lets say A,B,C and D) perform certain functions and need to interact with

Answer 1

The secret to prevent blocking is your end points must all be written as servers with threads for "protocol" processing that are separate from the threads for data processing.

As for line protocol, I've become enamored with JSON for line protocol. It is human readable. It is streamable without need for length bytes! It is easily extensible and mostly immune to protocol version change.