i am working on NodeJs, my question is:
process A runs on computer A, and process B runs on computer B, now i want to broadcast a message to both of them, how can i make it?
You should look into a message queue.
Redis has pub/sub capability and is a common backend component.
You could also consider ZeroMQ depending on what your requirements are.
You're probably looking for dnode, a good very good system of communication between node.js processes.