How to do inter-process communication between two instances of the same application?

Question

I was thinking of using WCF, but then the endpoints would collide. What are the other options?

The endpoints will collide because the second instance will be created from the same executable file.

Answer 1

You could use any of the interprocess communication primitives (memory mapped files, message passing, pipes or just standard sockets)... or you could just define the end point dynamically based on the given instance (for example based on the process id).

Answer 2

Whatever IPC mechanism you choose, the basic issue is the same - you will have resource collisions unless you configure the instances individually to use disjoint local resources (though in such a way that each instance pair can connect as required). It makes a difference whether you need just point-to-point (and how the target for a given outbound message is determined), or the ability to broadcast to all active instances.

Seems to me that the answer to this question is really "use the one that best meets your requirements", with a harder followup question on how to configure the instances to make that work.