The request/response communication pattern involves two peers. This pattern is a bidirectional communication: a client asks for something from a service, and the service answers to this query. The following figure shows how this pattern works:
Figure 12.8: The request/response communication pattern
This communication pattern is probably the most used of all the available patterns. This is probably because it is the pattern used for human communication. Just like publish/subscribe, this pattern can be used on all kinds of communication: intra-process, inter-process, and on network links with Remote Procedure Calls (RPCs):
