local AMQP messages between MicroServices on same machine

Question

I have developed a modular system based on MicroServices, that can be deployed in one or different machines. Each MicroService actually is a package, and communicate to other MSs sending AMQP messages. In this way each server can specify which MicroService to deploy, installing the relative package. So there is a MicroService that exposes http REST API, and asks reqs to other MicroServices by AMQP messages.

This is an example: each square is a server. Each server can deploy one or MicroServices. So there is one MS listening for http reqs, that sends requests through CloudAMQP channels to other MSs.

                                 +=============+
                                 |  MSs        |
                                 | - AUTHORIZE |
                       amqp      | - LOG       |<---
           +=========+---------->+=============+    |
http:// ==>|  MS     |                              |
           |REST_API |                              | amqp
           +=========+---------->+=============+    |
                       amqp      |  MS         |<---
                                 | - REPORT    |
                                 +=============+

Now, the problem is that also MSs in the same server, exchange amqp messages through the channel, as if they were deployed in different servers. This could be not a problem, but consumes credits on CloudAMQP.

Looking at the example above, a user tries lo login, making a POST on MS_REST_API. This Ms send an amqp message to MS_AUTHORIZE that, in turn, sends an amqp message to MS_LOG to log the event.

Any idea on simulating sending amqp messages, without using CloudAMQP but something local, for MSs deployed on the same machine?

Answer 1

I would advise you against trying to optimize a local-service path unless there is some huge factor you haven't described above. The complexity and opportunity for errors go way up if you try this. Consider, for example, a service that needs to interact with services both local and on other nodes.

If there is a reason to change your approach, I'd recommend looking at something like Apache Qpid Dispatch Router that knows where the applications are and can route them.