11.4. Summary

This was another fairly long chapter! We started off using RabbitMQ to send and receive messages between Clojure applications. We then wrote a convenient abstraction (message-seq) to deal with the fact that most receiving programs process incoming messages in a loop. This made it ideal to treat the stream of messages being delivered by RabbitMQ as a sequence, thereby allowing programs to unleash the full power of the Clojure sequence library on such a message stream.

After we got the basics out of the way, we implemented a little framework to write distributed Clojure applications in an easy and intuitive manner. This framework made it simple to write applications that made use of multiple JVM processes running across machines. Over the course of the chapter, we added features to this framework, and we brought it to a point where it could form the basis of something useable in the real world. And the whole thing clocked in at fewer than 200 lines of code.