Summary

In this chapter, we covered in detail Redis support for the Publish/Subscribe messaging model with Redis's special Pub/Sub mode that clients enter when issuing either a SUBSCRIBE or with glob-style pattern matching variant PSUBSCRIBE Redis commands. When in Pub/Sub mode, other Redis commands cannot be used with the client and the client will monitor one or more channels for any incoming messages. Other clients can push messages to a channel using the PUBLISH Redis command, and all clients subscribing to that channel, either directly or through pattern matching, will receive those messages. To illustrate how to use Redis Pub/Sub with three different programming languages and clients, we constructed a simplified Kanban manufacturing process for constructing Jack-in-the-Box toys for a fictional North Pole company. We then examined two task and messaging frameworks – Celery and RestMQ – that use Redis to implement richer and more robust messaging for client applications, in this case...