What role does Redis serve in Django Channels

Question

Recently I've been using django channels makes its support websocket protocol, I use a microservice way, other components through connection django channels, but I have to write a Consumer class for each connection for receiving and handling, for example class Consumer(AsyncWebsocketConsumer):, which still use the redis, pointed out that this part is the official document as a channel layer storage, so it is as a message queue, the cache or other commonly used functions exist?

I write to find out if there is a Consumer for each connection, and whether I can think of it as acting as a message queue.

However, I have not found relevant materials to support my point of view.

Could you please tell me whether my understanding is correct or not? I sincerely hope that you can provide relevant materials for reference whether it is correct or not.

Answer 1

It depends on how you are using it. The primary purpose of redis in django-channel_layers is to store the necessary information required for different instances of consumers to communicate with one another.

For example, in the tutorial section of channels documentation, it is clear that Redis is used as a storage layer for channel names and group names. These are stored within Redis so that they can be accessed from any consumer instance. If for example, I create a group called 'users' and then add 3 different channel names to it, this information is stored in Redis. Now, whenever I want to send data to the channels in the group I can simply reference the group from my consumer and Django-channels will automatically retrieve the channel names stored under that group in Redis.

On the other hand, if you want to use consumers in a non-conventional way, that is, as background workers then Redis becomes a message queue. That's because when you send a message containing a task to be done by one of the background workers (a consumer that 'consumes' the tasks) those messages have to be stored somewhere so that the background workers can retrieve them as they finish up other tasks.