What does Discourse use Redis for?

[sethherr]

This is a little bit of a stale post, but I figured I should expand on this reply since I ran into this when searching for some other Discourse Redis stuff.

Here’s an answer from a team member to what other than Sidekiq does Discourse use redis for:

Minimum Redis Version

Quite a lot actually. We use Redis backend in the https://github.com/discourse/message_bus gem for live page updates, for the Rails cache, for the distributed rate limit, for our semaphore system, etc.