Consider a Redis alternative due to the use of the SSPL

[chriscroome]

Summary

A some point in the future it would no doubt make sense to move from the now non-free Redis to an alternative.

The LGPL Redict looks promising, containers are available already.

The BSD Valkey has the support of the Linux Foundation and big cloud capital.

Motivation

At some point Linux distros will stop shipping Redis due to the license change to the SSPL.

Additional context

No response

[lutoma]

Side note: Because the redis definition in the docker-compose just specifies redis:7-alpine, most installations will probably have upgraded to the non-OSS 7.4 version at this point.

That version introduced a new save file format that is incompatible with valkey, so any migration would likely involve rebuilding the redis data now.

[chriscroome]

a new save file format that is incompatible

Another reason to move to a free open source alternative!

[patschi]

I've raised this in our internal mailcow channel to discuss. If anyone happen to know a (easy) migration path, please let us know.

[patschi]

With commit 35a6f81 we have now pinned reddit 7.4.2 (what is what 7-alpine tag represents as of today), so that we at least don't get unexpectedly updated to even "weirder" redis versions.

There are a few possible migrations from redis 7.4 to valkey outlined here: valkey-io/valkey#845 (comment). While not supported by Valkey natively, this could be a way getting to a different redis-alternative...

[sjcrookes]

KeyDB is has been an awesome Redis alternative for us.
Multi-master clustering is also super easy to setup.

https://docs.keydb.dev/
https://github.com/Snapchat/KeyDB