Symfony version(s) affected: all

Description
On Symfony Slack some people were discussing about Messenger and other alternatives. A person said:

[I had] bad experience using redis transport in production (on 2 different projects): memory consumption was (way) too high. Couldn’t figure out what was the root cause of this, but it was faster to migrate [to a Messenger alternative].

And another added that:

I run a redis docker image with 500 MB memory, and it will stop working if memory is full

How to reproduce
No specific details were given about how to reproduce, so I guess you only need to use Messenger + Redis to see the excessive memory consumption.