This was done by floatingghost as part of a bigger commit in Akkoma.
See <37ae047e16/lib/pleroma/application.ex (L83)>.
As explained in <https://ihatebeinga.live/objects/860d23e1-dc64-4b07-8b4d-020b9c56cff6>
> there are so many caches that clearing them all can nuke the supervisor, which by default will become an hero if it gets more than 3 restarts in <5 seconds
And further down the thread
> essentially we've got like 11 caches (37ae047e16/lib/pleroma/application.ex (L165))
> then in test we fetch them all (https://akkoma.dev/AkkomaGang/akkoma/src/branch/develop/test/support/data_case.ex#L50) and call clear on them
> so if this clear fails on any 3 of them, the pleroma supervisor itself will die
How it fails?
> idk maybe cachex dies, maybe :ets does a weird thing
> it doesn't log anything, it just consistently dies during cache clearing so i figured it had to be that
> honestly my best bet is locksmith and queuing
> https://github.com/whitfin/cachex/blob/master/lib/cachex/actions/clear.ex#L26
> clear is thrown into a locksmith transaction
> locksmith says
> >If the process is already in a transactional context, the provided function will be executed immediately. Otherwise the required keys will be locked until the provided function has finished executing.
> so if we get 2 clears too close together, maybe it locks, then doesn't like the next clear?
This is based on me setting one up, but I kept it general with mostly linking to other documentation.
The idea is that to just provide some Pleroma-specific info, maybe give some pointers, and point to the right (external) docs.
It used a timer to sleep.
But time also goes on when doing other things, so depending on hardware, the timings could be off.
I slightly changed the tests so we still test what we functionally want.
Instead of waiting until the cache expires I now have a function to expire the test and use that.
That means we're not testing any more if the cache really expires after a certain amount of time,
but that's the responsability of the dependency imo, so shouldn't be a problem.
I also changed `Pleroma.Web.Endpoint, :http, :ip` to `127.0.0.1` because that's the setting people typically have,
and I see no reason to do it differently.
Especially since it's an exernal ip, which may come over as weird or suspicious to people.
Hélène