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?
Current FedSocket implementation has a bunch of problems. It doesn't
have proper error handling (in case of an error the server just doesn't
respond until the connection is closed, while the client doesn't match
any error messages and just assumes there has been an error after 15s)
and the code is full of bad descisions (see: fetch registry which uses
uuids for no reason and waits for a response by recursively querying a
ets table until the value changes, or double JSON encoding).
Sometime ago I almost completed rewriting fedsockets from scrach to
adress these issues. However, while doing so, I realized that fedsockets
are just too overkill for what they were trying to accomplish, which is
reduce the overhead of federation by not signing every message.
This could be done without reimplementing failure states and endpoint
logic we already have with HTTP by, for example, using TLS cert auth,
or switching to a more performant signature algorithm. I opened
https://git.pleroma.social/pleroma/pleroma/-/issues/2262 for further
discussion on alternatives to fedsockets.
From discussions I had with other Pleroma developers it seems like they
would approve the descision to remove them as well,
therefore I am submitting this patch.
Added ffmpeg/imagemagick checks to launch checks (if media preview proxy is enabled). Added documentation on installing optional media / graphics packages (imagemagick, ffmpeg, exiftool).
This patch refactors gun pooling to use Elixir process registry and
simplifies adapter option insertion.
Having the pool use process registry instead of a GenServer has a number of advantages:
- Simpler code: the initial implementation adds about half the lines of code it deletes
- Concurrency: unlike a GenServer, ETS-based registry can handle multiple checkout/checkin
requests at the same time
- Precise and easy idle connection clousure: current proposal for closing idle connections in
the GenServer-based pool needs to filter through all connections once a minute and compare their
last active time with closing time. With Elixir process registry this can be done
by just using `Process.send_after`/`Process.cancel_timer` in the worker process.
- Lower memory footprint: In my tests `gun-memory-leak` branch uses about 290mb on peak load (250 connections)
and 235mb on idle (5-10 connections). Registry-based pool uses 210mb on idle and 240mb on peak load
Previously, in-db configuration only worked when `warnings_as_errors`
was disabled because re-compiling scrubbers on application restart
created a warning about module conflicts. This patch fixes that
by enabling `ignore_module_conflict` option of the compiler at runtime,
and enables `warnings_as_errors` in prod since there is no reason
to keep it disabled anymore.
