zulip/zerver/worker
Tim Abbott 783a77c532 queue processors: Flush per-request caches after each item.
Several of our queues are capable of doing work that includes
rendering markdown (outgoing_webhook, embedded_bots, embed_links, and
email_mirror).  As a result, it's essential that these don't cache
per-request data (specifically, realm filters) longer than they
should, making editing/deleting linkifiers potentially use old
settings until the relevant process was restarted.

Flushing these caches is extremely cheap (just clearing two
dictionaries) and thus is reasonable to do after every queue event,
rather than trying to do it only the ~1/3 of queues that specifically
do markdown processing.  We do the same in our middleware for
reset_queries.

It's not worth writing a test for this because it's very difficult to
create the test setup situation for this bug with a single test worker
process; one needs to edit the linkifier configuration in a different
process than the one sending the message in order to see the bug.

This was a much larger visible bug on Zulip 2.1.x, where the presence
of the message_sender queue meant that this would apply to messages
sent via a browser.

Fixes #14095.
2020-03-03 15:29:11 -08:00
..
__init__.py
queue_processors.py queue processors: Flush per-request caches after each item. 2020-03-03 15:29:11 -08:00