Improve exception handling for background processes

There were a bunch of places where we fire off a process to happen in the
background, but don't have any exception handling on it - instead relying on
the unhandled error being logged when the relevent deferred gets
garbage-collected.

This is unsatisfactory for a number of reasons:
 - logging on garbage collection is best-effort and may happen some time after
   the error, if at all
 - it can be hard to figure out where the error actually happened.
 - it is logged as a scary CRITICAL error which (a) I always forget to grep for
   and (b) it's not really CRITICAL if a background process we don't care about
   fails.

So this is an attempt to add exception handling to everything we fire off into
the background.
This commit is contained in:
Richard van der Hoff 2018-04-27 11:07:40 +01:00
parent 0ced8b5b47
commit 9255a6cb17
20 changed files with 331 additions and 233 deletions

View file

@ -857,15 +857,25 @@ class EventCreationHandler(object):
@defer.inlineCallbacks
def _notify():
yield run_on_reactor()
self.notifier.on_new_room_event(
event, event_stream_id, max_stream_id,
extra_users=extra_users
)
try:
self.notifier.on_new_room_event(
event, event_stream_id, max_stream_id,
extra_users=extra_users
)
except Exception:
logger.exception("Error notifying about new room event")
preserve_fn(_notify)()
if event.type == EventTypes.Message:
presence = self.hs.get_presence_handler()
# We don't want to block sending messages on any presence code. This
# matters as sometimes presence code can take a while.
preserve_fn(presence.bump_presence_active_time)(requester.user)
run_in_background(self._bump_active_time, requester.user)
@defer.inlineCallbacks
def _bump_active_time(self, user):
try:
presence = self.hs.get_presence_handler()
yield presence.bump_presence_active_time(user)
except Exception:
logger.exception("Error bumping presence active time")