From 9255a6cb17716c022ebae1dbe9c142b78ca86ea7 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 27 Apr 2018 11:07:40 +0100 Subject: 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. --- synapse/notifier.py | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'synapse/notifier.py') diff --git a/synapse/notifier.py b/synapse/notifier.py index 0e40a4aad6..939723a404 100644 --- a/synapse/notifier.py +++ b/synapse/notifier.py @@ -21,7 +21,7 @@ from synapse.handlers.presence import format_user_presence_state from synapse.util import DeferredTimedOutError from synapse.util.logutils import log_function from synapse.util.async import ObservableDeferred -from synapse.util.logcontext import PreserveLoggingContext, preserve_fn +from synapse.util.logcontext import PreserveLoggingContext, run_in_background from synapse.util.metrics import Measure from synapse.types import StreamToken from synapse.visibility import filter_events_for_client @@ -251,9 +251,7 @@ class Notifier(object): def _on_new_room_event(self, event, room_stream_id, extra_users=[]): """Notify any user streams that are interested in this room event""" # poke any interested application service. - preserve_fn(self.appservice_handler.notify_interested_services)( - room_stream_id - ) + run_in_background(self._notify_app_services, room_stream_id) if self.federation_sender: self.federation_sender.notify_new_events(room_stream_id) @@ -267,6 +265,13 @@ class Notifier(object): rooms=[event.room_id], ) + @defer.inlineCallbacks + def _notify_app_services(self, room_stream_id): + try: + yield self.appservice_handler.notify_interested_services(room_stream_id) + except Exception: + logger.exception("Error notifying application services of event") + def on_new_event(self, stream_key, new_token, users=[], rooms=[]): """ Used to inform listeners that something has happend event wise. -- cgit 1.5.1