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/app/appservice.py | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'synapse/app/appservice.py') diff --git a/synapse/app/appservice.py b/synapse/app/appservice.py index f2540023a7..58f2c9d68c 100644 --- a/synapse/app/appservice.py +++ b/synapse/app/appservice.py @@ -32,10 +32,10 @@ from synapse.replication.tcp.client import ReplicationClientHandler from synapse.server import HomeServer from synapse.storage.engines import create_engine from synapse.util.httpresourcetree import create_resource_tree -from synapse.util.logcontext import LoggingContext, preserve_fn +from synapse.util.logcontext import LoggingContext, run_in_background from synapse.util.manhole import manhole from synapse.util.versionstring import get_version_string -from twisted.internet import reactor +from twisted.internet import reactor, defer from twisted.web.resource import NoResource logger = logging.getLogger("synapse.app.appservice") @@ -112,9 +112,14 @@ class ASReplicationHandler(ReplicationClientHandler): if stream_name == "events": max_stream_id = self.store.get_room_max_stream_ordering() - preserve_fn( - self.appservice_handler.notify_interested_services - )(max_stream_id) + run_in_background(self._notify_app_services, max_stream_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 start(config_options): -- cgit 1.4.1