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/rest/media/v1/storage_provider.py | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'synapse/rest/media') diff --git a/synapse/rest/media/v1/storage_provider.py b/synapse/rest/media/v1/storage_provider.py index c188192f2b..0252afd9d3 100644 --- a/synapse/rest/media/v1/storage_provider.py +++ b/synapse/rest/media/v1/storage_provider.py @@ -18,7 +18,7 @@ from twisted.internet import defer, threads from .media_storage import FileResponder from synapse.config._base import Config -from synapse.util.logcontext import preserve_fn +from synapse.util.logcontext import run_in_background import logging import os @@ -87,7 +87,12 @@ class StorageProviderWrapper(StorageProvider): return self.backend.store_file(path, file_info) else: # TODO: Handle errors. - preserve_fn(self.backend.store_file)(path, file_info) + def store(): + try: + return self.backend.store_file(path, file_info) + except Exception: + logger.exception("Error storing file") + run_in_background(store) return defer.succeed(None) def fetch(self, path, file_info): -- cgit 1.4.1