From 3cc852d339ad1cdcb0a435c76b44182bdb81dfe9 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Mon, 9 Oct 2017 17:44:42 +0100 Subject: Fancy logformatter to format exceptions better This is a bit of an experimental change at this point; the idea is to see if it helps us track down where our stack overflows are coming from by logging the stack when the exception was caught and turned into a Failure. (We'll also need https://github.com/richvdh/twisted/commit/edf27044200e74680ea67c525768e36dc9d9af2b). If we deploy this, we'll be able to enable it via the log config yaml. --- synapse/util/logformatter.py | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 synapse/util/logformatter.py (limited to 'synapse/util') diff --git a/synapse/util/logformatter.py b/synapse/util/logformatter.py new file mode 100644 index 0000000000..60504162e9 --- /dev/null +++ b/synapse/util/logformatter.py @@ -0,0 +1,43 @@ +# -*- coding: utf-8 -*- +# Copyright 2017 New Vector Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + + +import StringIO +import logging +import traceback + + +class LogFormatter(logging.Formatter): + """Log formatter which gives more detail for exceptions + + This is the same as the standard log formatter, except that when logging + exceptions [typically via log.foo("msg", exc_info=1)], it prints the + sequence that led up to the point at which the exception was caught. + (Normally only stack frames between the point the exception was raised and + where it was caught are logged). + """ + def __init__(self, *args, **kwargs): + super(LogFormatter, self).__init__(*args, **kwargs) + + def formatException(self, ei): + sio = StringIO.StringIO() + sio.write("Capture point (most recent call last):\n") + traceback.print_stack(ei[2].tb_frame.f_back, None, sio) + traceback.print_exception(ei[0], ei[1], ei[2], None, sio) + s = sio.getvalue() + sio.close() + if s[-1:] == "\n": + s = s[:-1] + return s -- cgit 1.4.1