diff --git a/synapse/config/logger.py b/synapse/config/logger.py
index c96e6ef62a..13d6f6a3ea 100644
--- a/synapse/config/logger.py
+++ b/synapse/config/logger.py
@@ -17,6 +17,7 @@ import logging
import logging.config
import os
import sys
+import threading
from string import Template
import yaml
@@ -25,6 +26,7 @@ from twisted.logger import (
ILogObserver,
LogBeginner,
STDLibLogObserver,
+ eventAsText,
globalLogBeginner,
)
@@ -216,8 +218,9 @@ def _setup_stdlib_logging(config, log_config, logBeginner: LogBeginner):
# system.
observer = STDLibLogObserver()
- def _log(event):
+ threadlocal = threading.local()
+ def _log(event):
if "log_text" in event:
if event["log_text"].startswith("DNSDatagramProtocol starting on "):
return
@@ -228,7 +231,25 @@ def _setup_stdlib_logging(config, log_config, logBeginner: LogBeginner):
if event["log_text"].startswith("Timing out client"):
return
- return observer(event)
+ # this is a workaround to make sure we don't get stack overflows when the
+ # logging system raises an error which is written to stderr which is redirected
+ # to the logging system, etc.
+ if getattr(threadlocal, "active", False):
+ # write the text of the event, if any, to the *real* stderr (which may
+ # be redirected to /dev/null, but there's not much we can do)
+ try:
+ event_text = eventAsText(event)
+ print("logging during logging: %s" % event_text, file=sys.__stderr__)
+ except Exception:
+ # gah.
+ pass
+ return
+
+ try:
+ threadlocal.active = True
+ return observer(event)
+ finally:
+ threadlocal.active = False
logBeginner.beginLoggingTo([_log], redirectStandardIO=not config.no_redirect_stdio)
if not config.no_redirect_stdio:
|
