Hello, I saw a few tickets and some mailing list messages similar to this question, but never saw a definitive answer. How do I go about using a different logger when I am using twistd? I have a file that defines the application object and I tried the following code in hopes that I could make the logger have max rotated logs set to a smaller number: logfile =Â LogFile(LOG_FILE, LOG_DIRECTORY, LOG_SIZE, maxRotatedFiles=MAX_LOGS) application.setComponent(ILogObserver, FileLogObserver(logfile)) but I get an assertion error coming up: Traceback (most recent call last): File "/usr/bin/twistd", line 21, in <module> run() File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/scripts/twistd.py", line 27, in run app.run(runApp, ServerOptions) File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/application/app.py", line 693, in run runApp(config) File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/scripts/twistd.py", line 23, in runApp _SomeApplicationRunner(config).run() File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/application/app.py", line 421, in run self.logger.start(self.application) File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/application/app.py", line 249, in start log.startLoggingWithObserver(self._observer) File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/python/log.py", line 592, in startLoggingWithObserver addObserver(observer) File "/Library/Python/2.6/site-packages/Twisted-9.0.0-py2.6-macosx-10.6-universal.egg/twisted/python/log.py", line 253, in addObserver assert callable(other) AssertionError