TimedRotatingFileHandler() isn't rotating at midnight?

[Chris Shenton]

I set this up 3 days ago and have not seen any of the logs I've
created this way being rotated. I expected them to rotate every
midnight. I'm calling the code that uses this logger many times, each
a separate run, if that matters.

Am I doing something stupid? I can't find anything on google and don't
see anything in the code that would prevent rotating.

Thanks.

import logging, logging.handlers
logging.getLogger().setLevel(logging.DEBUG) # override default of WARNING

logfile = logging.handlers.TimedRotatingFileHandler(filename, 'midnight', 1, backupCount=14)
logfile.setLevel(logging.DEBUG)
logfile.setFormatter(logging.Formatter('%(asctime)s %(levelname)-8s %(module)s: %(message)s'))
logging.getLogger().addHandler(logfile)

 

[Vinay Sajip]

I set this up 3 days ago and have not seen any of the logs I've
created this way being rotated. I expected them to rotate every
midnight. I'm calling the code that uses this logger many times, each
a separate run, if that matters.

It might. I assume you have a long-running process which runs past
midnight - that's the scenario that TimedRotatingFileHandler is meant
for. Can you post a complete minimal example which shows the problem?

Am I doing something stupid? I can't find anything on google and don't
see anything in the code that would prevent rotating.

Rotating should happen when the logging process creates the handler
before midnight and makes a logging call destined for that handler
after midnight.

Regards,

Vinay Sajip

 

[Chris Shenton]

It might. I assume you have a long-running process which runs past
midnight - that's the scenario that TimedRotatingFileHandler is meant
for. Can you post a complete minimal example which shows the problem?

Rotating should happen when the logging process creates the handler
before midnight and makes a logging call destined for that handler
after midnight.

Ah, then maybe I'm expecting the wrong thing. The python code is
invoked from cron every 10 minutes or so, it's not long-running.
Each time it opens the same log file. Sounds like this isn't going to
do what I want.

Thanks for the clarification.

 

[skip]

Chris> Ah, then maybe I'm expecting the wrong thing. The python code is
Chris> invoked from cron every 10 minutes or so, it's not long-running.
Chris> Each time it opens the same log file. Sounds like this isn't
Chris> going to do what I want.

Right. Check out the logrotate facility on your system.

Skip

 

[Vinay Sajip]

Right. Check out the logrotate facility on your system.

This can be used together with the WatchedFileHandler recently checked
into SVN trunk - this (Unix/Linux-only) handler checks to see if the
dev or inode have changed, and if they have (because of rotation by
e.g. logrotate), reopens the file before writing to it.

Regards,

Vinay Sajip