Warning: currently only works with mysql
A simple management command that can delete expired sessions from large session tables without killing the site.
The main use case is if you have a live application with millions of stale sessions in the database. Runnung the
python manage.py cleanup will potentially lock your database for hours, essentially killing your site.
django-graceful-session-cleanup you can gradually delete all the sessions.
To achieve this it will always only delete a small amount of the expired sessions per query and then sleep for a few seconds. There are commandline options to control interval, sleep time and amount of sessions to delete per interval.
install the package:
pip install django-graceful-session-cleanup
add it to
INSTALLED_APPS = [ .... 'graceful_session_cleanup', ]
run the management command:
python manage.py graceful_session_cleanup
There are a few options you can use:
python manage.py graceful_session_cleanup --sleep-seconds 9 --delete-count 1000 --iteration-count 200
This will delete
1000 expired session entries, wait for
5 seconds so other processes can use the
database and then repeat this
200 times. Depending on database load (assuming deleting takes
(9s + 1s) * 200 = 2000s.
there is help on the commandline:
$ python manage.py help graceful_session_cleanup Usage: django graceful_session_cleanup [options] Can be run as a cronjob or directly to clean out old data from the database (only expired sessions at the moment). Does this in a live db friendly way by never hogging the connection too long. Options: -v VERBOSITY, --verbosity=VERBOSITY Verbosity level; 0=minimal output, 1=normal output, 2=all output --settings=SETTINGS The Python path to a settings module, e.g. "myproject.settings.main". If this isn't provided, the DJANGO_SETTINGS_MODULE environment variable will be used. --pythonpath=PYTHONPATH A directory to add to the Python path, e.g. "/home/djangoprojects/myproject". --traceback Print traceback on exception -s SLEEP_SECONDS, --sleep-seconds=SLEEP_SECONDS How long to sleep between each delete operation. -c DELETE_COUNT, --delete-count=DELETE_COUNT How many expired sessions to delete per iteration. -i ITERATION_COUNT, --iteration-count=ITERATION_COUNT How many iterations to run. --version show program's version number and exit -h, --help show this help message and exit