Free as in freedom rsyslog mysql housekeeping script.
The current change log can be found here.
The current documentation can be found here.
It all started with this question >>How to automatically delete database contents?<<.
The script removes entries older than <configured value> days from the database table Syslog.SystemEvents.
The script comes with an install- and an uninstall routine.
All configurable values are configured in project_path/data/local_configuration.sh.