16.2. Database cleaning

The Compute service includes an administrative tool, nova-manage, that you can use to perform deployment, upgrade, clean-up, and maintenance-related tasks, such as applying database schemas, performing online data migrations during an upgrade, and managing and cleaning up the database.

Director automates the following database management tasks on the overcloud by using cron:

  • Archives deleted instance records by moving the deleted rows from the production tables to shadow tables.
  • Purges deleted rows from the shadow tables after archiving is complete.

16.2.1. Configuring database management

The cron jobs use default settings to perform database management tasks. By default, the database archiving cron jobs run daily at 00:01, and the database purging cron jobs run daily at 05:00, both with a jitter between 0 and 3600 seconds. You can modify these settings as required by using heat parameters.


  1. Open your Compute environment file.
  2. Add the heat parameter that controls the cron job that you want to add or modify. For example, to purge the shadow tables immediately after they are archived, set the following parameter to "True":

      NovaCronArchiveDeleteRowsPurge: True

    For a complete list of the heat parameters to manage database cron jobs, see Configuration options for the Compute service automated database management.

  3. Save the updates to your Compute environment file.
  4. Add your Compute environment file to the stack with your other environment files and deploy the overcloud:

    (undercloud)$ openstack overcloud deploy --templates \
      -e [your environment files] \
      -e /home/stack/templates/<compute_environment_file>.yaml