Database Maintenance
====================

Xbus stores every envelope in its database, along with all the logs and process
state.

It means the database grows fast, and can get very big (10th of Gb) in a few
weeks if not less.

Therefore purging the data regularly is very important.

The purge is done in 3 steps:

Purging Processes
-----------------

This purge will remove all the process data (its state and its ProcessLogEntries).
The command allow to chose which process will be purged, by their status and by
their last status change date.

The command is:

    `xbusctl ps purge`

For example, to keep the successful processes 1 week, and the failed ones 4 weeks,
run these 2 commands every night:

.. code-block:: bash

    xbusctl ps purge --status-done --status-unchanged-since 168h
    xbusctl ps purge --status-error --status-unchanged-since 672h


Note that the command is interactive and will ask for confirmation.
It can be disabled by adding the `--yes` flag to the command.

Purging Envelopes
-----------------

This purge removes all the envelopes that are not referenced by a process
anymore.

.. code-block:: bash

    xbusctl envelope purge

Purging Logs
------------

This purge removes all the logs older that a given duration.

For example, to remove logs older than 60 days:

.. code-block:: bash

    xbusctl logs purge --older 1344h