IP.Board provides options (System Settings > Advanced > Log Pruning) to enable / disable pruning various logs such as spider logs, database error logs, spam logs etc.

The only issue some administrators may have is that thirty days may be too long, or in some rare cases not enough but again not enough to justify not pruning them.

A simple tweak is possible to adjust the pruning schedule.

Connect via FTP or your hosts file manager and open admin/applications/core/tasks/logprune.php

Around line 34, find...

protected $deleteTime = 2592000;

Replace that line with one of the following, depending on what you require.

14 days

protected $deleteTime = 1209600;

7 days

protected $deleteTime = 604800;

3 days

protected $deleteTime = 259200;

Save the change. The settings description will still indicate 30 days but the actual pruning will take place at the days interval you have specified. , remember this change will effect them all so you may wish to disable any pruning you do not want to occur at that interval.