Movable Type has a scheduled tasks system that is used to perform certain tasks on scheduled basis. Built-in tasks include expiring junk (spam) trackbacks and comments, and posting entries that were scheduled to to published at a certain date / time. Movable Type plugins can also use scheduled tasks, as some of my plugins do (including Visitor Stats Pro, Ajax Rating Pro, and Blog Janitor). One of the benefit of scheduled tasks is to improvement performance and user experience -- resource intensive functions can be run without making admins, authors, and commenters wait while they complete.
Triggering Scheduled Tasks
Scheduled task will only run when they are triggered. This is important. Even if a task is scheduled to run every hour, it scheduled tasks don't get triggered, the task will never run. By default Movable Type will trigger scheduled tasks in the following cases:
- You receive a junk (spam) comment or trackback. Note: this will only trigger the 'Junk expiration' task - it won't trigger plugin tasks.
- You view or download an XML "activity feed" (These feeds show up on with orange feed links on many screens of the admin MT interface, including entry and comment listings, and activity log).
- When the run-periodic-tasks script (found in the 'tools' directory of MT) is run via the command line or via cron.
