The base tasks

The Scheduler comes by default with several tasks:

  • Caching framework garbage collection : some cache backends do not have an automatic garbage collection process. For these it is useful to run this Scheduler task to regularly free some space.
  • Fileadmin garbage collection : empties _recycler_ folders in the fileadmin.
  • Table garbage collection : cleans up old records from any table in the database. See related section below for more information on configuration.

Table garbage collection task

The table garbage collection task can take a more elaborate configuration which is detailed below.

The task can be registered to clean up a particular table, in which case you simply choose the table and the minimum age of the records to delete from the task configuration screen.

Table Garbage Collection task configuration

Configuring the table garbage collection task

It's also possible to clean up all configured table by checking the "Clean all available tables" box. The configuration for the tables to clean up is stored in $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['scheduler']['tasks']['tx_scheduler_TableGarbageCollection']['options']['tables']. The syntax is the following:

  • option expireField can be used to point to a table field containing an expiry timestamp. This timestamp will then be used to decide whether a record has expired or not. If its timestamp is in the past, the record will be deleted.
  • if a table has no expiry field, one can use a combination of a date field and an expiry period to decide which records should be deleted. The corresponding options are dateField and expirePeriod. The expiry period is expressed in days.

Example

$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['scheduler']['tasks']['tx_scheduler_TableGarbageCollection']['options']['tables'] = array(
        'tx_realurl_errorlog' => array(
                'dateField' => 'tstamp',
                'expirePeriod' => '180'
        ),
        'tx_realurl_uniqalias' => array(
                'expireField' => 'expire'
        )
);

The first part of the configuration indicates that records older than 180 days should be removed from table tx_realurl_errorlog , based on the timestamp field called "tstamp". The second part indicates that old records should be removed from table tx_realurl_uniqalias directly based on the field "expire" which contains expiration dates for each record.

Other tasks

More tasks are provided by system extensions, such as the Extension Manager, which defines one for updating the available extensions list.

The Scheduler also comes with two sample tasks. As explained at the beginning of this chapter, they can be turned off from the extension's configuration options.

The "test" task just sends a mail to a given e-mail address. The "sleep" task goes to sleep for a given number of seconds. They are not very useful in the everyday running of a web site, but they are nice to have when testing stuff. If you want to make sure that your Scheduler installation is complete, register an instance of the "test" task and wait for the mail to arrive (if it doesn't arrive, check in the Log if the task has indeed run).

The "sleep" task is mostly useful for testing parallel executions (by creating an instance of the task that goes to sleep for a longer time than the frequency).

The base tasks are also there to serve as examples for task developers (see "Developer's Guide" below).