Bolt Internals / Task Scheduler (cron)

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Bolt comes with a built-in, extensible, task scheduler. This task scheduler relies on the operatings systems underlying scheduler (e.g. cron) for execution.

Currently the following jobs are run internally by Bolt's task scheduler:

• Cache clearing - A weekly job to clear Bolt's internal cache
• Log trimming - A weekly job to trim Bolt's log database

Set up¶

Under UNIX/Linux style operating systems you will need to create a crontab entry to execute Bolt's command line interface 'nut', located in Bolt's app/ directory.

The format should look something like:

# min hour day month weekday command
0   */1    *    *    *       /var/www/my_site/app/nut cron

Where you change /var/www/my_site to be the correct path to your Bolt installation.

Then in config.yml you need to set the cron_hour parameter. The parameter takes an integer between 0 and 23, representitive of the hour of the day you want the daily, weekly, monthly and yearly tasks to execute at. By default is set to 03:00 am.

cron_hour: 3

Command Line¶

The task schedulers job intervals can be run on demand using nut from the command line, e.g. To run the hourly tasks:

./app/nut cron --run=cron.Hourly

The parameter passed to --run can be any of the following:

• cron.Hourly
• cron.Daily
• cron.Weekly
• cron.Monthly
• cron.Yearly

Extending¶

Bolt's task scheduler can be interfaced in extensions by setting a listener. To create a listener you need to something similar in your extension:

use Bolt\Events\CronEvents;

class Extension extends \Bolt\BaseExtension
{
    public function initialize()
    {
        $this->app['dispatcher']->addListener(CronEvents::CRON_INTERVAL, array($this, 'myJobCallbackMethod'));
    }
}

CRON_INTERVAL should be replaced with one of the following:

• CRON_HOURLY
• CRON_DAILY
• CRON_WEEKLY
• CRON_MONTHLY
• CRON_YEARLY

This will invoke your extension class method myJobCallbackMethod at the defined interval and time.