Cron job enables running system functions at desired times.
Some WordPress core functions or plugins, such as image compression or cache preloading, are scheduled to run by default during page loads. If the site has no visitors for a long time, some processes remain unexecuted or wait for new visitors. The problem here is that either the site serves outdated data to the visitor or the site starts using resources to run background processes exactly when they would be needed to serve the visitor.
To work around this, server processes can be scheduled to run with an external wp-cron.php service, which can be scheduled to be called at regular intervals from outside the WordPress installation. This can be done through two different routes in the Plesk control panel, but primarily it should be set up through WP Toolkit:
Behind the three-bar settings button, you should check that the replacement scheduled task has been created and is running. If you want to refine its settings, you can access the scheduled tasks in more detail from this three-bar settings button:
Normally, the scheduled task is started every half hour. If you have a plugin that requires it to run more frequently, you can shorten the time as needed. In cron syntax, you can replace the value at the asterisk position either by listing them separated by commas or you can use the format "*/5" (the content inside quotes without quotes) which means "every fifth". Depending on where you place this, it can be "every fifth minute" or "every fifth hour".
The syntax for scheduling cron jobs is in the format "minute hour day-of-month month day-of-week".
For example, if you want to run a cron job every Monday at 04:35, the correct format is 35 4 * * 1. The asterisk means "any value" in this context, i.e., every day of the month and every month.
Days of the week are indicated as 0 -> Sunday, 1-> Monday and so on.
In the example image, Cron is executed twice an hour, at xx:14 and xx:44 every hour. It can be set to run even every minute, but usually there is no sensible reason for that.
So we do not recommend running cron jobs every minute - for general server performance, please try to limit Cron execution frequency on shared servers.
