Where in the page load code is wp-cron triggered?

I just spent way too much time trying to troubleshoot why my wp-cron job wasn't running. It seems, under 4.9.8, the only way to run cron is by calling the wp-cron.php file as a URL.

The docs say though, that it should run on page loads, though I can't locate where. Any help, please?

I just spent way too much time trying to troubleshoot why my wp-cron job wasn't running. It seems, under 4.9.8, the only way to run cron is by calling the wp-cron.php file as a URL.

The docs say though, that it should run on page loads, though I can't locate where. Any help, please?

• wp-cron

Share Improve this question asked Dec 7, 2018 at 8:56 DrazisilDrazisil 10344 bronze badges 2

• 1 Do you have DISABLE_WP_CRON defined in wp-config? – Krzysiek Dróżdż Commented Dec 7, 2018 at 9:02
• I do not, at least not in any way I can locate. – Drazisil Commented Dec 7, 2018 at 12:44

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1 Answer 1

Sorted by: Reset to default 2

The WordPress cron is run by the wp_cron() function, which is hooked to run on the init hook, which runs on every page load.

wp_cron() is defined in wp-includes/cron.php and hooked in wp-includes/default-filters.php.

The wp_cron() function kicks off a wp_remote_post() request to /wp-cron.php. Some server configurations prevent scripts sending a request to the same domain like this however, so as an alternative you can set the ALTERNATE_WP_CRON constant to true. When enabled this redirects the user to the current URL but with ?doing_wp_cron= added to the URL, instead of the post request.