WP-CRON is used by plugins and certain Wordpress core functions to schedule events such as backups, publishing scheduled posts or running scheduled virus scans.
WP-CRON is called to check for any scheduled tasks that is due to be run each time a site is being accessed even if the page being accessed does not require any scheduled tasks.
This in turn results in large number of WP-CRON requests made to the server when the site is experiencing high traffic which can cause a simple website to be resource intensive.
To resolve this, we would disable WP-CRON and use the system cron instead so that WP-CRON is not executed.
How to disable WP-CRON
Go to your WordPress root folder and open the wp-config.php file.
You can do so from the FTP or from the File Manage of your respective control panel.
Insert the following line of code directly above the line ‘/* That’s all, stop editing! Happy blogging. */’
Save the file.