High CPU from WordPress site hosted on Plesk: Too many php-fpm processes

Symptoms

• CPU consumption is very high (up to 100%) in a Plesk server

• Many PHP-FPM processes are created by the system user of a WordPress site

• The site's PHP handler's error log (e.g. /var/log/plesk-php83-fpm/error.log) shows these errors:

  [pool example.com] child 1111111 said into stderr: "NOTICE: PHP message: PHP Fatal error: Maximum execution time of 300 seconds exceeded in /var/www/vhosts/example.com/httpdocs/wp-content/plugins/plugin-name/includes/widgets/plugin-script.php on line 111"

• Manually terminating the PHP-FPM processes temporarily resolves the issue

Cause

The script keeps running and doesn't end, causing new processes to accumulate and hog CPU time.

Resolution

To permanently resolve the issue, contact the plugin support. To work around the issue:

• Increase the max_execution_time to allow the script to end
• Limit pm.max_requests to prevent new processes from being created
• Disable the plugin from WP Toolkit > example.com > Plugins tab