Cron Improvements with PHP-FPM in WordPress 5.1

A new change in 5.1 Beta 1 introduces a change in behaviour for cron spawning on servers running fastcgi and PHPPHP The web scripting language in which WordPress is primarily architected. WordPress requires PHP 5.6.20 or higher 7.0.16+.

When available, requests to wp-cron.php will now return a repsonse immediately, before processing lengthy cron jobs, allowing the request that spawned the cron process to end without blocking regardless of the transport method used to trigger it. See #18738 for discussion and research.

This should work well on PHP-FPM installs and cause no issues on other servers. We could use some testing and reports to confirm this, since a similar method could be used in other contexts such as shutdown hooksHooks In WordPress theme and development, hooks are functions that can be applied to an action or a Filter in WordPress. Actions are functions performed when a certain event occurs in WordPress. Filters allow you to modify certain functions. Arguments used to hook both filters and actions look the same. if it proves to be safe and reliable (see #41358, #27669, #27122).

#5.1 #dev-notes