Performance increase for sites with large user counts (now also available on single site)

In WordPress 6.0, websites with more than 10,000 users will see improvements in handling users. Prior to changes in #38741, sites with more than 10,000 users would suffer from slow page loading time in the user and post list screens. 

The user screen was slow because a complex SQL query was run to get the number of users for each role. This sometimes resulted in page timeout or failures to load. On the post edit screen, a dropdown of authors in the quick edit option used to change the post’s author. On large sites, this results in thousands of options rendered on the page, which creates a large amount of markup and causes timeouts and slowdowns. 

Introducing large sites

The idea of a large networknetwork (versus site, blog) in multisitemultisite Used to describe a WordPress installation with a network of multiple blogs, grouped by sites. This installation type has shared users tables, and creates separate database tables for each blog (wp_posts becomes wp_0_posts). See also network, blog, site configurations of WordPress has existed since WordPress 3.0. A network is considered large when it has over 10,000 users. When marked as such, any real time calculation of the number of users is skipped and all counts of users are deferred to scheduled (cron) events. 

This idea of a large network has now been ported to single site installs of WordPress. Any site with more than 10,000 users is marked as large. Once this threshold is met, real time counts, such as ones noted above, no longer occur on every page load. This means that when viewing user lists, the count next to each user role will be missing. This massively improves the performance of the page page load and prevents slow database queries causing PHPPHP The web scripting language in which WordPress is primarily architected. WordPress requires PHP 5.6.20 or higher timeout errors, which in turn helps ensure the user list renders every time on large sites. 

This change includes some new functions:

  • get_user_count
    Now available for both single- and multi-site installations. For sites with over 10,000 users recounting is performed twice a day by a scheduled event. 
  • wp_update_user_counts
    Perform a user count and cache the result in the user_count site option. 
  • wp_is_large_user_count
    Determines whether the site has a large number of users. The default threshold of 10,000 users can be modified using a filterFilter Filters are one of the two types of Hooks They provide a way for functions to modify data of other functions. They are the counterpart to Actions. Unlike Actions, filters are meant to work in an isolated manner, and should never have side effects such as affecting global variables and output. of the same name.

Now that the get_user_count is available for both single and multisite, it is strongly recommended not to use the count_users function in your code. This function is not performant and is the root cause of issues noted above. Wherever possible, every instance of count_users in coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. has been converted to use get_user_count, which is also recommended action for pluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the Plugin Directory or can be cost-based plugin from a third-party authors. 

Props to @kkautzman, @milana_cap, and @bph for review and proofreading.

#6-0, #dev-notes, #dev-notes-6-0, #performance