Comments in 4.6 can now be cached by a persistent object cache

The ‘comment’ cache group was made non-persistent in [7986], to address the difficulty of reliable cache invalidation. This meant the comment cache values were only held for the current page load, and lost on reload or navigation. The comment APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways. has improved since WordPress 2.6, and cache is king.

In WordPress 4.6 the ‘comment’ cache group has been removed from the list of non-persistent cache groups, see [37613]. When comments are added, modified, or deleted we properly invalidate out of date cache values. You can now cache with confidence.

If you have a 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 which modifies comment data directly please change them to makemake A collection of P2 blogs at, which are the home to a number of contributor groups, including core development (make/core, formerly "wpdevel"), the UI working group (make/ui), translators (make/polyglots), the theme reviewers (make/themes), resources for plugin authors (make/plugins), and the accessibility working group (make/accessibility). use of the various comment API functions or use clean_comment_cache().

Don’t miss out on this change. For more background on the change, see #36906.

#4-6, #comments, #dev-notes