The highly rated and recommended WordPress caching plugin, WP Super Cache has problems. At least the current version has un-resolved bugs.
The main problem lies with the preload function. Cache Preload is supposed to create a cached (static) version of every page/post on the site using WP Super Cache, however in a number of instances the plugin fails to generate all (if any) cached files, and the common answer from support is “It shoudn’t do that”
3 Sites with WP Super Cache:
First: One of my client websites: This realtors website, hosted on GoDaddy Hosting in USA is using WP Super Cache at the moment. This caching plugin was only installed on the site because it is the one recommended by the hosting service, so should be totally compatible with their set-up. This hosting service is frankly terrible; it regularly takes over 15 seconds to read the database before it starts serving the request, so a good caching system is critical.
Second: Installed on a testing website hosted on Apache server. In this case the plugin works… but let’s have a look at the site configuration. This site is a basic installation of WordPress and serves no other purpose but to test plugins or themes, and has only some sample content…
Third: A live site hosted on the SAME server, with several other plugins, and around 80 pages of content. Nearly everything is identical to Site 2… except it is a working website, not a basic testing set-up. The preload caches 2 pages, occasionally 3 or 4. It doesn’t even generate a reason why the other pages are not cached in the debugging report. Nor can the expiry time be changed – it stays at 60 minutes no matter what settings are entered, so it’s either 60 minutes or “off”
Other WP Super Cache Bugs
wp supercache plugin broken imageThe plugin creates a cached page then deletes it shortly afterwards… First noticed on Site 1: The plugin is supposed to cache a page (in normal mode, not preload) when a visitors clicks on the page. It does, but deletes it even when all options to refresh the page or clear old cached files have been disabled…
After a day with several hundred page views for a number of pages, after a short time there is only one or two cached pages left tin the cache…no doubt having been visited within the time the plugin automatically deletes all cached pages regardless of settings.
Poor Support for WP Super Cache
For Site 1, the Super Cache Preload function for this site, only taxonomy pages (Tags and Categories) are cached by Preload, Normal webpages and blog posts are not. Debugging mode provides an indication of the reason, however the plugin support provides no useful answer to this particular bug report. The only answers seem to accuse the user who posted the report of not doing something correctly.
What tech support imageNumerous other user questions have been posted on the WordPress plugin support forum, the plugin developer website, and on tech forums elsewhere. The most common reply to Preload problem reports on WordPress.org is “It shouldn’t do that” – clearly the member responding to the question has no idea what is wrong with the plugin… Of course it ‘shouldn’t do that’. It should do what it’s advertised to do, preload every file on the site into cache.
One of the suggestions made is to use an earlier version of WP Super Cache. Why release a plugin claimed to be in stable WORKING format when it has so many problems that can only be solved by using an older version instead?