WP Super Cache is one of most popular plugins for caching in WordPress. It has static page caching, database cache, browser cache, gzip, etc. - almost everything you need to make your website faster. It's just a problem I met when using it in my MultiSite install and I'd love if it can be improved. It's not a kind of bug, only a bad behavior, I think.
I installed WP Super Cache the plugin for MultiSite and network activated it. The problem appears when I deactivated it for testing: it didn't remove its files in
wp-content folder and some rules in
.htaccess. That made the pages still cached and I couldn't test my websites.
The files in
wp-content are Dropin plugins. There's not much documentation for this kind of plugin. Briefly, they're used to replace some default functionality of WordPress. Frank has written a good post about that and listed some popular files. WP Super Cache uses those files to enhance the cache functionality in WordPress. When the files are still there - those functions still in action, meaning you still have page cached somehow. That's unexpected when you deactivated the plugin!
The rules in
.htaccess are used for browser caching and redirect requests to static page cache. WP Super Cache defines the expire time of resources in website like javacscript, css, images files. It also redirects requests to static HTML version of the pages (non-gzip or gzip based on the request). So when these rules are still there, those things are still cached and I couldn't see the changes I made. Even when I clear browser cache, it still displayed the static cached pages.
But everything is fine if I deleted (uninstalled) the plugin. Those things are removed totally. So uninstalling is a good practice.
All I want to be included in the plugin is that it removes files in
wp-content and rules in
.htaccess. It can still keep its option in the database when deactivating and remove the option only when uninstall (delete) - it's a good practice in WordPress and is recommended by many developers.
Right now, I'm using the HyperCache plugin at Deluxe Blog Tips. It's a good plugin at start, I'll write more about it in another post.