We have talked before on when to clear your cache in Joomla, so probably you have read the article and thought that now is the best time to do it. So, you went ahead and disabled the cache, thinking that this will delete your cache. But your pages are still cached. Weird!
You double check if you did the right thing, so you repeat the process: You go to Site – Global Configuration, and then you click on System (in the secondary menu below), and then yo choose “No” next to Cache under Cache Settings. You click on Save on the top right and then you refresh the configuration page just to make sure that your settings were saved, and they were indeed saved. You go back to your website, and you check, and, to your horror, the cache is still there. What gives?
See, the problem is that by doing the process above, you didn’t delete the cache, you just partially disabled it. Now, in order to clear your cache in Joomla, you go to Tools – Clean Cache, and then you click on Site, and then you click on the checkbox next to the # sign (this checkbox should check all the checkboxes there), and then you click on Delete on the top right. You should also do the same for Administrator (next to Site).
Now what if the cache is still not clearing? According to our experience in Joomla, there are several reasons for this to happen:
- Modified Permissions on the cache directory: This means that Joomla is now unable to modify the cache directory (usually this results from a manual modification to that directory). This consequently means that not only you’re not able to delete the cache, but that Joomla is also unable to write to the cache directory (usually the error log located under the root of your website will contain information about this permission problem). So, in this case, when your cache expires, your website will perform as if caching was not enabled.
Your Joomla cache directory has too many cached pages: This generally happens in very large websites. We have seen Joomla websites with over 1,000,000 cached pages (yes, that’s 1 million pages). Deleting those cached pages may take a long time or may be interrupted by a PHP script timeout. But, sooner or later, the cache will be cleared (so you don’t have to worry).
There is a locked file in your cache directory: Sometimes, a file might be locked (as another process is attempting to read or write from it). While this is very rare, it did happen with one of our clients.
You are using a 3rd party extension for caching: There are many non-native extensions that do the caching. Cache generated when these caching extensions are activated is not cleared using the normal way. So, you must read the documentation for your caching extension to see how to clear your cache.
A few things we would like to mention:
- You can see from the above that we said that setting the Cache to “No” under configuration will only partially disable the cache, meaning that there will still be caching (there are several levels of caching in Joomla). Now in order to disable the cache completely in a default installation of Joomla, you will need to go Extensions – Plugin Manager, and search for the “System – Cache” plugin, and disable it. By doing so (and setting the Cache to “No” in the configuration) there will be no more caching done on your Joomla website.
You don’t have to disable the cache in order to delete it.
It might be that your cache is deleted but it’s being re-generated the second you delete it (this happens when your website receives many visitors)