Let’s do a simple experiment together. Go to your Joomla website, type in something like: http://www.[yourjoomlawebsite].com/test.jpg (assuming you do not have a test.jpg file in the root directory of your Joomla website).
You will notice that Joomla displays a 404 error. What’s wrong with that, you may be wondering? Well, what is wrong is that the whole Joomla environment is being loaded when a simple “404 – Not Found” error would have been sufficient. Of course, on small websites, this is hardly an issue, but, on large websites with high traffic, it is.
Now the question is, why is Joomla handling all the 404s, instead of just handling the 404s related to articles not found? Well, it is because of the following code in the default Joomla .htaccess file:
# If the requested path and file is not /index.php and the request
# has not already been internally rewritten to the index.php script
RewriteCond %{REQUEST_URI} !^/index\.php
# and the requested path and file doesn't directly match a physical file
RewriteCond %{REQUEST_FILENAME} !-f
# and the requested path and file doesn't directly match a physical folder
RewriteCond %{REQUEST_FILENAME} !-d
# internally rewrite the request to the index.php script
RewriteRule .* index.php [L]
If you have some experience reading and understanding .htaccess files, you will know that the above tells Joomla to process requests to non-existing files and directories, which means that any hit on the domain with a file or a folder that doesn’t exist will eventually reach the index.php file, and ultimately load the Joomla environment. As mentioned in the article we linked to above, this can cause performance and stability issues on the server, especially on sites with lots of content and very high traffic.
So, how can one solve this problem?
Obviously the solution to this problem is to tell the Joomla environment to only execute non-file requests (we cannot block it from executing directories, because a non-existing directory can be a valid Joomla link). This can be done in the .htaccess file, by adding the following code just after the RewriteEngine On line:
# if the file doesn't exist
RewriteCond %{REQUEST_FILENAME} !-f
# and the file extension is one of the below
RewriteRule ^(.+\.(?:css|gif|jpe?g|js|pdf|php|png|xml))$ 404.php [L,NC]
Before adding the above code to your .htaccess, you will need to create the file 404.php in the root directory of your Joomla website. This file should only contain the following couple of lines (a mini-sized file ensures that the server performs minimal work and that traffic spent on non existing files is minimal):
<?php header("HTTP/1.0 404 Not Found");
die('404 - not found');?>
Once you do the above, you will notice that non-existing files will no longer be processed by the Joomla engine – which is a good thing – as this will lower the server load. If you have a large website, then the performance gain by adding the few lines of code above will be noticeable.
We hope that you found this post useful. If you need help with the implementation, then please contact us. We are always there for you, our fees are super affordable, and our work is super clean!