How to enable caching for Drupal on Turbo servers

This article describes how to enable caching for Drupal on a Turbo server.

Enabling caching for Drupal

To enable caching for Drupal on a Turbo server, follow these steps:

1. In the directory where you installed Drupal, open the .htaccess file in a text editor. You can use one of the text editors in cPanel, or you can log in to your account using SSH and use a command-line editor.
   If the .htaccess file does not exist, create it.
2. Copy the following text and paste it at the top of the .htaccess file:

   <IfModule LiteSpeed>
       RewriteEngine On  
       RewriteCond %{REQUEST_METHOD} ^GET|HEAD|PURGE$
       RewriteCond %{HTTP_HOST} ^example.com [NC]
       RewriteCond %{REQUEST_URI} !admin|register|login [NC]
       RewriteCond %{HTTP_COOKIE} !SESS [NC]
       RewriteCond %{QUERY_STRING} !nocache
       RewriteRule .* - [E=Cache-Control:max-age=300]
   </IfModule>
   

   • These caching configuration directives must be at the top of the .htaccess file.
   • You only need to include the HTTP_HOST configuration line if you host more than one domain in the public_html directory (such as your primary domain and a subdomain). Replace example.com with the domain name for which you want to enable caching.
   • The QUERY_STRING configuration line enables you to see the non-cached version of any page by adding nocache to a query string in the URL. For example, to view the non-cached version of http://example.com/mypage, you could add ?any_field=any_value&nocache to the end of the URL.

3. Save your changes to the .htaccess file. Caching is now enabled.
   

   To verify that caching is working correctly on your account, you can examine the raw HTTP headers sent between the browser and web server. (To do this, use a browser plugin that displays the raw headers such as Live HTTP headers for Mozilla Firefox, or the Developer Tools feature in Google Chrome.) When content is served from the cache, the server adds the following line to the HTTP response header:
   

   X-LiteSpeed-Cache: hit

   If you do not see this line in the HTTP response header from the server, then the content was not served from the cache.

Caching and static content

Turbo accounts do not cache static content, such as audio and image files, on the web server. This type of content is cached by client web browsers instead. However, you can specify how long web browsers should cache your static content by using the ExpiresByType directive in the .htaccess file. For example, the following lines instruct web browsers to cache MP3 files for one year (31557600 seconds) and GIF files for 30 days (2592000 seconds):

ExpiresByType audio/mp3 A31557600
ExpiresByType image/gif A2592000

For more information about the ExpiresByType directive, please visit https://httpd.apache.org/docs/2.4/mod/mod_expires.html#ExpiresByType.

More Information

For detailed information about LiteSpeed caching, please visit http://www.litespeedtech.com/support/wiki/doku.php?id=litespeed_wiki:litespeed:cache.