Knowledge Base

How to enable caching on Turbo Web Hosting

This article describes how to enable caching on a Turbo Web Hosting account.

Enabling caching

By default, caching is disabled on Turbo Web Hosting accounts. To enable caching for your account, you use directives in an .htaccess file. These directives enable you to control precisely which types of content the Turbo Web Hosting server caches, and for how long. You should create the .htaccess file in the base folder for the application that you want to cache.

You can use multiple .htaccess files in different directories to specify different cache control settings for each application.

The following sample configuration demonstrates how to enable caching on a Turbo Web Hosting account:

<IfModule LiteSpeed>
    CacheEnable public
    RewriteEngine On
    RewriteCond %{REQUEST_METHOD} ^GET|HEAD$
    RewriteCond %{HTTP_HOST} ^example.com [NC]
    RewriteCond %{REQUEST_URI} !login|admin|register|post|cron
    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.
  • If you want to enable caching for multiple domains, separate them with the pipe ('|') symbol. For example:
    RewriteCond %{HTTP_HOST} ^example.com|example.net|example.org [NC]
    

Let's go through this example configuration line by line:

  • The first line checks to make sure the Turbo Web Hosting server is running LiteSpeed.
    Strictly speaking, you do not have to use this line (and its corresponding line at the end of the file), but it is good practice to do so, particularly if you use the .htaccess file on a different server in the future.
  • The second line enables the public cache. Turbo Web Hosting servers have a public and private cache. Usually, you want to use the public cache, which caches content for multiple clients. The private cache is used to cache content for a single client (for example, personal information for an authorized user).
  • The third line turns on URL rewrite functionality. Turbo Web Hosting servers use rewrite conditions and rules to control caching behavior.
  • The fourth, fifth, and sixth lines use RewriteCond directives to specify what should and should not be cached. The REQUEST_METHOD condition instructs the server to cache GET and HEAD requests, but not POST requests. The REQUEST_URI condition, because it begins with an exclamation mark (!), instructs the server to not cache any page whose URL contains login, admin, register, post, or cron.
    To add additional strings to the REQUEST_METHOD or REQUEST_URI conditions, use the pipe symbol (|) to separate them.
  • 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.
  • The RewriteRule directive actually sets the cache duration. In this example, pages are cached for five minutes (300 seconds).

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.

More Information

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