How to prevent your wordpress installation from overloading your shared server (or how to survive the digg effect on your wordpress blog):
WordPress blogs can be extremely resource intensive if you happen to experience a surge in traffic. Poorly implemented wordpress setups can place a high load on webservers and lead to interruptions of service or account suspensions for using too many resources . Here are some tips that can help you make your wordpress install more stable
1. Use one of the following cache plugins :
a) WordPress super cache plugin ( http://wordpress.org/extend/plugins/wp-super-cache/ )– The number one thing you can do to improve wordpress performance is install a page cache. WordPress super cache plugin is an extensive modification of the WP-Cache plugin. The wordpress super cache plugin serializes your posts to a file on disk and later spits them back. It also knows how to update itself when comments are received, etc, so your site is always the most up to date. I can not recommend this plugin enough if you wish to have a stable and responsive wordpress install. Note: to use this plugin you must have Mod_Rewrite enabled. Add the following to your .htaccess file:
Options +FollowSymLinks
RewriteEngine On
Please see http://wordpress.org/extend/plugins/wp-super-cache/ for more information.
b) Quick Cache ( A WP Super Cache Alternative )
The Quick Cache plugin uses configuration options, that you select from the options panel. See: Config Options under Quick Cache. Once a file has been cached, Quick Cache uses advanced techniques that allow it to recognize when it should and should not serve a cached version of the file. The decision engine that drives these techniques is under your complete control through options on the back-end.
Please visit http://wordpress.org/extend/plugins/quick-cache/ to get more information about this plugin .
2. WP Built-in object cache – The default installation of wordpress can be used to cache database queries. Less database queries = less resources being used and that makes us all happy.
Just add the following line to your wp-config.php file:
// Enable the WordPress Object Cache: define(ENABLE_CACHE, true);
Review your plugins – You should go though the plugins you have installed and see if there is a way to make them faster. Any way in which you can make them stop creating database queries and use flat files, or even better, cache things will help out greatly. If you find that a particular plugin is slowing down your wordpress install you should uninstall the plugin and consult the author. Most plugin developers love to hear feedback and would greatly appreciate your help.
3. Use a plugin monitor to see which plugins are using your resources. You can download pluginhogdetector from http://money.bigbucksblogger.com/pluginhogdetector-plugin-helps-you-find-cpu-hogging-plugins/ just deactivate it when your not monitoring as it will use a lot of resources too.
4. If you are doing media-rich applications and serving large files you may want to consider hosting these files on a VPS or dedicated server.
5. Keep your wordpress install up to date.