WordPress Optimization and Speed

I’ve been having problems with my sites for a while now on various different VPS web hosting servers. Essentially, I’m getting intermittent faults, the worst kind and hardest to diagnose nevermind fix! Basically all my sites can be running fine then for no reason and without me making any changes to any site, they become incredibly slow. The server and/or apache dies more often than I’d like it too aswell, requiring a manual server restart.

I decided to do a bit of proper research and fault finding this week and while I can’t say for sure everything is fixed now, as of this moment, everything seems fine. Here’s a few of the things I done to try optimize a couple of my biggest, most trafficked sites – both WordPress blogs.

Basic Optimization

• Update WordPress itself to the most recent version,
• Update all plugins,
• Remove plugins that you don’t really need or which you can easily replicate the functions of by hardcoding, ie – Facebook Like Buttons,
• Limit plugins that communicate with external sources, ie – Facebook boxes, Twitter feeds, etc..,
• Only use plugins included in the WordPress.org database,
• Only use plugins that are listed as 100% compatible with your WordPress version,
• Keep images small and image numbers low,
• Use HTTP Compression,
• Use a Caching plugin like W3 or WP Super Cache,

Advanced Optimization

• Database Queries tend to slow down a WordPress site so check your number by adding "<!-- <?php echo get_num_queries(); ?> queries. <?php timer_stop(1); ?> seconds. -->" to your code and checking the page source on load,
• Debug your Queries by adding the Debug Queries plugin to see what the actual queries are and how long each one takes,
• Optimize your WordPress tables via phpMyadmin if you have access to it. The WP DB Manager plugin does this too if not,
• Delete database tables that have been left over by deactivated or deleted plugins. Be careful here!
• Turn off post revisions by adding “define('WP_POST_REVISIONS', FALSE);" to your wp-config file,
• Delete all comments marked as spam via sql query – DELETE FROM  wp_comments WHERE  comment_approved = 'spam';,
• Clean orphaned or unused entries in the WP-options table using the Clean Options plugin. Be careful!
• Raise the default WordPress memory limit of 32MB by adding define('WP_MEMORY_LIMIT', '64M'); to the wp-config file,

Finally, you can create a basic error log for your WordPress site by adding the following lines to the wp-config file:

@ini_set('log_errors','On');
@ini_set('display_errors','Off');
@ini_set('error_log','/path/to/wordpress/blog/php_error.log');


Here’s a great article on WordPress Database Optimization.

Good Luck.

Leon.