High Performance WordPress Barry Abrahamson
Matt Mullenweg July 22, 2007 WordCamp 2007 – San Francisco, CA

The Problem <ul><li>Serve as many
users as possible with a reasonable amount of resources </li></ul>

Un-tuned LAMP Stack <ul><li>Linux, Apache
2, PHP 4 or 5, MySQL 4.1 or 5.0 </li></ul><ul><li>8 requests/sec </li></ul><ul><li>691,200 pageviews/day </li></ul><ul><li>Enough for > 99% WP installations </li></ul>

Alternative PHP Cache (APC) <ul><li>http://pecl.php.net/package/APC
</li></ul><ul><li>12 requests/second </li></ul><ul><li>1,036,800 pageviews/day </li></ul><ul><li>50% performance increase </li></ul>

WP-Cache <ul><li>http://mnm.uib.es/gallir/wp-cache-2/ </li></ul><ul><li>300 requests/sec </li></ul><ul><li>25,920,000
pageviews/day </li></ul><ul><li>25x increase!!!!! </li></ul><ul><li>Possible gotcha </li></ul><ul><ul><li>http://markjaquith.wordpress.com/2006/02/13/adventures-with-wp-cache2-apc/ </li></ul></ul>

Apache Alternatives <ul><li>High concurrency </li></ul><ul><li>Majority
(90%) of requests on a page are static </li></ul><ul><li>Litespeed, lighttpd, apache + fcgi, proxy </li></ul>

PHP 5 – Just for
fun <ul><li>Same as PHP 4 without APC </li></ul><ul><li>Same as PHP 4 with APC 3.0.14 </li></ul><ul><li>Using APC from CVS, PHP5 is 15% faster than PHP4 </li></ul>

When one isn’t enough <ul><li>Move
the database to a second server (or 50) </li></ul><ul><li>HyperDB </li></ul><ul><li>Load balancing </li></ul>

HyperDB

Load Balancing <ul><li>Hardware or software?
</li></ul><ul><li>Pound </li></ul><ul><ul><li>http://www.apsis.ch/pound/ </li></ul></ul><ul><li>Thousands of requests/sec </li></ul><ul><li>Layer 7 </li></ul>

Caching <ul><li>Memcache </li></ul><ul><ul><li>http:// www.danga.com/memcached /
</li></ul></ul><ul><li>Varnish </li></ul><ul><ul><li>http:// varnish.linpro.no </li></ul></ul><ul><li>WP-Cache alternatives </li></ul>

WordPress.com <ul><li>Over 1.2 million blogs
</li></ul><ul><li>10+ million pageviews/day (dynamic) </li></ul><ul><li>40+ million hits/day (static + dynamic) </li></ul><ul><li>7,000+ database queries/second </li></ul><ul><li>80,000+ memcache calls/second </li></ul><ul><li>http://wordpress.com/stats/ </li></ul>

Questions