High Performance WordPress

Slide 1: High Performance WordPress Barry Abrahamson Matt Mullenweg July 22, 2007 WordCamp 2007 – San Francisco, CA

Slide 2: The Problem • Serve as many users as possible with a reasonable amount of resources

Slide 3: Un-tuned LAMP Stack • Linux, Apache 2, PHP 4 or 5, MySQL 4.1 or 5.0 • 8 requests/sec • 691,200 pageviews/day • Enough for > 99% WP installations

Slide 4: Alternative PHP Cache (APC) • http://pecl.php.net/package/APC • 12 requests/second • 1,036,800 pageviews/day • 50% performance increase

Slide 5: WP-Cache • http://mnm.uib.es/gallir/wp-cache-2/ • 300 requests/sec • 25,920,000 pageviews/day • 25x increase!!!!! • Possible gotcha – http://markjaquith.wordpress.com/2006/02/13/adventures-with-wp-cac

Slide 6: Apache Alternatives • High concurrency • Majority (90%) of requests on a page are static • Litespeed, lighttpd, apache + fcgi, proxy

Slide 7: PHP 5 – Just for fun • Same as PHP 4 without APC • Same as PHP 4 with APC 3.0.14 • Using APC from CVS, PHP5 is 15% faster than PHP4

Slide 8: When one isn’t enough • Move the database to a second server (or 50) • HyperDB • Load balancing

Slide 9: HyperDB

Slide 10: Load Balancing • Hardware or software? • Pound – http://www.apsis.ch/pound/ • Thousands of requests/sec • Layer 7

Slide 11: Caching • Memcache – http://www.danga.com/memcached/ • Varnish – http://varnish.linpro.no • WP-Cache alternatives

Slide 12: WordPress.com • Over 1.2 million blogs • 10+ million pageviews/day (dynamic) • 40+ million hits/day (static + dynamic) • 7,000+ database queries/second • 80,000+ memcache calls/second • http://wordpress.com/stats/

Slide 13: Questions