Screaming Fast Wpmu
- 1. Screaming Fast Wordpress Dan Collis-Puro Berkman Center for Internet & Society http://blogs.law.harvard.edu/djcp djcp@cyber.law.harvard.edu
- 2. Me ●Dev/sysadmin for 12 years ●Pro linux admin 9 years ●Perl / mod_perl / postgres / mysql / ruby / rails / php ●Mostly scrappy non-profits ●Geek-of-all-trades at Berkman ( http://cyber.law.harvard.edu) ●http://blogs.law.harvard.edu/ ●Help manage many servers and apps
- 3. Goals ●Use minimum resources to fulfill requests ●Survive the slashdot/digg effect ●Unobtrusive ●Easy to tune ●Optimize for different platforms / audiences ●If you hit the app server, you've failed ●If you MUST hit the app server, do what's reasonable to minimize resources
- 5. MySQL ●Optimize tables (with mysqlcheck and a cron job) ●Bump up query cache ●Tune key buffers ●mysqltuner.pl / tuning-primer.sh ●Might want more indexes, depending ●mytop ●Slow query log ●(meh) Clean out options table ●(meh) Clean out revisions / old spam ●(plugin) debug-queries
- 6. Linux ●RAM ●Never use swap ●Fast disk, database on its own spindles ●Fast network ●stat() kills you on network filesystems
- 7. Apache ●Use a reverse proxy ●Keepalive on frontend, no keepalive on backend ●Enable mod_deflate ●Set a sane MaxClients setting ●Use a lighter-weight frontend server – nginx! ●Use frontend proxy caching ●apachetop
- 8. PHP ●Enable opcode cache ●Make sure you allocate enough shared RAM ●Consider not allowing stat()s
- 9. Good / bad apc Good Bad
- 10. Wordpress ●Two major audiences: logged in and not. ●WP-SuperCache, W3 Total Cache ●Memcached is not a panacea. ●Nor is the WP object cache. ●Disable unused plugins ●CDN for media delivery
- 11. Our Problem ●750+ live blogs, some heavily trafficked and quite large ●Not too many simulateously auth'd users ●MANY spiders. Freakin' spiders! ●Mini-DDOSs each week ●ENORMOUS corpus of URLs to cache ●RSS feeds don't use feedburner
- 12. Our Solution ●nginx as a caching front-end proxy ●No plugins ●4 lines of code to the wordpress core ●Very flexible caching rules ●Able to cache for both audiences (sorta) ●Able to cache EVERYTHING. Period. ●Handles gzipping and logging ●Able to kill bad 'bots
- 13. Results ●Almost NO problems since implementation ●Atom feed from 6/sec to 2500/sec (network test) ●Atom feed from 3.95/sec to ~7000/sec (local test) (apache 3500 / sec) ●DOUBLED network throughput (?) ●Halved memory requirements ●Able to rip out all wordpress-level customizations and plugins. Except one.
- 15. Random Tools ●ab + bash ●firebug ●yslow ●Siege ●htop ●apachetop ●mysqltop ●EXPLAIN select
- 16. Photo credits: Characters: http://www.flickr.com/photos/goopymart Background: http://www.flickr.com/photos/roll_initiative I ♣ you! Get in touch: http://blogs.law.harvard.edu/djcp djcp on the twitterz djcp@cyber.law.harvard.edu dan@collispuro.com http://delicious.com/djcp - more specifically: http://delicious.com/djcp/screamingfastwp