1. A Crash Course in
Scaling WordPress

2. A Crash Course in
Scaling WordPress
or: let me at least
show you what is possible
(in 8 minutes)

3. A Crash Course in
Scaling WordPress
or: let me at least
show you what is possible
(in 8 minutes)

4. A Crash Course in
Scaling WordPress
or: let me at least
show you what is possible
(in 8 minutes)
[and then I'll take questions]

5. • Andrew Nacin
• Lead Developer for WordPress
• Washington, D.C.
• Work for WP founder Matt Mullenweg
(Don't work for Automattic or WP.com)
• Full time on WordPress (the project)
and WordPress.org (the site)

6. WordPress can scale
(no, really!)

7. WordPress can scale
(and it's easy!)

8. nginx

9. nginx

10. nginx

11. nginx

12. nginx

13. nginx
(with PHP-FPM)

14. • nginx is a web server (like Apache or IIS)
• nginx is better
• nginx is so much better it isn't even funny
• Well-tuned Apache can serve a few hundred
requests a second
• nginx can serve 10,000 requests/sec and up

15. nginx can be a…
• request router/load balancer (layer 7)
• load balancer(layer 4)
• front end proxy (often proxying to Apache)
• web server (using PHP-FPM)
• cache (fastcgi_cache and proxy_cache)

16. nginx can be a…
• request router/load balancer (layer 7)
• load balancer(layer 4)
• front end proxy (often proxying to Apache)
• web server (using PHP-FPM)
• cache (fastcgi_cache and proxy_cache)
and it is all of these things for WP.com and WP.org

17. If you can't switch out Apache
(because reasons)
Try to still still use nginx
as a front-end proxy
and caching layer

18. At the PHP level:
Use the latest version of PHP
for security and performance
Turn on PHP opcode cache,
also called a PHP accelerator
• APC (until PHP 5.5)
• Zend Optimizer+ (PHP 5.5 and up)

19. Inside WordPress (Objects)
Enable object caching in WordPress
• stores objects in a key-value store like
APC, Memcached, Redis, and WinCache
– APC for one server, Memcached for multiple
• avoids database queries
• improves speed and performance
• lowers memory consumption

20. Inside WordPress (DB)
Have multiple database servers?
Use HyperDB by Automattic.
• splitting reads/writes
• master/slave setups
• DB failover
• sharding
• multiple databases
• multiple datacenters (mind blown)

21. Inside WordPress (Debugging)
• Use the Debug Bar plugin
by the WordPress core team
• It's like Firebug or the Web Inspector,
but for WordPress
• Inspect queries, cache hits, performance
• Watch for errors and deprecated notices
• General debugging
• Look for issues with themes and plugins

22. Inside WordPress (Page Caching)
• Temporarily Caching entire pages and
serving those pages as fast as possible
– nginx can do most of this for you
• Batcache by Automattic
(You may have also heard of
W3 Total Cache & WP Super Cache)

23. At the hardware level:
(Solid-State Drives)
SSDs

24. one server, 10,000 requests/sec
864,000,000
requests a day

25. • nacin@wordpress.org
• Questions?