Given at WordCamp Hamilton 2015, speeding up your WordPress site has great benefits - user satisfaction, SEO boost, better conversion, and saving money. Through internal tune-up and external optimization, you too can make your site faster.

1. Speed up your WordPress site
Alan Lok - WirelessLinx Inc.

2. Motivations
User experience1
Search engine optimization2
Your wallet
Less on-call issues!
1: http://www.webperformancetoday.com/2012/02/28/4-awesome-slides-showing-how-page-speed-correlates-to-business-metrics-at-walmart-com/
2: http://googlewebmastercentral.blogspot.ca/2010/04/using-site-speed-in-web-search-ranking.html

3. What is a LAMP stack
Database PHP Engine
Your app
Operating System
Web Server
Performance gains can be found in each layer
Reverse Proxy
Cache

4. Internal Tune-ups
Digging into your WordPress site to make it better

5. The simple stuff
Update your plugins
Remove unused themes and plugins
404 errors

6. WordPress plugins to speed things up
W3 Total Cache
Super Cache
Zen Cache

7. Different caches in WordPress core
Object Cache
wp_cache_get/wp_cache_set/wp_cache_delete
Backing onto a object cache library (memcached, Redis, APCu…)
Transcient Data
set_transient/get_transient/delete_transient
Saving data into database that is available to all instances
Both stores have a concept of timeout and developer-managed hit/miss management

8. Object Cache - Efficiency vs
Coherency
Efficiency:
reduce number of calls to your cache (or do a multi-get/set)
avoid remote cache if possible
Coherency
clustered cache allows for easier cache invalidation
Understand how cache works - cache makes debugging harder

9. Reduce and increase reuse
Lower number of HTTP requests
Combine CSS/JS files or inline them
Data URI
CSS sprites
Lower size of response
HTML/JS/CSS minification
Image optimization (eg. ImageOptim)
Reuse JS and CSS file for whole
site where possible
Personalization with AJAX

10. Profile your application
Analyze your application with a PHP profiler such as BlackFire or xdebug/
cachegrind
Look for high number of apply_filters, mysql calls, and wp_cache_get

11. Profile your DOM
Make your page render faster too

12. Database
Check your slow query log
Modify my.cnf to add general-log
and start seeing all database
queries per page
Reduce plugins or modify code if
possible to reduce queries
Try to “explain” your query

13. PSA: Signs of hacking
Check integrity of site and your VPS with tools such as wp-cli, or findbot.pl
Profiler showing high number of file operations
Seeing pharma or other links injected in header/footer

14. Operational Improvements
Improvements you can make outside WordPress

15. Make it faster by paying more money!
There is no such thing as
“unlimited” hosting or space
Ensure you are paying for the
level of performance you expect
given the traffic estimates
Diminishing returns on
performance when buying more
resources

16. Database
MySQL versions and variations
(MariaDB, Percona, Community)
DB Engine: Convert tables from
MyISAM to InnoDB
Some* my.cnf tuning
InnoDB buffer size, Query Caching
HyperDB for database splitting*
Some performance references:
http://www.liquidweb.com/kb/mysql-5-1-vs-5-5-vs-5-6-performance-comparison/
https://www.percona.com/blog/2011/10/10/mysql-versions-shootout/
http://vbtechsupport.com/657/

17. Web Server Technology
Web server technologies:
nginx vs Apache
PHP process management in Apache
php-fpm vs mod_php
prefork, vs worker/event
mod_pagespeed, php-opcache
When does it matter?
More food for thought:
http://blog.bitnami.com/2014/06/performance-enhacements-for-apache-and.html
https://www.digitalocean.com/community/tutorials/apache-vs-nginx-practical-considerations
Credit: Digital Ocean

18. HTTP changes
Content compression
Expiry headers for content type
Cache directive

19. Content Delivery
Reducing number of access to
your web server will reduce your
costs (bandwidth and CPU needs)
Consider using public CDN for
shared JS/CSS
Pay for a cheap CDN and use a
plugin to rewrite your assets to
the CDN

20. Web Application Protection*
SaaS: Sucuri / CloudFlare
Plugins: WordFence / Better WP
Security
Spam Protection: Akismet
PHP: suhosin
Server: mod_security
*not an exhaustive list or endorsement

21. Push vs Pull CDN
Push
CDN
Pull
CDN
CDN Data Store CDN Cache
Your Webserver
(origin)
cache miss
content push

22. Monitor your site
Application Performance
Monitor (eg. New Relic)
Server Monitoring (eg.
LongView, CloudWatch)
Last mile / Page Health
(eg. Kingdom)

23. Site Audits
Let’s look at a few sites together

24. Thanks!
Twitter: @alan_lok
Web: http://wlx.ca