markkelnar | WP Engine
@renderandserve | howdy
WordCamp Atlanta 2012
Who is this guy?
Head of Technology, System Administration, database,
product development at WP Engine
I'm not a power-point guy, please excuse my mistakes. If I had my way, this presentation would
look like this
class WCATL extends presentation
$this>name = 'Word Camp Atlanta';
$this>bg_color = '#808080';
$p = new WCATL();
Why are you here?
You want your site fast
Keep readers/customers on your site
Survive heavy visitor load
Scale – When you're on techcrunch, mashable or
daringfireball, you want to survive
You are doing it wrong!
But you don't know it.
Who are you?
Site admin, content contributor
Designer, theme developer
Backend developer, admin, dba, etc.
What can I optimize?
Hosting is about layers, but which one?
Layman's term, not that techno-jargon ...
HTML, CSS, JS, images, web server, database, WordPress,
theme, plugin, cache, minify
LAMP, TTL, CDN, cache, Apache, PHP, static content,
Where do I start?
Use profiling tools to find your bottleneck
yougetsignal.com (reverse IP address)
Command line fun:
`ab -n 100 http://wpengine.com` (Apache Benchmark)
`curl -I wpengine.com` (that's a dash-eye)
Content Delivery Network
Have another service serve your static files (jpg, js, css) from their domain
Say that again? Off-load statics (jpg, png, css, js) so it doesn't load from your
Store static files closer to end user – global proximity
Paths in your HTML point the browser to the CDN service:
Cloud cache service (CloudFlare), Amazon S3, etc
Paths – It's all in what your HTML tells the browser
content/uploads/family.jpg" alt="shredder" />
When the service mark.some-cdn-service.com needs the image, after TTL has
expired, the cdn service loads (pulls) a fresh copy from markkelnar.com
Poor-man's CDN, serve images from Flickr
Amazon S3 – host entire site there, or even just statics
Use external source for comments, like disqus-comment-
Popular posts / related content metrics – outbrain, nrelate
WPSmush it plugin
Everytime you add an image, it does it for you. Yahoo! Smush all your existing
Do the other fun front end developer
Minimize HTTP requests – CSS sprites
CSS at the top of the page, JS at the bottom
Search for “Yahoo performance rules”
Ads on your page
Load them asynchronously or maybe iframe.
Are your ads cache busting? Do they have to?
Load from multiple
Difficult to do. More overhead to configure and support.
That's front end tweaks
What good is a fast front end with a slow back end?
What if the back end can't handle what still comes through?
Review your theme
know your theme. Did you buy it? Codex? Off the street?
- does it validate?
CSS at the top, JS at the bottom (not inline)
- Any weird code (if it looks bad, it probably is)
- weary of file_get_contents() / fgets()
- base64_decode() (injected malware or unnecessarily compressed code)
Pull your data wisely
What could possibly go bad here?
Keep WP up to date
Why wouldn’t you?
Code optimizations, core changes,
- deactivate plugins you don’t use at all
- delete plugins you don’t use at all
Bad PHP code
Poor use of DB calls, update/insert to DB on every page load
Don't scale under load, cripple the back end
Put stuff on wp-cron scheduler that pops too often.
Ex: (but not limited to)
- backupwordpress backwpup
- LinkMan (MyReviewPlugin Link
- MyRP (MyReviewPlugin)
Beware of poor
How many requests to your blog are /feed?
Are you using a service like feedburner?
Show me the cache!
Let's start with plugins
Has features to do CDN path rewrites, page and object and db caching,
minification, cache purging/clearing
JS, CSS – remove white space, comments sent to end user (browser)
What is it?
HTTP Cache-Control, Expires headers,
Entity Tags (ETags)
Already done for me?
on server and uncompressed in
Server side caching
What is it?
saves bandwidth and improves performance
HTTP Accelerator server–
reverse proxy caching behind nginx
Memcached server –
object caching, persistent vs transients
caching compiled PHP code bytecode
in memory key-value storage for data, transients
full caching of HTML page
Tools for the job:
APC, Eaccerator, Xcache, Zend Optimizer, ionCube
- Move as much as possible out of Apache
- Stand up Nginx in front of Apache (reverse proxy)
- Don't run your PHP in Apache at all, use PHP Fast CGI,
- Server static files from disk in Nginx
- Put known redirects (301/302 in Nginx config)
- Move .htaccess rules to Apache httpd.conf or better yet
- Google Page Speed Apache module
- Optimize tables, clean house
- PHPMyAdmin, OptimizeDB, manually
- Tables, Innodb (transactional, faster for writes) vs
MyISAM (can be less memory)
- Master/Slave replication + HyperDB
- dedicated server(s)
- turn on log and investigate mysql-slow.log
- database caching
If you're reading this, you're too
metal server vs virtual or cloud instance
*nix, sun, MS
compiled, package installed
CPU + cores, memory, SSD disk drives
: MySQL, Percona,
- Don't edit WP-core files (wp-includes, wp-admin)
- Amazon EC2 not silver bullet
- Beware of plugins that update database tables on every
page load. Use external resources.