wordpress performance & scalability

WordPressPerformance & Scalability

Joseph Scotthttp://josephscott.org/

Find Me

• http://josephscott.org/

• [email protected]

• http://twitter.com/josephscott/

• #wordpress-dev

Backup First

Performance

Shelby Supercars Ultimate Aero Twin Turbo

Scalability

Web Apps Are LikeOgres Onions

Start At The BottomDeal with network problems / bottlenecks first

Be familiar with Operating System network optimizations

Web Server

Apache?

Web Server

nginxhttp://nginx.net/

lighttpdhttp://www.lighttpd.net/

LiteSpeedhttp://litespeedtech.com/

Zeushttp://www.zeus.com/

Apache• Can be a pig, remove any modules you aren’t

using

• Turn off host name lookups

• Turn on compression (mod_deflate)

• Turn off FollowSymLinks (and .htaccess if you can)

• Skip Apache all together, serve static content from another server

PHP

• Use an opcode cache (APC, lots of others)

• Don’t use on static files (unless you really, really need to)

• Consider output buffering

• Be careful with preg_* functions

MySQL - Table TypesMyISAM

• High performance reads or writes, not both

• Full text search

InnoDB

• Better for mixed reads/writes

• Transactions, Foreign Keys

MySQL• Double (and triple) check indexes

• Tune your configuration

• key_buffer_size, table_cache, sort_buffer_size, read_buffer_size

• Replication (more on that later)

• Interesting quirks, get familiar with them

Memcache

In memory object cache, learn it, use it, love it

With Caution

WordPress• MySQL tables default to using MyISAM,

consider using InnoDB instead

• Turn off unused plugins

• Check that themes and plugins aren’t abusing MySQL or PHP

• Server static content from another server (optimized for that task)

Construction

Start from the bottom andwork your way up

Test Setup

• Ubuntu 9.04 server edition

• Apache 2.2.11

• PHP 5.2.6

• MySQL 5.0.75

• WordPress -trunk

Test “Hardware”

Parallels 4.0

2.66 Xeon1 GB Ram

Abusing The Serversiege - http://www.joedog.org/index/siege-home

siege -d 1 -c 50 -r 10 http://192.168.1.100/

Below The Baseline

Zero Byte HTML - zero.html (80 r/s) ~0.01 s/r

Zero Byte PHP - zero.php (80 r/s) ~0.01 s/r

a phpinfo( )’s worth

static HTML - phpinfo.html100% (75 r/s) ~0.04 s/r

PHP - phpinfo.php92% (69 r/s) ~0.04 s/r

51,213 / 8,689 bytes

Hello World!

WordPress: /wp/?p=1

6,582 / 2,531 bytes

Hello World!

WordPress: /wp/?p=18% (6 r/s) ~7 s/r

6,582 / 2,531 bytes

Hello World!+ APC

WordPress: /wp/?p=129% (22 r/s) ~1.51 s/r

Use An Opcode Cache!%8 ~7 %29 ~1.51

WordPress + Memcache

• Ryan Boren

• Stores WordPress data in Memcache

• Reduces the number of database queries

• http://ryan.wordpress.com/2005/12/23/memcached-backend/

Hello World!+ APC + Memcache


Batcache!

WordPress + Batcache

• Andy Skelton

• Stores rendered HTML in Memcache

• http://wordpress.org/extend/plugins/batcache/

Hello World! + APC + Memcache + Batcache


WordPress+ WP Super Cache

• Donncha O Caoimh

• Stores rendered HTML on disk

• http://wordpress.org/extend/plugins/wp-super-cache/

Let me 'splain. ...No, there is too much. Let me sum up.

DescriptionRequests

per SecondSeconds per

request (mean)Potential

Zero Bytes 80 ~0.01 -Static phpinfo() 75 ~0.04 100%phpinfo() 69 ~0.04 92%OOB WP 6 ~7.00 8%WP & APC 22 ~1.51 29%WP & APC/Memcache

24 ~1.40 32%

WP & APC/Memcache/Batcache

60 ~0.04 80%

What Now?

All In One

Web / Database

Moving Out

Web Database

Paying In Cache

Web

DatabaseMemcache

But Wait, There’s More!

MySQL Replication

• Master / Slave - one way asynchronous

• Send writes to the master, reads to the slave(s)

• Replication works on both MyISAM and InnoDB tables

• Supports multiple slaves and replication chaining

Enter HyperDB

• Drop in replacement for the default WordPress database class

• Supports distributed reads/writes

• Partition data (helpful for large WPMU installs)

• Failover support when a database goes down

• http://codex.wordpress.org/HyperDB

Replicated Data

Web

DB Master

MemcacheDB Slave

A Balancing Act

Web 2

Load Balancer

Web 1 Web 3

Variations on a Theme

• Master / Relay / Slave

• Slave just for backups

• Multiple data centers

• Task specific web servers

When Everything Goes Wrong

Hire An Amazing SysAdmin

Thank You

Find Me

• http://josephscott.org/

• [email protected]

• http://twitter.com/josephscott/

• #wordpress-dev

wordpress performance & scalability

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