managing multisite: lessons from a large network

Managing MultisiteLessons from a Large Network

William Earnhardt - @earnjam

WordCamp RaleighNovember 9, 2014

Single Site vs MultisiteSingle Site Multisite

One WordPress Install ✓ ✓

One Database ✓ ✓

Supports Themes ✓ ✓

Supports Plugins ✓ ✓

Number of Websites 1 Unlimited*

*Only limited by system resources

The 7 Minute Install

Step 1: Do the famous “5 Minute Install”

Step 2: Add this to wp-config.php

Step 3: Go to Tools > Network Setup

and follow instructions.

Pros & Cons of MultisitePros:• Updates

• Reusability of code

• Shared Database

• Security

• Messaging

• Single Sign-On

Cons:• Updates

• Reusability of code

• Shared Database

• Security

• Single Point of Failure

Should You Use Multisite?

Absolutely• A group of related sites

• Need to allow users to create new sites

Probably Not• Unrelated client sites

WordPress at Carolina

Web.unc.eduSelf service web publishing for

Carolina faculty, staff, and

students.

Sites.unc.eduEnterprise web platform for

divisions, departments, schools,

and more.

• www.unc.edu

• Departments

• Divisions

• Schools

• Campus Units

• Centers

• Institutes

• Research Labs

• Programs

• Collaborations

• Student Organizations

• Greek Community

• Instructional

Resources

• Services

• Faculty CVs

• Portfolios

And Much, Much

More!

What Kind of Sites?

How big is “big”?

8,500 Sites

77,000

Users

How big is “big”?

243 Themes

140 Plugins

Infrastructure

Varnish• Bypassed for logged in users• Cache purging handled via custom plugin

3 Apache Webservers

NFS mounted shared file system • WordPress Core, themes, plugins, uploads, etc

2 MySQL servers • Replication/Hot spare• Full DB backups daily with point-in-time recovery

available from binary logs

Our Setup:

InfrastructureOngoing Challenges/Lessons:

Varnish• Cache invalidation is hard

NFS• A single file system is simple, but not as fast

Apache• You should probably just should use NGINX

Database• Our databases are huge• Explore using HyperDB, or purge unused sites/tables/rows

Plugins & Themes

“I’ll just use this plugin”

http://devpractic.es/post/98877425141/ill-just-use-this-plugin

Selecting Themes & PluginsLicensing

• GPLv2 or compatible?• Per Domain?

Updates & Notifications• Wordpress.org vs External Repositories• Notifications only when activated

Things to Watch Out For• SHOW TABLES LIKE• switch_to_blog()• get_plugins()• eval()

WordPress.com VIP standards• http://vip.wordpress.com/documentation/code-review-what-we-

look-for/

Selecting Themes & PluginsOngoing Challenges/Lessons:

Size of the codebase• Keep it simple• Only add what you truly need

Deprecate old plugins and themes• Over 2 years since last update? Find a replacement

Be picky about your plugins and themes• Thoroughly review the code• Is it in active development?• How is the support?

Security

Single Site = Multisite

No FTP

Thoroughly Review Themes & Plugins

Super Admins• Limit who/how many• Set them in code with an MU Plugin

Update, Update, Update!

Security

Tools!Splunk• Insight into your logs

• Reporting, Alerts, etc.

• We use for PHP, Apache & ModSecurity

• Free version lets you index up to 500MB of data per day

Tools!AppDynamics• Service monitoring

• Average response times

• Full call stack

• Free version stores data for last 24 hours

Tools!AppDynamics

Tools!AppDynamics

Tools!Query Monitor• Built by John Blackbourn, current WP 4.1 development

lead

• Deep insight into each page load

Multisite Specific Plugins• Multisite Plugin Manager

• Multisite Privacy Plugin

• WordPress MU Domain Mapping

• Network Manager Tools

Tools!Version Control• Git - Stash (Atlassian)• Full infrastructure builds of wp-content directory• Custom & 3rd party Themes/Plugins handled via

submodules

Local Development with Vagrant• Customized version of VVV Apache• Builds out 3 multisite environments

PHPStorm• PHP Storm 8 has full WordPress support• Xdebug• Database Connections• Version Control

TakeawaysKeep it simple!• Use as few themes/plugins as you truly need

• For open network, find add-ons that get your users 90%

there

Think long term• Each decision you make will affect a lot of sites/users

down the road

• The longer something is in place, the harder it is to change

Questions?