Scaling WordPress on Amazon Web Services

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What This Talk Will Cover

  • Theory & Concepts
  • Planning
  • Step-by-step Example
  • Deployment
  • Pricing
  • Q&A

About Me

Russell Heimlich on a pogo stick in a suit

I’ve been playing with WordPress since 2007

Screenshot of Russell Heimlich's first blog post

Lead Developer at

Billy Penn The Incline

When I’m not coding…

Zadie wearing a WordPress onesie

A Familiar Story…

We lasted 15 minutes…

How can we build a website that scales?

What is Scaling?

Scal•a•bil•ity—the capability of a system, network, or process to handle a growing amount of work

via Scalability on Wikipedia

Horizontal Scaling

Vertical Scaling

  • Bigger Servers
  • Adding a CDN
  • Redis/Memcache

Pets vs. Cattle

Pets

  • Cutesy Names like Brutus, Penelope, Jenny
  • Unique, loving, cared for
  • When ill, you fix them

Cattle

  • Algorithmic names like ec18453ba, h65106z, 8675309
  • Nearly identical to other cattle
  • When ill, you replace them

Pets don't scale!

What is high availability?

Websites have many components

Achieving High Availability

  • Redundancy to reduce single points of failure
  • Graceful failover
  • Monitoring/alerts + automation
Nines Availability Downtime per Year
1 90% 36.5 days
2 99% 3.65 days
3 99.9% 8.76 hours
4 99.99% 52.56 minutes
5 99.999% 5.26 minutes
6 99.9999% 31.5 seconds
7 99.99999% 3.15 seconds
8 99.999999% 315.569 milliseconds
9 99.9999999% 31.5569 milliseconds

Planning

Do Your Homework!

  • What isn't working on your current host?
  • What is working?
  • What are the specs of your current host?
  • CPU and RAM usage?

Traffic Analysis

  • What was your busiest hour via Google Analytics?
  • Figure out how many requests per second that was
  • What type of page was that peak? Homepage? Article?
  • Bandwidth reports from current host?

Yearly Traffic Spikes

Pageviews by hour

13,322 pageviews per hour

÷ 60 minutes

÷ 60 seconds

= 3.70 pageviews per second

58 requests per pageview

x 3.70 pageviews per second

= 214.6 requests per second

What is Amazon Web Services?

Range of cloud services charged based on usage with no upfront costs.

Let's Build a Website Infrastructure from Scratch!

Pick a Region

Regions & Availability Zones

Regions are separate geographic area

Regions have multiple, isolated availability zones

Add a Server

Elastic Compute Cloud (EC2)

Amazon Virtual Servers

Launch a machine to connect to and install software on

What size server?

  • Stick with the T2 general purpose instances
  • Start small (t2.micro) and upgrade as needed

See 5 Steps for Finding Optimal EC2 Infrastructure

Add a Database

Relational Database Service (RDS)

Amazon SQL

Managed MySQL database

Add a Redis Caching Layer

Elasticache

Amazon Redis

Managed Redis/Memcached service

Add a 2nd Server

Add a Load Balancer

Add an S3 Bucket

Simple Storage Service (S3)

Amazon Unlimited FTP Server

Upload and serve static files from

SSL and S3 Buckets

  • Bucket names should be DNS compliant
  • Lower-case letters, numbers, hyphens

BAD: example.com.s3.amazonaws.com

GOOD: example-com.s3.amazonaws.com

Availability Zones and Autoscaling

Availability Zones and Autoscaling

Availability Zones and Autoscaling

Add a CDN

Amazon CloudFront

Amazon CDN

KeyCDN ($0.04/GB) vs CloudFront ($0.08/GB)

Software

Pick an Amazon Machine Image (AMI)

Ubuntu Server 14.04 LTS (HVM), SSD Volume Type (64-bit)

Configuring a Server

Use EasyEngine.io

wget -qO ee rt.cx/ee && sudo bash ee
sudo ee site create example.com  \
	--wpsubdomain \
	--wpredis \
	--php7 \
	--user=admin \
	--pass=admin

* Requires Ubuntu or Debian OS

EasyEngine will install the following components + dependencies

  • nginx
  • PHP 7
  • WordPress Multisite with Subdomains
  • Full page caching using Redis

s3cmd

Create an AMI of your Server

Use this image to launch new instances

WordPress Plugins

nginx Helper

  • Purges Redis cache based on WordPress events
  • Installed automatically by EasyEngine

WP Redis

  • Tells WordPress to use Redis for object caching
  • After installation, copy object-cache.php to /wp-content/
  • Add Redis configuration to wp-config.php
    $redis_server = array(
  'host' => 'redis-xxxxxxxxxx.amazonaws.com',
  'port' => 6379,
);

WP Offload S3 Lite

  • Syncs uploaded media to S3
  • Rewrites uploaded media URLs to be served by S3 or a CDN

Load Testing

Apache Benchmarking (ab)

  • Free
  • Downloadable tool
  • Run on your own computer

loader.io

  • Free Plan
  • 10,000 clients / test
  • In the cloud

Amazon Cloudwatch

Deployment

Because sometimes you need to change things

Pricing

~$220 per Month

Reserved Instances

  • Billing concept
  • Reduced hourly rate
  • Commitment to reserve resources

Free Tier

Other Resources

Wrapping up!

  • AWS offers a lot of flexability…
  • …at the cost of complexity
  • Maybe cheaper?
  • A valuable skill to have

Thank You!

Tweet me! @kingkool68

Questions?