© 2015, Amazon Web Services, Inc. or its Affiliates. All rights reserved.

Alex Dunlap

GM, Amazon CloudFront

Jarrod Guthrie

Sr. Product Manager, Amazon CloudFront

Calin Nemes

Sr. Support Engineer, Amazon CloudFront

Matthew Baldwin

Sr. Software Development Engineer, Amazon CloudFront

October 2015

Using Amazon CloudFront to Improve

Performance, Availability and Cacheability

STG206

What to expect from the session

• Best practices for setting up your origin

• Gaining visibility into your distribution

• How to improve cacheability

• How to test your configuration

Best practices for setting up

your origin

Following origin best practices can give you…

Easier debugging

Better performance

Higher availability

Five best practices

1. Use Amazon Route 53 health checks and DNS failover

2. Configure multiple origins

3. Secure your origin

4. Log request IDs

5. Set origin response headers

Failover

Only return answers for resources

that are healthy and reachable

from the outside world, so that

your end users are routed away

from a failed or unhealthy part of

your application

Health Checks

Automated requests sent over

the Internet to your application

to verify that your application is

reachable, available, and

functional

+

Amazon Route 53 health checks and

DNS failover

Use Route 53 to improve availability & performance

Use Route 53 to improve availability & performance

Use Route 53 to improve availability & performance

Use Route 53 to improve availability & performance

Use Route 53 to improve availability & performance

eu-west-1

Configure multiple origins

Elastic Load

Balancing

Dynamic content

Amazon EC2

Static content

Amazon S3

*

(default)

/error/*

/assets/*

Amazon CloudFront

example.com

Access control: Restricting origin access

Amazon S3

Origin Access Identify (OAI)• Prevents direct access to your Amazon

S3 bucket

• Ensure performance benefits to all

customers

Custom origin

Block by IP address• Whitelist only the Amazon CloudFront

IP Range

• Protects origin from overload

• Ensure performance benefits to all

customers

Object Access Identity (OAI)

• Ensure only Amazon CloudFront

can access Amazon S3 bucket

• We make it simple for you

Amazon CloudFront

Region

Amazon S3

bucket

Custom origin

Object Access Identity (OAI)

• Ensure only Amazon CloudFront

can access Amazon S3 bucket

• We make it simple for you

Amazon CloudFront

Region

Amazon S3

bucket

Custom origin

Shield custom origin

• Shield your custom origin

• Whitelist Amazon CloudFront IP rangeAmazon CloudFront

Region

Amazon S3

bucket

Custom Origin

Shield custom origin

• Shield your custom origin

• Whitelist Amazon CloudFront IP rangeAmazon CloudFront

Region

Amazon S3

bucket

Custom origin

Shield custom origin

• Subscribe to Amazon SNS notifications on changes to

IP ranges

• Automatically update security groups

AWS Lambda

Amazon CloudFront

Amazon SNS

Security group

Web app

server

Web app

server

AWS IP ranges

Update IP rangeSNS message

Log Amazon CloudFront request IDs at origin

Nginx:

log_format main '$remote_addr - $remote_user [$time_local] "$request" ‘ '$status $body_bytes_sent "$http_referer" ‘ '"$http_user_agent" http_x_forwarded_for" "$http_x_amz_cf_id"';

Apache:

LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" \"%{X-Amz-Cf-Id}i\"" combined

Set origin response headers

*Strict-Transport-Security: max-age=15552000;

*X-Frame-Options: SAMEORIGIN

*X-XSS-Protection: 1; mode=block Options

*Cache-Control: max-age=300; public

Demo

Key takeaways

• Use Amazon Route53’s health checks and DNS failover

• Improve security by setting headers at your origin

• Enable logging

• Serve your static assets on Amazon S3

• Serve error pages from Amazon S3

Gaining visibility into your distribution

Visibility into your distribution

Four different ways to get visibility:

• AWS CloudTrail – for monitoring distribution config changes

• Near real-time metrics – Provided by Amazon CloudFront

• Amazon CloudFront reports – for analytics

• Amazon CloudWatch Logs – for custom monitoring

Monitor distribution config changes

• Monitor changes to distribution configuration using

AWS CloudTrail

• Get alarms when:

• Distribution is disabled

• Trusted signers are disabled

• Custom TLS certificate changes

Amazon CloudFront near real-time metrics

• Provided in near real-time

• Via Amazon CloudWatch

• Alarm on 6 metrics:

• Requests

• Bytes downloaded

• Bytes uploaded

• 4XX error rate

• 5XX error rate

• Total error rate

Amazon CloudFront reports to identify trends

• Cache hit/miss

• Incomplete downloads

• Top countries

• Mobile users

• Popular objects

Generate custom metrics

• Amazon CloudFront access logs

• Delivered via Amazon Kinesis to Amazon S3 buckets

• Typically within an hour of an event happening

Edge locationAmazon

S3

Edge location

Edge location

Generate custom metrics

• Upload logs to Amazon CloudWatch using AWS Lambda

Amazon

CloudFront

Amazon

S3

AWS

LambdaAmazon

CloudWatchAlarm

Keywords e.g. Bots Granular Response Code e.g. 4XX Request to certain URLs TLS versions

Demo

Key takeaways

• Enable AWS CloudTrail

• Monitor your Amazon CloudFront reports

• Create alarms

• Subscribe to Amazon CloudFront access logs

• Push logs to Amazon CloudWatch

How to improve cacheability

Improving cacheability of your objects

• Versioning website assets

• Cache headers

• Shared distribution

• Forwarded values

• Path prefix invalidations

Versioning website assets

<link

href="//assets.example.com/assets/v1/css/jumbotron-narrow.css“rel="stylesheet">

<link

href="//assets.example.com/assets/v2/css/jumbotron-narrow.css“rel="stylesheet">

<link

href="//assets.example.com/assets/css/jumbotron-narrow.css?<md5sum>“rel="stylesheet">

Cache-Control & expires

< Cache-Control: max-age=300

< Cache-Control: max-age=30, s-maxage=3000

< Expires: Thu, 18 Sep 2025 21:34:50 GMT

Min TTL Default TTL Max TTL

Set min, max and default TTL on Amazon CloudFront

Cache-Control & expires

*.css, *.js or Images

Cache-Control: public; max-age=31536000

index.html

Cache-Control: no-cache=Set-Cookie; max-age=30

Live streaming

/*.m3u8 => Cache-Control: public; max-age=2

Shared distributions

• Shared assets across multiple properties

Static content

Amazon S3

Amazon CloudFront

assets.example.com

www.example.com

www.example.org

Forwarded values

• Check forwarded headers

• Query string forwarding

• Cookie forwarding

• Trusted Advisor checks

Invalidations

• Last resort

• Only applies to Amazon CloudFront cache, not browsers or

intermediary caches

Demo

Key takeaways

• Use versioning

• Use multiple cache behaviors

• Forward only required headers

• Use invalidations as last resort

How to test your configuration

Test your configuration

• Test in development mode

• Ensure content is cached correctly

• Performance testing

• Load testing

• Test SSL configuration

Turn on development mode

• Set maximum TTL to 0

• Without need to constantly invalidate!

• Forwarding all headers changes behavior

• Whitelist your IP using AWS WAF so only

accessible from corporate network

• Signed cookies

Ensure content is cached correctly

Check cache/hit miss ratio of distribution on reports

Developer console on Chrome or Firefox

• Age header

• X-Cache

• Cache-Control headers

• HSTS headers

Performance testing

Backbone testing Last mile testing Real user testing

Load testing

Traditional load testing

• Use one client

• From a single region

• Hits single IP

DNS load balancing

Simulate real user environment

Ideal load testing

• Clients from multiple locations

• Independent DNS requests

• Distribute across IPs

DNS load balancing

Simulate real user environment

SSL labs

• Verify your SSL config

Demo

Key takeaways

• Switch off caching during development mode

• Use RUM for performance testing

• If you load test - test from multiple locations

Thank you!

Remember to complete

your evaluations!

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