1. CS193H: High Performance Web Sites Lecture 6: Use a CDN Steve Souders Google souders@cs.stanford.edu

2. Announcements

3. Rule 2: Use a CDN Content Delivery Network geographically distributed servers => closer to your users also: backups, storage, caching, absorb spikes Akamai, Mirror Image, Limelight, Savvis new: Amazon S3, Panther Express (more affordable) dynamic content: 1 HTTP request, static content: all the rest distribute your static content before distributing your dynamic content http://stevesouders.com/examples/ex-cdn.php

4. CDN – reverse proxy Edge Servers Origin Server(s) Developer User name server ISP's DNS Resolver 198.87.82.45 CDN

5. CDN Usage CDN www.aol.comAkamai www.ebay.comAkamai www.facebook.comAkamai www.google.com/search search.live.com/resultsAkamai www.msn.com www.myspace.comAkamai en.wikipedia.org/wiki www.yahoo.com www.youtube.com

6. Homework CSS sprites and data: URLs on your "Improving Top Site" class project Test improvements using Hammerhead record results in your personal Web 100 sheet read Chapter 3 of HPWS

7. Questions What's the most important requirement for a CDN? How can you find out which CDN a company uses? What plays the key role in sending users to the appropriate edge server?