Akamai also has a decent list of publications that provide some insight on how they do things: http://www.akamai.com/html/perspectives/techpubs.html

I recommend the following from that list: * Keeping Track of 70,000+ Servers: The Akamai Query System * Improving Performance on the Internet * The Akamai Network: A Platform for High-Performance Internet Applications * Scaling a Monitoring Infrastructure for the Akamai Network