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Globally Distributed Content Delivery. Presenter: Baoning Wu 03/25/2003. Motivation. Flash crowd problem Overload can crash web sites and cause high response time Akamai’s system. Akamai’s network infrastructure.
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Globally Distributed Content Delivery Presenter: Baoning Wu 03/25/2003
Motivation • Flash crowd problem • Overload can crash web sites and cause high response time • Akamai’s system
Akamai’s network infrastructure • Allocate more servers to sites experiencing high load and serve all clients from nearby servers. • The system directs client requests to the nearest available server likely to have the requested content.
How to find servers? • Dynamic DNS system
Criteria for name servers to resolve IP address • Service requested • Server health • Server load • Network condition • Client location • Content requested
DNS resolution • A7.g.akamai.net • Root name server -> • .net name server -> • .akamai.net name server(top level)-> • .g.akamai.net name server(low level)
Network services • Static content • Use cache, apply lifetime • Dynamic content • Assemble dynamic content on edge server • Streaming media • Windows Media, Real, Apple’s QuickTime
Challenges • Scalability • Must scale to many distributed servers • Reliability • Both hardware and software • Software deployment • Deploy new network software in stages
Challenges (continue) • Content visibility and control • Cache consistency • Lifetime control • Authentication and authorization • Integrity control • Visibility into access patterns • billing