Reverse Engineering the Youtube Video Delivery Cloud

In this paper we set out to “reverse-engineer” the YouTube video delivery cloud by building a globally distributed active measurement infrastructure. Through careful and extensive data collection, analysis and experiments, we deduce the key design features underlying the YouTube video delivery cloud. The design of the YouTube video delivery cloud consists of three major components: a “flat” video id space, multiple DNS namespaces reflecting a multi-layered logical organization of video servers, and a 3-tier physical cache hierarchy. By mapping the video id space to the logical servers via a fixed hashing and cleverly leveraging DNS and HTTP redirection mechanisms, such a design leads to a scalable, robust and flexible content distribution system.