A Technique for User Specific Request Redirection in a Content Delivery Network

This paper presents a technique for user specific request redirection for personalizing responses to user requests in Content Delivery Networks. User specific request redirection refers to the process of redirecting user requests to a server on the content delivery network based on user specific information carried in the request. Current schemes for redirecting user requests to a content delivery server in a Content Delivery Network are either based on the authoritative DNS model or the URL rewrite model. The authoritative DNS model is not flexible to support user specific request redirection as user specific information is not available to the DNS server; the URL rewrite model cannot support user specific redirection in practice because of the cost of on-the-fly rewrites that is required on per user basis for it to be truly flexible. Our technique, which we refer to as Request Deflection, allows for flexible user specific request redirection. We show the advantage of the technique using experimental data as well as empirical data from current content providers. The technique is simple enough to be implemented at wire-speed in a switch.