User Specific Request Redirection in a Content Delivery Network

Abstract

This paper discusses user specific request redirection for personalizing responses to user requests in Content Delivery Networks (CDN). 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 user request. Current redirection schemes in CDNs are either based on the authoritative DNS model or the URL rewrite model. The authoritative DNS model is not flexible to support user specific 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 URL rewrites required on a per user request basis. We discuss a technique that allows for flexible user specific request redirection. The technique is simple enough to be implemented at wire-speed in a switch.