Mirroring Resources in the World Wide Web

One of the main problems faced by the users of the World Wide Web is that of a broken link in a hypertext, normally caused by the unavailability of a particular resource. The introduction of redundancy is the key mechanism to solve this problem. Unfortunately, the current infrastructure of the Web is based on a resource identification scheme that maps a resource identifier on a unique physical location; this scheme does not favour the implementation of a support for the replication of Web resources. In this paper we discuss how URNs (Uniform Resource Names), a resource identification scheme proposed by a special work group of the Internet Engineering Task Force (IETF), can be employed to implement a support for the mirroring of Web resources. Our proposal is based on the implementation of a proxy and a gateway that together allow conventional browsers and servers to access and manage mirrored resources transparently, allowing the provision of highly available Web resources.