The Networked Resource Discovery Project

Large scale computer networks provide access to a bewilderingly large number and variety of resources, including retail products, network services, and people in various capacities. We consider the problem of allowing users to discover the existence of such resources in an administratively decentralized environment. We describe an approach for a system that accesses the distributed collection of repositories that naturally maintain resource information, rather than building a global database to register all resources. A key problem is organizing the resource space in a manner suitable to all participants. Rather than imposing an inflexible hierarchical organization, our approach allows the resource space organization to evolve in accordance with what resources exist and what types of queries users make. Concretely, a set of agents organize and search the resource space by constructing links between the repositories of resource information based on keywords that describe the contents of each repository, and the semantics of the resources being sought. The links form a general graph, with a flexible set of hierarchies embedded within the graph to provide some measure of scalability. The graph structure evolves over time through the use of cache aging protocols. Additional scalability is targeted through the use of probabilistic graph protocols. A prototype implementation and a measurement study are under way. hhhhhhhhhhhhhhhhhh 1 This material is based upon work supported in part by the National Science Foundation under Cooperative Agreement DCR-84200944, and by a grant from AT&T Bell Laboratories.