Service Discovery in a Grid-based Peer-to-Peer Architecture

Peer-to-Peer systems can provide an effective e-business solution and a rich communication medium for work groups in University Campus, Research Lab, Enterprise, Finance environments. The need for coordinated resource sharing and problem solving in large, multi-institutional Virtual Organizations is also the strong motivation behind Grid Computing, which is more concerned on security than Peer Computing but appears quite inflexible for highly dynamic, massive communities. In our opinion, to fulfil the requirements of community-oriented applications it is necessary to combine elements of both paradigms. In this paper we illustrate the first steps in the design and development of a service-oriented P2P architecture based on the concept of stateful Web Service, i.e. a Grid Service, a network-enabled entity that provides some capabilities. In order to better support highly dynamic scenarios, service providers publish their services as XML advertisements which are then exploited by peers in the discovery phase.