CS654 Project Report Critical Examination of Service Discovery Techniques in Peer-to-Peer Systems

Web services are the new paradigm of distributed computing because of their promise toward interoperability of applications and integration of large scale distributed systems. On the other hand, with the ever increasing number of computers all around the globe, peerto-peer(P2P) networks have gained large popularity capitalizing on their open, distributed, inter-operable, cost-effective and resource-friendly nature. As a consequence, the problem of finding a way to effectively combine web services with P2P technologies has gained much attention because of its potential to be an effective solution to business integration problems. Hence, different large-scale service infrastructures utilizing P2P systems have been proposed by many research groups. Service discovery, an integral part of any large-scale service infrastructure, ensures that all the services provided by different providers within the infrastructure are collected, organized and published in a way that the clients can efficiently search and find their desired services. Due to the transitory nature of peer population and ever-changing information content in these peers, users almost always do not have the exact information about the available services/resources in the system. As a result, queries are based on partial information requiring a flexible search mechanism which, by the way, also have to be complete, scalable and efficient. Existing search mechanisms in P2P networks, in general, do not provide a satisfactory solution for achieving the conflicting goals of flexibility and efficiency. Unstructured search techniques sacrifice efficiency for flexibility, whereas structured ones (mostly