OWL-S based Web service discovery in distributed system

Web services are the new paradigm for distributed computing. A critical factor to the overall utility of Web services is a scalable, flexible and robust discovery mechanism. Currently Web Service systems, which publish WSDL-described Web Services in UDDI, cannot support automatic Web Service publication, discovery and execution. Traditional centralized indexing scheme can't scale well with a large distributed system. In this paper, we present a service discovery model for building dynamic, scalable, decentralized registries with flexible search capabilities, to support Web service discovery. In our work, we focus on a fully distributed architecture motivated by recent advances in a two-layer P2P network topology without a need for centralized service registries. Furthermore, the OWL-S ontology is used to add semantics to the Web Service descriptions and then register them on a specific registries peer in the P2P environment according to the service's domain ontology. The experiments show that the discovery model has good scalability and the semantic annotation can notably improve discovery exactness. The improved algorithms can discover the most potential service against request.