SEMREG-Pro: A Semantic based Registry for Proactive Web Service Discovery using Publish-Subscribe Model

Service discovery is vital for the expansion of Web services and is often identified as one of the most challenging problems for the wide-scale use of Web services. As the number of Web services is increasing on the Web, service discovery is becoming a major issue. To address this issue, UDDI registry has been developed by standard bodies. However, the challenge is no longer in providing information anytime, anywhere but in providing precise and accurate information to the users in real time. UDDI lacks in these characteristics because searching mechanism of UDDI is based on keyword matching. Service discovery is limited to service name and classification. Current registry-based approach for service discovery is a passive style registry, which essentially provides service information in response to a request. There is no way to push information towards service users. In this paper, we propose a proactive registry for efficient discovery that utilizes semantic-based publish-subscribe model. We use proactive push approach for providing service notifications to service requester and semantic based capability matching of OWL-S Web service descriptions. The algorithm assigns scores to individual concepts of the advertised service by concept matching with that of the requested one and then assigns overall ranking to advertisement on the basis of individual scores. The results show a significant increase in precision and recall of service discovery as compared to UDDI approach and other semantic based approaches.