WSExpress: A QoS-aware Search Engine for Web Services

Web services are becoming prevalent nowadays. Finding desired Web services is becoming an emergent and challenging research problem. In this paper, we present WSExpress (Web Service Express), a novel Web service search engine to expressively find expected Web services. WSExpress ranks the publicly available Web services not only by functional similarities to users’ queries, but also by nonfunctional QoS characteristics of Web services. WSExpress provides three searching styles, which can adapt to the scenario of finding an appropriate Web service and the scenario of automatically replacing a failed Web service with a suitable one. WSExpress is implemented by Java language and large-scale experiments employing real-world Web services are conducted. Totally 3,738 Web services (15,811 operations) from 69 countries are involved in our experiments. The experimental results show that our search engine can find Web services with the desired functional and non-functional requirements. Extensive experimental studies are also conducted on a well known benchmark dataset consisting of 1,000 Web service operations to show the recall and precision performance of our search engine.