EFFICIENT ALGORITHMS FOR WEB SERVICE COMPOSITION

Abstract

With the popularity of Internet technology, web services are becoming the most promising paradigm for distributed computing. However, when a single web service fails to meet service requestor's multiple function needs, web services need to be dynamically configured together to form a web service composition. This thesis proposes a special data structure for storing web services. Normally web services are stored in inverted data tables in UDDI registry. In the thesis web services are stored in web services chain data structure which describes the dependent relations among - web services, is proposed, and an efficient algorithm for WS composition is developed based on the data structure. Experiments are carried out in order to compare the performance of the algorithms with different data structure. This thesis proposes Bi-Directional Dijkstra's algorithm for web service selection, which is based on the sorted function graph. With the graph model, it converts the problem to a multi-constraint optimal path problem in the graph theory. The optimal composite services can be constructed with meeting the QOS constraints. Experiments are carried out in compare the performance of runtime with dijkstra algorithm