Semantics-based Efficient Web Service Discovery and Composition

Service-oriented computing is gaining wider acceptance.F or Web services to become practical, an infrastructure needs to be sup ported that allows users and applications to discover, deploy, compose and syn thesize services automatically. For this automation to be effective, formal se mantic descriptions of Web services should be available. In this paper we formall y define the Web service discovery and composition problem and present an ap pro ch for automatic service discovery and composition based on semantic d es ription of Web services. We also report on an implementation of a semantics -based automated service discovery and composition engine that we have devel oped. This engine employs a multi-step narrowing algorithm and is efficiently implemented using the constraint logic programming technology. The salient f a ures of our engine are its scalability, i.e., its ability to handle very large s ervice repositories, and its extremely efficient processing times for discovery and comp sition queries. We evaluate our algorithms for automated discovery and compos ition on repositories of different sizes and present the results.