Signature-Based Composition of Web Services

The Web services family of standards promotes the interoperability of heterogeneous distributed systems by separating the definition of a service from, 1) its implementation language, 2) its internal data representation, and 3) the communication protocol used to access it. The UDDI standard addresses aspects related to the publication and querying of enterprise business services, but the kind of representation that is supported, and the corresponding queries have limited functionality. We are interested in the problem of querying a UDDI registry with a functional specification of a service, and getting in return a single service, or a composition of services that address the functional need. Existing approaches to Web service composition rely on external semantic knowledge to identify candidate component services. Our approach relies on service signatures (message types). We describe the principles underlying our approach, a family of algorithms for Web service composition, our implementation of these algorithms, and the preliminary experimental results.