An Integrative Approach for Attaching Semantic Annotations to Service Descriptions

Service discovery in large scale, open distributed systems is difficult because of the need to filter out services suitable to the task at hand from a potentially huge pool of possibilities. Semantic descriptions have been advocated as the key to expressive service discovery, but the most commonly used service description and registry protocols do not support such descriptions in a general manner. In this paper we present an approach (and implementation) of service registry and discovery that uses an rdf triple store to integrates the major service descriptions (wsdl, uddi, and daml-s) and other, taskor even userspecific metadata that can be used for service discovery. Our approach allows us to present multiple interfaces (compatible with all the above approaches and others) so that services registered through one interface are available to be found via the other interfaces. Furthermore, we provide ways of extending these interfaces to attach other structured metadata, and search across it and all of the structures in the component models. The result is an extremely flexible service registry that can be used asis with existing standards, or as the basis of a far more sophisticated semantically-enhanced service discovery engine.