Semantic Web Services Monitoring: An OWL-S Based Approach

In this paper we describe mechanisms for execution monitoring of semantic Web services, based on OWL-S. The use of semantic descriptions and ontologies is a valuable extension to current SOA conceptualizations. The described mechanisms are implemented as extensions of the OWL-S virtual machine that we have previously developed. The OWL-S virtual machine is a component that controls the interactions between a client and the Web service it uses. The presented extensions are a result of practical requirements that arose in the course of involvement with two projects that utilize OWL-S based semantic Web services. In particular, we present an event-based model for monitoring and logging interactions. The interaction trace allows a human or software agent to analyze, replay or debug the execution. Additionally, we describe proposed extensions to current specification in OWL-S for reporting and handling of errors. Finally, we describe extensions to the OWL-S virtual machine based on introspection to enable dynamic interactions with process mediators.