Property Patterns for Runtime Monitoring of Web Service Conversations

For a system of distributed processes, correctness can be ensured by statically checking whether their composition satisfies the properties of interest. However, web services are distributed processes that dynamically discover properties of other web services. Since the overall system may not be available statically and since each business process is supposed to be relatively simple, we propose to use runtime monitoring of conversations between partners as a means of checking behavioral correctness of the entire web service system. Specifically, we identify a subset of UML 2.0 Sequence Diagrams (SD) as a property specification language. We show how our language can be used to specify the patterns in the Specification Property System (SPS) [1]. By formalizing this subset using automata, we can check finite execution traces of web services against various complex properties. Finally, we discuss our experience using our language for runtime monitoring of an existing application, and conclude with a description of existing tool support.