An Approach to Monitor Scenario-Based Temporal Properties in Web Service Compositions

Keeping composite services satisfying desired properties has been widely accepted as an important and challenging problem due to the dynamically evolving attribute of web service compositions. Runtime monitoring and dynamic verification techniques become first class activities to be performed during the execution of web service compositions. Scenario-based temporal properties depicting the complex interactions among the different services are a kind of important property which needs to be monitored at runtime. However, some complex scenario-based temporal properties cannot be easily represented by the traditional formalism such as temporal logic. In this paper, we first propose to represent the scenario-based temporal properties of web service compositions by the use of a novel notation (Property Sequence Chart). Then, we use Aspect-Oriented Programming techniques to extend the open-source BPEL engine (ActiveBPEL) and monitor its execution. Based on these assumptions, we propose a more intuitive approach to monitor the scenario-based temporal properties in web service compositions.