Automated synthesis of local time requirement for service composition
This work addresses time-critical service composition for businesses relying on service level agreements, though it appears incremental as it builds on existing BPEL modeling.
The paper tackles the problem of ensuring composite services meet global response time requirements by automatically synthesizing local time constraints for component services, using an extended BPEL model with formal semantics, and validates the approach with a tool called Selamat.
Service composition aims at achieving a business goal by composing existing service-based applications or components. The response time of a service is crucial especially in time critical business environments, which is often stated as a clause in service level agreements between service providers and service users. To meet the guaranteed response time requirement of a composite service, it is important to select a feasible set of component services such that their response time will collectively satisfy the response time requirement of the composite service. In this work, we use the BPEL modeling language, that aims at specifying Web services. We extend it with timing parameters, and equip it with a formal semantics. Then, we propose a fully automated approach to synthesize the response time requirement of component services modeled using BPEL, in the form of a constraint on the local response times. The synthesized requirement will guarantee the satisfaction of the global response time requirement, statically or dynamically. We implemented our work into a tool, Selamat, and performed several experiments to evaluate the validity of our approach.