Using graph grammars for interaction style description: applications for service-oriented architectures

Applications with run-time changing architectures constitute a challenge for both modelling and reasoning. Their description is not limited to the specification of a unique static topology but must cover the scope of all the correct configurations. We develop, in this paper, the concept of architectural styles to achieve this goal. We elaborate and specify the basic architectural styles for the design of service-oriented applications. For this purpose we develop an appropriate formal framework using graph grammars. Our approach enables both generating architectures in conformance with a given style and checking conformance of ad-hoc architectures. We first, describe formally the basic interaction style involving elementary interactions between a service requestor and a service provider. Then we consider the orchestrated interaction style where an orchestrator manages the workflow of several service requestors and providers. Finally, we define a complex architectural style to address the compositional aspect of service-oriented architectures considering composite services. We also provide rules for composing the previous styles to define the composite basic invocation style and the composite orchestrated style.