VerChor: A Framework for Verifying Choreographies

Nowadays, modern applications are often constructed by reusing and assembling distributed and collaborating entities, e.g., software components, Web services, or Software as a Service in cloud computing environments. In order to facilitate the integration of independently developed components (i.e., peers) that may reside in different organizations, it is necessary to provide a global contract to which the peers participating in a service composition should adhere. Such a contract is called choreography, and specifies interactions among a set of services from a global point of view. This contract is the reference for the further development steps (service selection, code generation, maintenance, reconfiguration, etc.). The specification and formal analysis of this contract is therefore crucial and must be handled carefully by the designer to avoid an erroneous design, which would be very costly if discovered lately in the development process. Unfortunately, only limited effort, e.g. [3,6,1], has been spent to develop formal verification tools, which can automatically detect issues such as deadlocks or erroneous behaviours in the choreography specification. In this paper, we propose a modular framework for performing automatically a number of crucial verification tasks on choreography specifications. Our framework accepts as input the following interaction-based choreography description languages: (i) XML-based languages (WS-CDL), (ii) graphical notations (BPMN 2.0 choreographies), and (iii) formal description models (Chor, conversation protocols). In order to favour extensibility and reusability of our framework, we