Transferring transactional business processes to FaaS

Function-as-a-Service (FaaS) is a modern cloud service model that has gained significant attention from the research and industry communities in recent years for its many benefits such as dynamic scaling, cost efficiency, faster programming, flexibility to microservices and containers technology. However, the building and deployment of serverless applications come with many challenges that need to be tackled, like workflow design complexity and migration of other applications. When transactions between different parties are involved, the workflow becomes knotty and the communication between participants and all properties of transactions have to be properly resolved. Transactions have widely been discussed in Business processes, so same practices might be adopted by serverless workflows. In this work we provide guidelines and mapping mechanisms for transforming transactional Business Process Modeling Notation 2.0 (BPMN2) applications to a serverless platform. We shed light on the current inability of function orchestrators to express workflow definitions, and deal with various architectural dilemmas that stem from the dissimilar nature of stateful BPMN vs. stateless serverless applications. We overcome the unbalanced capabilities between well-established BPMN notations and function orchestration definitions and illustrate how to exploit and combine cloud native services that comes with FaaS to create serverless applications.