Using PVS for Modeling and Verifying Cloud Services and Their Composition

Cloud computing enables one to access applications through Internet, without explicitly installing them on one single computing device. Formal modeling and verification of cloud services and their composition is fundamental to guarantee the accurate working and availability of cloud applications. In this paper, we use the Prototype Verification System (PVS) for formal modeling and verification of cloud services. Cloud services are modeled in PVS with the combination of logical predicates that represent the relations among the timed data sequences being observed at its input and output ports. Furthermore, composition operators are modeled that can be used to combine different cloud services together to construct more complex services. With our approach, properties of cloud services and refinement relations between different cloud services can be formalized as goals and proved with the PVS proof assistant.