On the modularity and reusability of the rule-based specification of QoS properties of systems
Francisco Durán, Steffen; id_orcid 0000-0001-9062-6637 Zschaler · Research Portal (King's College London) · 2012
An interaction is an action by which communicating processes can influence each other.Interactions in the time of Web are something more than input and output between two entities.Actually, the word itself can be misleading, by suggesting a reciprocal or mutual kind of actions.Instead, interactions more and more often involve many parties and actions are difficult to classify under output and input primitives.In the field of process calculi, the best studied, well-understood and popular form of interaction is dyadic, i.e., where only two processes are involved.As networks have become part of the critical infrastructure of our daily activities (for business, home, school, social, health, news, government, etc.) and a large variety of loosely coupled processes have been offered over global networks, as services, more sophisticated forms of interactions have become common, for which convenient formal abstractions are under study.For example, one important trend in networking is moving towards architectures where the infrastructure itself can be manipulated by the software, like in the Software Defined Networking (SDN) approach, where the control plane is remotely accessible and modifiable by software clients, using open protocols such as OpenFlow, making it possible to decouple the network control from the network topology and to provide Infrastructure as a Service (IaaS) over data-centers and cloud systems.In this talk, we propose a process calculus abstraction based on Open Multiparty Interaction instead of ordinary Dyadic Interaction.An interaction is multiparty when it involves two or more processes and it is open when the number of involved processes is not fixed or known a priori.Despite the inherent complexity of representing more sophisticated forms of interaction, we show that the underlying synchronisation algebra and name handling primitives are quite simple and straightforward generalisation of dyadic ones.This is witnessed by the operational semantics rules of our calculus, that in the simpler version (i.e., without message passing) resemble the SOS rules of CCS, while in the full one they resemble the SOS rules of pi-calculus (early variant).As a main result, we show how the new calculus can be used to encode Cardelli and Gordon's Mobile Ambients [5] in a natural way.We prove a tight correspondence at the level of reduction semantics and we provide a bisimilarity semantics for Mobile Ambients as a side result.