Towards The Dynamic Adaptability of SOA: AOP and Process Algebra Approach

Service Oriented Architectures (SOA) aim to give methodological and technical answers to achieve interoperabilty and loose coupling between heterogeneous Information Systems (IS). Currently, Web Services are the fitted technical solution to implement such architectures. However, both Web Services providers and clients are faced to some important difficulties to dynamically change their behaviours. From one side, Web Services providers have no mean to dynamically adapt an existing Web Service to business requirements changes. From the other side, Web Services clients have no way to dynamically adapt themselves to the service changing in order to avoid execution failures. In this paper, we show how we achieve a dynamic adaptable SOA by introducing the Aspect Oriented Programming (AOP) paradigm and Process Algebra (PA). We propose a Process Algebra formalism to specify a change-prone BPEL process (base service and aspect services) and demonstrate how to generate a client which dynamically adapt its behaviour to the service changes. We illustrate our approach through a concrete case study and present the Aspect Service Weaver (ASW) tool which implements our concepts.ou