A Proactive Adaptation Framework for Composite Web Services

Abstract

Service orientation is a design paradigm consisting of a set of principles governed by a service-oriented architecture (SOA) to support the creation of software systems as a composition of interoperable services. The ability to effectively compose services is not a trivial task due to the dynamic nature of the execution environment of service compositions. In this context, dynamic service selection and composition is a critical requirement and one of the major research challenges for service-based systems. This research investigates the identification, detection and prediction of the need for adaptation as well as ways to autonomously reconfigure the service composition during its execution time in order to improve service reliability and conformance with systems requirements and policies. We propose a framework for proactive adaptation of service compositions that extends current approaches for dynamic service composition by proactively and individually identifying the need for adaptation for each parallel running instance of service composition while avoiding unnecessary changes and distributing load request among different service operations when necessary. Our framework has been tested and validated using different prototypes implemented in both simulated and real environments. The results were favourable with the research objectives and indicates a major gain in the use of the proposed proactive techniques in the execution and adaptation of web service compositions