A Contract Based Approach For Providing Reliability To Services Based Applications. (Une Approche A Base De Contrats Pour La Coordination Fiable Des Services)

This research work addresses reliability of services coordination expressed as nonfunctional properties (e.g., performance, security, atomicity, persistency, etc) that must be ensured and enforced at execution time. Existing systems, models and languages provide ad-hoc solutions that weave the application logic, expressed as services coordination, with non functional properties, leading to applications difficult to evolve and maintain. In contrast, our approach promotes separation of concerns such that reliability can be personalized for a given services coordination where some services can run under persistent connection conditions, others participate in atomic executions, etc. Therefore, we propose a contract model for associating non-functional properties to a services coordination and associated contract evaluation strategies for verifying and enforcing them at run time. A proof of concept is presented, ROSE is a reliable services coordination execution engine able to add exception handling and atomicity properties to a given services coordination. Résumé: Ce travail de recherche aborde la fiabilité de la coordination de services exprimée comme des propriétés non-fonctionnelles (e.g. la performance, la sécurité, l’atomicité, la persistance, etc.) qui doivent être assurées et renforcées en cours dexécution. Les systèmes existants, les modèles et les langages fournissent aujourd’hui des solutions ad hoc qui tissent la logique applicative avec les aspects non-fonctionnels, conduisant à des applications difficiles à faire évoluer et à maintenir. Notre approche favorise la séparation et la personnalisation d’aspects tels que la fiabilité. Nous proposons le modèle de contrats COBA pour décrire l’association des propriétés nonfonctionnelles à une coordination de services, et l’évaluation des contrats grâce aux te l-0 06 65 43 9, v er si on 1 1 Fe b 20 12