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Résumé

Dans ce manuscrit, nous proposons de concevoir et de mettre en oeuvre un environnement logiciel pour une "gestion guidée par les modèles" des changements dans les architectures des applications distribuées coopératives. Les aspects adaptabilité des applications, les aspects transformations de graphe et les aspects particuliers des applications distribuées coopératives sont étudiés. Une approche d'adaptation s'appuyant sur une modélisation par les graphes et un style architectural de type Poducteur/Consommateur est présentée pour des applications communicantes collaboratives sensibles au contexte. Une démarche de raffinement est proposée permettant de garantir un certain degré d'adaptabilité en faisant un compromis entre les différents paramètres du contexte. Ces travaux de recherche ont aussi permis de définir un cadre algorithmique générique de reconfiguration architecturale multi-niveaux pour la sélection des architectures de déploiement les plus adaptées à un contexte et aux situations associées. Ce cadre a été appliqué au cas de la communication et de la coopération de groupe. Elle a aussi permis de modéliser le style architectural Producteur/Consommateur pour une communication orientée évènement. Des règles d'adaptation ont été définies. Elles comportent une partie basée sur SWRL pour la description du contexte et des règles d'adaptation, et une partie basée sur les grammaires de graphes pour la transformation des configurations de déploiement

Abstract

In this work, we study dynamic reconfiguration of collaborative communicating applications. Providing generic and scalable solutions for automated self-reconfiguration in group collaboration support systems can be driven by rule-based reconfiguration policies. To achieve this goal, we elaborate a dynamic graph-based modelling approach and we develop structural models that can represent the different interaction dependencies from different configurationrelated point of views: communication flows between the distributed machines, the networked deployment nodes, and the service composition. Our solution is based on graph grammars rewriting. We provide graph transformation to specify rules for changing deployment architecture while being in conformance to an architectural style. In order to handle the complex design of communicating collaborative system architectures and the related adaptation issues, we propose a multi-layer modelling approach. This approach assures generic solutions for automatic context aware adaptation. Our approach is based on the observation that semantic data analysis that can be exploited to manage priorities and more generally to manage communications. This allows us to represent, in a richer way, the semantics of the managed systems.

Mots-Clés / Keywords

Dynamic re-configuration; Graph grammars; Collaboration; Communicating systems; Reconfiguration dynamique; Grammaires de graphes; Système communicants adaptatifs;

Abstract

In this paper, we propose a refinement-based adaptation approach for the architecture of distributed group communication support applications. Unlike most of previous works, our approach reaches implementable, context-aware and dynamically adaptable architectures. To model the context, we manage simultaneously four parameters that influence Qos provided by the application. These parameters are: the available bandwidth, the exchanged data communication priority, the energy level and the available memory for processing. These parameters make it possible to refine the choice between the various architectural configurations when passing from a given abstraction level to the lower level which implements it. Our approach allows the importance degree associated with each parameter to be adapted dynamically. To implement adaptation, we switch between the various configurations of the same level, and we modify the state of the entities of a given configuration when necessary. We adopt the direct and mediated Producer/Consumer architectural styles and graphs for architecture modelling. In order to validate our approach we elaborate a simulation model.

Abstract

Adaptation of deployment is required for maintaining the Quality of Service (QoS) in Service Oriented Architectures (SOA). Dy- namic reconfiguration of SOA is proposed here to to cope with adapta- tion in reaction to or in prediction of QoS degradation. Handling such an issue needs to detect and to identify the deficiency source, and to reconfigure the architecture implementing service composition. System reconfiguration constitutes a complex activity acting on distributed soft- ware entities, and requires to be implemented by correct model-based approaches. We show in this paper how graph grammars can be used to design policy-driven reconfiguration mechanisms of architectures and to rule running applications using reconfiguration laws. We describe how coordinated architectural actions and reconfiguration policies are used to maintain QoS at runtime.