Colin Aygalinc - A component model tailored to manage service-oriented pervasive context

Pervasive computing promotes environments where a patchwork of heterogeneous and volatile resources are integrated in daily life. These hardware and software resources cooperate in a transparent way, through applications, in order to provide high value-added services. These services are adapted to each user and its environment, via the notion of context. Pervasive applications are now widely distributed, from distant cloud facilities down to Fog Computing gateway or even in sensors, near the user. Depending on the localization, various forms of context are needed by the applications. In this thesis, we focus on the context module at Fog Level. In order to simplify the design and execution, Fog applications are built on top of a service-oriented platform, freeing the developer of technical complexity and providing a support to handle the dynamism. We propose to extend this approach by providing the context as a set of service descriptions, available at design to the application developer. At runtime, depending on the context sources availability and on application current needs, context services are published or withdrawn inside the platform by the context module. We tailor a specific component model to program this context module. The base unit of our component model is called context entity. It is composed of highly coherent modules, implementing distinctly each service description proposed by the underlying context entity. These modules can simply describe their synchronization logic with context sources thanks to a domain specific language. At runtime, context entity instances can be introspected and recongured. An external autonomic manager uses these properties to match dynamically the context services exposed by the context module to the application needs. We have developed a reference implementation of our work, called CReAM, which can be used in a smart home gateway called iCASA, developed in a partnership with Orange Labs.