Integration of Dependability Features in a Synchronous Application

International audienceWe present here an overview of a new approach with associated tools, to implement dependability strategies for applications that follow the reactive synchronous approach. Starting from the description of an application as a graph of interconnected components, we model dependability policies as transformations of this graph. The transformed graph describes a new version of the application that integrates dependability features such as multiple copies of some components, voters that compare the outputs from copies of a component, or behavior checkers that compare the behavior of a component to an expected behavior. The graph transformations rely explicitly on the assumption that the components obey a synchronous execution model. The design of the dependability policies is not addressed. Our goal is only to provide dependability experts with a language for describing such policies and for integrating them into an application. The integration is done off-line and generates a new application with a structure that won't change at runtime. However, runtime changes in the structure of an application are possible and are discussed at the end of this article