Reliable Dynamic Reconfigurations in a Reflective Component Model

Software engineering must cope with a more and more increasing need for evolutivity of software systems in order to make their administration easier. However, evolution and especially dynamic evolution in a system must not be done at the expense of its reliability, that is to say its ability to deliver the expected functionalities. Actually runtime modifications in a given system may lead to inconsistent states and so it can have an impact on its reliability. The aim of this paper is to guarantee reliability of dynamic reconfigurations used to make component-based systems evolve at runtime while preserving their availability. We propose a definition of consistency for configurations and reconfigurations in Fractal component architectures with a model based on integrity constraints like for example structural invariants. Reliability of reconfigurations is ensured thanks to a transactional approach which allows us both to deal with error recovery and to manage distributed and concurrent reconfigurations in Fractal applications.