Reflective Fault-Tolerant Systems: From Experience to Challenges

This paper presents research work performed on the development and the verification of dependable reflective systems based on MetaObject Protocols (MOPs). We describe our experience, we draw the lessons learnt from both a design and a validation viewpoint, and we discuss some possible future trends on this topic. The main originality of this work relies on the combination of both design and validation issues for the development of reflective systems, which has lead to the definition of a reflective framework for the next generation of fault-tolerant systems. This framework includes: (i) the specification of a MetaObject Protocol suited for the implementation of fault-tolerant systems, and (ii) the definition of a general test strategy to guide its verification. The proposed approach is generic and solves many issues related to the use and evolution of system platforms with dependability requirements. Two different instances of the specified MOP have been implemented in order to study the impact of different MOP implementations in the development of a reflective fault-tolerant system. Our test strategy is then illustrated on one of them. The results obtained from this work justify the interest of the proposed framework. MOP-based Fault-Tolerant Systems: From Experience to Challenges Page 1