Hardware and software fault tolerance: definition and evaluation of adaptive architectures in a distributed computing environment

This paper discusses the issue of providing tolerance to both hardware and software fauls by defining several hybrid-faul-tolerant architectures, wich can co-exist and work simultaneously at the top of the supporting environment, and introduces a systematic method for evaluating their dependability efficiency and reponse time. To addredd general- purpose distributed system where multiple unrelated applications may compete for system resourses, our architectural solutions have an important concern with adaptation in the use of redunancy according to system conditions