Using discrete controller synthesis for fault-tolerant distributed systems
INRIA Rhône-Alpes
655 avenue de l'Europe, Montbonnot, 38334 ST Ismier, FRANCE

In order to automatically obtain fault-tolerant real-time systems, we investigate a new solution based on the application of discrete controller synthesis. The real-time systems we consider consist of a set of tasks, and a set of distributed, heterogeneous processors. The latter are fail-silent, and an environment model can detail actual fault patterns. We apply controller synthesis, with objectives w.r.t.\ consistent execution, functionality fulfillment, and some optimizations. We build a task manager that ensures fault-tolerance by migrating the tasks automatically, upon occurrence of a failure, according to the policy specified by the objectives. The advantage is that, once the system is modeled, it becomes possible to study several fault-tolerance policies and to optimize the resulting system according to several criteria. We outline an implementation of our method, using Sigali and Mode Automata.

Keywords: Real-time systems, distributed systems, fault-tolerance, synchronous approach, discrete controller synthesis.

Slides (.pdf)