An adaptive scheduling algorithm for fault-tolerant real-time systems

Particularly concerned with the deadline mechanism, proposed as a means to design and implement fault-tolerant real-time systems. The computing system considered uses a single-processor machine to run multiple software processes; each of them executes a task in response to periodic requests. Based on redundancy the deadline mechanism assumes that every task is composed of primary and alternate algorithms. In such a context, the scheduling problem that arises amounts to ensuring timely completion of all the requests, either by primaries or alternates but preferably by primaries whenever possible. The authors present a heuristic scheduling strategy, which is optimal and runs in linear time