Using coloured Petri nets to evaluate the impact of the QoS of failure detectors in the performance of a consensus protocol

It has been proved that it is not possible to solve the consensus problem in an asynchronous distributed system subject to failures. The abstraction of unreliable failure detectors has been presented as a way to extend the pure asynchronous model in order to circumvent this impossibility result. In this paper, we present a hierarchical timed coloured Petri net model of a distributed consensus algorithm for an asynchronous distributed system augmented by an unreliable failure detector. By simulating this model, we evaluate the impact of the quality of service of failure detectors on the performance of the consensus protocol.