Fault-tolerant deployment of dataflow applications using virtual processors

Multi-processors are suited to host a dynamic mix of real-time dataflow applications, but are increasingly subject to faults because of the decreasing feature size. Applications can start and stop as needed if they execute on a private set of Virtual Processors (VPs) that are deployed on the physical processors. This allows online software updates, but makes it impossible to predict the deployment. If a fault renders a processor unusable, the free resources on other processors may be too fragmented to allow its VPs to be re-deployed. We show that mapping an application to more VPs reduces the maximum VP size. This increases the probability of successfully dealing with faults, at the cost of an increase of the total size. Such a mapping can either be run from the start, or we can split the VPs only when a fault occurs. Experiments confirm the feasibility of our approach, and show a trade-off between improved fault-tolerance and resource usage for both strategies.