Priority scheduling for networked virtual environments

Abstract

When simulating large virtual environments (VEs), contention for limited resources such as the CPU, rendering pipeline, or network bandwidth frequently degrades the system's performance. Whenever such a competition occurs and not all elements that require the resource can be serviced, an approximation must be made to avoid compromising interactive performance. We propose an enhancement to the round-robin approach called Priority Round Robin scheduling (PRR). This algorithm enforces priorities, while retaining the output sensitivity and starvation-free performance of round-robin scheduling. Priorities are set by a user-defined error metric (such as visual error), which the algorithm attempts to minimize. This permits not only scheduling the entities competing for a resource such as updates competing for the network, but also filling the gap between filtering and scheduling techniques. We evaluate our algorithm in a client-server system.