Comparison of Strategies for Serving Two Streams of Jobs

Highly varying job demands generally consist of many short jobs mixed with several long jobs. In this paper, we consider a simple scenario where two job streams with different level of demands must be processed by the same server. We study the performance of several round-robin variants and FCFSP in such a scenario. The simulation results show that on the one hand, by employing immediate preemption to favor newly arrived jobs, round-robin can effectively reduce the mean response time for the short-job stream, while only slightly increasing the response time for the longjob stream. On the other hand, by assuming the availability of job stream information and always favoring the short-job stream, FCFSP may improve performance. However, to further improve performance, other information if available (e.g., the characteristics of each individual stream) should be considered.