Preemption and priority calculation in production job data

In order to offer on-demand computing services as well as improve overall job throughput, the San Diego Supercomputer Center has implemented preemption on its production supercomputers. Preemption allows time critical applications to run as needed and also allows more jobs to be processed through the queue since the jobs can backfill in several smaller discrete blocks of time rather than in one contiguous block. With our local home grown scheduler, Catalina[4], we implemented preemp-tion to enable these new usage scenarios. We explore the impact of the job expansion factor and utilization when preemption and job priority are taken into account on both long-running and large-scale jobs. We simulated real production log using a simulator to investigate preemption impact to scheduling metrics. 1