A clairvoyant site allocation policy based on service demands of jobs in a computational grid

In the present paper we evaluate the performance of three different site allocation policies in a 2-level computational grid with heterogeneous sites. We examine the case where service demands of jobs show high variability, and we consider that schedulers are aware of the service times. A simulation model is used to evaluate performance in terms of the average response time and slowdown, under medium and high load. The impact of the various input parameters on performance is also taken into account. Simulation results show that one policy outperforms the other two that are examined, especially at high load. Furthermore, no performance degradation is observed when estimations are used instead of exact knowledge about job service times.