Impact of exploiting load imbalance on coscheduling in workstation clusters

Implicit coscheduling is known to be an effective technique to improve the performance of parallel workloads in time-sharing clusters. However, implicit coscheduling still does not take into consideration the system behavior like load imbalance that severely affects cluster utilization. In this paper, we propose the use of global information to enhance the existing implicit coscheduling schemes. We also introduce a novel coscheduling approach - named PROC (process reordering-based coscheduling) - based on process reordering exploiting global load imbalance information to coordinate communicating processes. The results obtained from an in-depth simulation study show that our approach significantly outperforms previous ones (by up to 38.4%) by reducing the idle time (by up to 86.9%) and spin time (by up to 36.2%) caused by the load imbalance.