A comparative evaluation of implicit coscheduling strategies for networks of workstations

Implicit coscheduling strategies enable parallel applications to dynamically share the machines in a network of workstations (NOW) with interactive, CPU and IO-bound sequential jobs. We present a simulation study that compares 12 coscheduling strategies in terms of their impact on the performance of parallel and sequential applications executed simultaneously on a NOW. Our results show that the coscheduling strategy has a strong impact on the performance of the applications (both parallel and sequential) composing the workload, and that no single strategy is able to effectively handle all workloads. In spite of that, our results can be used to identify the strategy that represents the best choice for a given application class, or the best compromise for various workloads. Moreover, we show that in many cases simple strategies outperform more complex ones.