一种适用于机群系统的任务动态调度方法*

任务调度是机群系统上实现并行计算需要解决的重要问题之一.对于在运行中动态产生任务的并行应用程序,由于很难作出准确的任务分配决策,可能导致各个计算结点的任务负载失衡,最终引起整个系统的性能显著下降.因此,需要通过任务再分配来维持负载平衡.该文提出一种任务分配与再分配方法,它通过尽量延迟任务的执行开始时刻,在任务再分配时避免了进程迁移,使得引入的调度开销很小.分析和实验结果表明,该方法在许多情况下能够有效地提高并行程序的运行性能.

A Dynamic Task Scheduling Method in Cluster of Workstations

Task scheduling is an important issue in the research of parallel computing in cluster of workstations. Because it is difficult to make precise decision of task allocation when running parallel applications that dynamically spawn tasks, load imbalance maybe occur and the performance of whole system will decrease dramatically. So task reallocation is necessary for load balancing. A method for task allocation and reallocation is presented in this paper. By deferring the task's real start-time, it avoids process migration in task reallocation. Therefore, the overhead is greatly decreased. Analysis and experiments show that this method can effectively improve the performance of parallel applications in many cases.