OBSERVING THE IMPACT OF MULTIPLE METRICS AND RUNTIME ADAPTATIONS ON BSP PROCESS RESCHEDULING

摘要

Process rescheduling is an useful mechanism to offer runtime load balancing, mainly in dynamic and heterogeneous environments. In this context, we developed a model called MigBSP which controls the process migration on BSP (Bulk Synchronous Parallel) applications. A BSP application is divided in one or more supersteps, each one containing both computation and communication phases followed by a barrier synchronization. Since the barrier waits for the slowest process, MigBSP's final objective is to adjust the processes location in order to reduce the supersteps' times. Its novel ideas are twofold. The former is represented by the combination of three metrics - Memory, Computation and Communication - in order to measure the Potential of Migration of each BSP process. The second idea consists in offering efficient adaptations that work on the rescheduling frequency. Both ideas turn MigBSP a viable model for getting performance on BSP applications. Meanwhile, it provides a low overhead on application execution when migrations do not take place. This paper presents MigBSP's algorithms, the parallel machine organization, some experimental results and related work.