The influence of the structure and sizes of jobs on the performance of co-allocation

Over the last decade, much research in the area of scheduling has concentrated on single cluster systems. Less attention has been paid to multicluster systems, although they are gaining more and more importance in practice. We propose a model for scheduling rigid jobs consisting of multiple components in multicluster systems by pure space sharing, based on the Distributed ASCI Supercomputer. Using simulations, we asses the influence of the structure and sizes of the jobs on the system's performance, measured in terms of the average response time and the maximum utilization. We consider three types of requests, total requests, unordered requests and ordered requests, and compare their effect on the system's performance for two scheduling policies, First Come First Served, and Fit Processors First Served, which allows the scheduler to look further in the queue for jobs that fit. These types of job requests are differentiated by the restrictions they impose on the scheduler and by the form of co-allocation used. The results show that the performance improves with decreasing average job size and when fewer restrictions are imposed on the scheduler.