A Simulation Environment for Job Scheduling on Distributed Systems

In this paper we present a simulation environment for the study of hierarchical job scheduling on distributed systems. The environment provides a multi-level mechanism to simulate various types of jobs. An execution model of jobs is implemented to simulate the behaviour of jobs to obtain an accurate performance prediction. For parallel jobs, two execution models have been implemented: one in which the tasks of the job frequently synchronise and effectively run in lock step and a second in which the tasks only synchronise at beginning and end.The simulator is based on an object approach and on process oriented simulation. Our model supports an unlimited number of workstations, grouped into clusters with their own local resource manager (RM). Work is distributed over these clusters by a global RM. To validate the model, we use two approaches, analysing the main queueing systems and experimenting with real jobs to obtain the actual performance as a reference.