Alea – Grid Scheduling Simulation Environment

This work concentrates on the design of a system intended for study of advanced scheduling techniques for planning various types of jobs in a Grid environment. The solution is able to deal with common problems of the job scheduling in Grids like heterogeneity of jobs and resources, and dynamic runtime changes such as arrivals of new jobs.

Our new simulator called Alea is based on the GridSim simulation toolkit which we extended to provide a simulation environment that supports simulation of varying Grid scheduling problems. To demonstrate the features of the GridSim environment, we implemented an experimental centralised Grid scheduler which uses advanced scheduling techniques for schedule generation. By now local search based algorithms and some dispatching rules were tested.

The scheduler is capable to handle both static and dynamic situation. In the static case, all jobs are known in advance while the dynamic situation means that jobs appear in the system during simulation. In this case generated schedule is changing through time as some jobs are already finished while the new ones are arriving. Comparison of FCFS, local search and dispatching rules is presented for both cases and we demonstrate that the new local search based algorithm provides the best schedule while keeping the running time acceptable.