Alea 2: job scheduling simulator

This work describes the Grid and cluster scheduling simulator Alea 2 designed for study, testing and evaluation of various job scheduling techniques. This event-based simulator is able to deal with common problems related to the job scheduling like the heterogeneity of jobs, resources, and the dynamic runtime changes such as the arrivals of new jobs or the resource failures and restarts. The Alea 2 is based on the popular GridSim toolkit [31] and represents a major extension of the Alea simulator, developed in 2007 [16]. The extension covers both improved design, extended functionality as well as the improved scalability and the higher simulation speed. Finally, new visualization interface was introduced into the simulator. The main part of the simulator is a complex scheduler which incorporates several common scheduling algorithms working either on the queue or the schedule (plan) based principle. Additional data structures are used to maintain information about the resource status, the objective functions and for collection and visualization of the simulation results. Many typical objectives such as the machine usage, the average slowdown or the average response time are included. The paper concludes with an example of the Alea 2 execution using a real-life workload, discussing also the scalability of the simulator.