In many Grid Computing scenarios, when computationally demanding jobs run onto Grid resources, users typically expect to have some assurances about when their job will run. Unfortunately, computational resources are typically controlled by batch queue systems, which don't offer any guarantees (or any other information) about run-times. The exception is when advance reservation is used. However, advance reservation adversely affects resource utilisation, and therefore the resource owner's income, and so is undesirable. Further, while being sufficient for some scenarios, advance reservation is a restricted level of service.

We propose an alternative approach which aims to explore the space between the two aforementioned extreme levels of service, namely, 'run this job whenever it gets to the head of the queue', or 'run this job at this precise time'. The main idea is to provide different levels of service by forging agreements between the different parties (user, resource owner, etc). Such agreements are forged on the basis of different constraints expressed by (and agreed between) the user and/or the resource owner and essentially specify a desired (and agreed) level of service. The use of Service Level Agreements (SLAs) gives rise to a fundamentally new approach for job scheduling on the Grid.

The project, which was funded by the Engineering and Physical Sciences Research Council (EPSRC), started in January 2004 and lasted for four years. Its main findings are summarized in [1] below.

[1] Rizos Sakellariou and Viktor Yarmolenko. Job Scheduling on the Grid: Towards SLA-Based Scheduling. In Lucio Grandinetti (editor), High Performance Computing and Grids in Action, Volume 16 in the Advances in Parallel Computing series, IOS Press, ISBN 978-1-58603-839-7, 2008, pp. 207-222. [pdf]
(Click here for the presentation that preceded this paper)

(click on publications above, for more output related to this project)