Cost estimation of advance reservations over queued jobs: a quantitative study

A grid is a geographically distributed resource sharing environment across multiple organizations. The most typical grid resources are clusters with the high performance/cost ratio. In general, these clusters are shared as non-dedicated grid resources since local users may run their jobs simultaneously. Local jobs are usually queued and processed in a batch mode with uncertain waiting time while grid jobs always require advance reservations with guaranteed resource allocation. In this paper, we provide quantitative analysis on the impact of advance reservations over queued jobs, in terms of job waiting time and resource utilization, respectively. It is observed that advance reservations will lead to longer job waiting time and lower resource utilization. That is to say, advance reservations should cost more than queued jobs. In this work, based on quantitative experimental results, an empirical formula for cost estimation of advance reservations over queued jobs is presented. It is suggested that compared with queued jobs, advance reservations should be doubly charged to compensate resource utilization loss. If the notice time of an advance reservation is short below a threshold, additional cost should be applied further since queue waiting time is increased.