Estimating Capacity For Sharing in a Privately Owned Workstation Environment

The author analyzes workstation patterns in order to understand opportunities for exploiting idle capacity. This study is based on traces of users workstation activity in a university environment. It identifies two areas where enhancements can be made. One area is the ability of a manager of the shared capacity of a workstation cluster to schedule jobs with deadline constraints. This opportunity is the result of the ability to make good predictions of the time-varying amount of capacity that is available for sharing. A prediction strategy is developed that is shown to have only a small amount of error. For the second area of enhancement, it is shown that it is feasible to allocate partitions of workstations for specific periods. This aids those users who on occasion need exclusive access to several machines. The author examines the profile of periods during which exclusive access to partitions can be given, the rate that owners preempt users of partitions, and the distribution of interpreemption intervals. >