This paper examines the plausibility of using a network of workstations (NOW) for a mixture of parallel and sequential jobs. Through simulations, our study examines issues that arise when combining these two workloads on a single platform. Starting from a dedicated NOW just for parallel programs, we incrementally relax uniprogramming restrictions until we have a multi-programmed, multi-user NOW for both interactive sequential users and parallel programs. We show that a number of issues associated with the distributed NOW environment (e.g., daemon activity, coscheduling skew) can have a small but noticeable effect on parallel program performance. We also find that efficient migration to idle workstations is necessary to maintain acceptable parallel application performance. Furthermore, we present a methodology for deriving an optimal delay time for recruiting idle machines for use by parallel programs; this recruitment threshold was just 3 minutes for the research cluster we measured. Finally, we quantify the effects of the additional parallel load upon interactive users by keeping track of the potential number of user delays in our simulations. When we limit the maximum number of delays per user, we can still maintain acceptable parallel program performance. In summary, we find that for our workloads a 2:1 rule applies: a NOW cluster of approximately 60 machines can sustain a 32-node parallel workload in addition to the sequential load placed upon it by interactive users.

Article Remote queues: exposing message queues for optimization and atomicity Share on Authors: Eric A. Brewer UC Berkeley UC BerkeleyView Profile , Frederic T. Chong MIT MITView Profile , Lok T. Liu UC Berkeley UC BerkeleyView Profile , Shamik D. Sharma University of Maryland University of MarylandView Profile , John D. Kubiatowicz MIT MITView Profile Authors Info & Claims SPAA '95: Proceedings of the seventh annual ACM symposium on Parallel algorithms and architecturesJuly 1995 Pages 42–53https://doi.org/10.1145/215399.215416Online:20 July 1995Publication History 50citation349DownloadsMetricsTotal Citations50Total Downloads349Last 12 Months10Last 6 weeks2 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access