Workload Evolution on the Cornell Theory Center IBM SP2

The Cornell Theory Center (CTC) put a 512-node IBM SP2 system into production in early 1995, and extended traces of batch jobs began to be collected in June of that year. An analysis of the workload shows that it has not only grown, but that its characteristics have changed over time. In particular, job duration increased with time, indicative of an expanding production workload. In addition, there was increasing use of parallelism. As the load has increased and larger jobs have become more frequent, the batch management software (IBM's LoadLeveler) has had difficulty in scheduling the requested resources. New policies were established to improve the situation. This paper will profile how the workload has changed over time and give anin-depth look at the maturing workload. It will examine how frequently certain resources are requested and analyze user submittal patterns. It will also describe the policies that were implemented to improve the scheduling situation and their effect on the workload