Estimating job runtime for CMS analysis jobs

The basic premise of pilot systems is to create an overlay scheduling system on top of leased resources. And by definition, leases have a limited lifetime, so any job that is scheduled on such resources must finish before the lease is over, or it will be killed and all the computation wasted. In order to effectively schedule jobs to resources, the pilot system thus requires the expected runtime of the users jobs. Past studies have shown that relying on user provided estimates is not a valid strategy, so the system should try to make an estimate by itself. This paper provides a study of the historical data obtained from the CMS Analysis Operations submission system. Clear patterns are observed, suggesting that making prediction of an expected job lifetime range is achievable with high confidence level in this environment.