ReSS: A Resource Selection Service for the Open Science Grid

The Open Science Grid offers access to hundreds of computing and storage resources via standard Grid interfaces. Before the deployment of an automated resource selection system, users had to submit jobs directly to these resources. They would manually select a resource and specify all relevant attributes in the job description prior to submitting the job. The necessity of a human intervention in resource selection and attribute specification hinders automated job management components from accessing OSG resources and it is inconvenient for the users. The Resource Selection Service (ReSS) project addresses these shortcomings. The system integrates condor technology, for the core match making service, with the gLite CEMon component, for gathering and publishing resource information in the Glue Schema format. Each one of these components communicates over secure protocols via web services interfaces. The system is currently used in production on OSG by the DZero Experiment, the Engagement Virtual Organization, and the Dark Energy. It is also the resource selection service for the Fermilab Campus Grid, FermiGrid. ReSS is considered a lightweight solution to push-based workload management. This paper describes the architecture, performance, and typical usage of the system.