Pilot job accounting and auditing in Open Science Grid

The Grid accounting and auditing mechanisms were designed under the assumption that users would submit their jobs directly to the Grid gatekeepers. However, many groups are starting to use pilot-based systems, where users submit jobs to a centralized queue and are successively transferred to the Grid resources by the pilot infrastructure. While this approach greatly improves the user experience, it does disrupt the established accounting and auditing procedures. Open Science Grid deploys gLExec on the worker nodes to keep the pilot-related accounting and auditing information and centralizes the accounting collection with GRATIA.