Contact Person Name Rodney Walker Address High Energy Physics Group Imperial College London The Blackett Laboratory Prince Consort Road, LONDON SW7 2BW Phone 02075947810 Fax +44 (0)207 823 8830 Email rodney.walker@ic.ac.uk Title MC_RunJob: a High Energy Physics Workflow Planner for Grid Production Processing Author 1 Iain Bertram Lancaster University Author2 Dave Evans Lancaster University Author3 Gregory Graham Fermi National Accelerator Laboratory Author4 Philip Lewis Imperial College London Author5 Rodney Walker Imperial College London Author is PC Member No Main Fields 4. Science Application Other Main Fields [None Given] Abstract MC_RunJob is a powerful grid workflow manager used to manage the generation of large numbers of production processing jobs in High Energy Physics. In use at both the DZero and CMS experiments, MC_RunJob has been used to manage large Monte Carlo production processing since 1999 and is being extended to uses in regular production processing for analysis and reconstruction. As described at CHEP 2001, MC_RunJob converts core metadata into jobs submittable in a variety of environments. The powerful core metadata description language includes methods for converting the metadata into persistent forms, job descriptions, mulit-step workflows, and data provenance information. The language features allow for structure in the metadata by including full expressions, namespaces, functional dependencies, site specific parameters in a grid environment, and ontological definitions. It also has simple control structures for parallelization of large jobs. MC_RunJob features a modular design which allows for expansion to new job description languages or new core metadata modules without requiring changes to the core class definitions. Remarks [None Given]