1 Particle Physics Data Grid (PPDG) project Les Cottrell – SLAC Presented at the NGI workshop, Berkeley, 7/21/99

2 Who are we? Collaboration of 9 sites: 6 DoE Labs: ANL, BNL, FNAL, JLAB, LBNL, SLAC 3 universities: CalTech, U. Wisconsin, SDSC Collaboration of: particle physicists with long history of large collaborations actively promote WANs pioneers in use of networks/collaborations/large data sets computer scientists researching and developing tools & infrastructure

3 Project Objectives Delivery of infrastructure for: –widely distributed analysis of particle physics data –at multi petabyte scales –by thousands of physicists Acceleration of development of: –network & middleware infrastructure aimed at data intensive collaboration science

4 Problem Analysis of Particle Physics data Scale of accelerators & detectors means only a few sites So large collaboration (hundreds to thousands) of physicists from tens to hundreds of sites in tens of countries Create large data sets with hundreds of Terabytes to Petabytes of data over the next decade Some sites already taking data (Jlab, SLAC), some will turn on soon (FNAL), LHC at CERN data taking in 2005, creating simulation data today

5 Goal & relation to NGI Goal (impossible dream): –researchers at universities all over US could query & retrieve hundreds of Terabytes within seconds More than a bandwidth problem –requires creation of intelligent networks & network aware applications Stimulates NGI in 3 areas –DiffServ to allow bulk data to co-exist –Distributed caching –Robustness of distributed services

6 Contributions ANL: Globus grid middleware services SLAC: Objectivity Open File System Caltech: Globally Interconnected Object Databases project FNAL: A data access framework (Sequential Access Method) LBNL: Storage Access Coordination System Wisconsin: Condor distributed resource management system SDSC: Storage Resource Broker (SRM) 2Pbytes robotic storage 6 sites), ~1300 Giga- ops/sec (8 sites), ~ 40TB disk cache (7 sites)

7 Applications (physics data sources) BNL: RHIC data FNAL: RunII/D0 & CDF SLAC: PEP-II/BaBar Caltech, ANL: LHC/Atlas & CMS JLab: Nuclear physics experiments Needs: –bulk transfer of raw data to and reconstructed data between regional data centers - today use tapes, introduces delays of ~2 weeks –code builds at multiple sites –interactive access to analyzed events –many hundreds of Mbps growing to several Gbps in next few years