LHCb computing model and the planned exploitation of the GRID Eric van Herwijnen, Frank Harris Monday, 17 July 2000

Overview  LHCb computing model and existing resources  EU GRID project participation  GRID unique opportunity to unify CPU resources in the collaborating institutes  Mini project  EU GRID project submitted Paper by F. Harris at:

LHCb computing model  RICH and VertexDectector require detailed optimisation studies  High level triggers and physics studies require large amounts of simulated background and channel data  Simulation largely (2/3) to be done outside CERN (1/3)  GRID to be used with existing FTN based simulation program

Current resources for MC production  CERN: PCSF, 60 queues running WNT  RAL: 30 queues running WNT  Liverpool 300 PC farm running Linux  Short term objective: move away from WNT to Linux and use the GRID

LHCb WP8 application (F. Harris) MAP Farm(300 cpu) at Liverpool to generate 10 7 events over 4 months. MAP Farm(300 cpu) at Liverpool to generate 10 7 events over 4 months. Data volumes transferred between facilities: Data volumes transferred between facilities: Liverpool to RAL3TB (RAW,ESD,AOD,TAG) Liverpool to RAL3TB (RAW,ESD,AOD,TAG) RAL to Lyon/CERN0.3TB (AOD and TAG) RAL to Lyon/CERN0.3TB (AOD and TAG) Lyon to LHCb inst.0.3TB (AOD and TAG) Lyon to LHCb inst.0.3TB (AOD and TAG) RAL to LHCb inst.100GB (ESD for sys. studies) RAL to LHCb inst.100GB (ESD for sys. studies) Physicists run jobs at regional centre or move AOD & TAG data to local institute and run jobs there. Physicists run jobs at regional centre or move AOD & TAG data to local institute and run jobs there. Also, copy ESD for 10% of events for systematic studies. Also, copy ESD for 10% of events for systematic studies. Formal Production scheduled  start 2002 to mid-2002 (EU schedule) Formal Production scheduled  start 2002 to mid-2002 (EU schedule) BUT we are pushing ahead to get experience so we can define project requirements Aim for a ‘production’ run by end 2000 On basis of experience will give input on HEP application needs to the Middleware groups

GRID starting working group  Glenn Patrick  Chris Brew  Frank Harris  Ian McArthur  Nick Brook  Girish Patel  Themis Bowcock  Eric van Herwijnen  others to join from France, Italy, Netherlands etc.

Mini project (1)  Install Globus at CERN, RAL and Liverpool CERN: installation completed on a single Linux node (pcrd25.cern.ch) running Redhat 6.1, not available to public yet RAL: installed but not yet tested MAP: being installed  Members to get access to respective sites  Timescale: 1st week in August

Mini project (2)  Run SICBMC at CERN, RAL and Liverpool Prepare a script using Globus commands to run sicbmc and copy the data back to the host where the job was executed from Other partners to test the script from their sites  Timescale: middle of August

Mini project (3)  Verify data can be shipped back to CERN and written onto tape Use globus commands Some scripting required to use SHIFT and update bookkeeping database  Time scale: end of August  Benchmark sustained datatransfer rates

 Globus: toolkit has a C API (easy to integrate with Gaudi) commands for remotely running scripts (or executables), recovering data from std output, saving consulting metadata through LDAP  The gains: Everyone uses the same executable Everyone uses the same scripts Data is handled in a uniform way  Batch system (LSF, PBS, Condor) to be discussed Integration of the GRID between CERN, RAL and MAP (1)

Integration of the GRID between CERN, RAL and MAP (2)  Explore the use of LDAP for bookkeeping database: API in C would solve current Oracle -> Gaudi interface problem Simplification of DB updating by MC production Everybody is heading in this direction Oracle have an LDAP server product, someone should investigate  Java job submission tools should be modified to create Globus jobs. Timescale: October (to be done in parallel with current NT production)

Integration of the GRID between CERN, RAL and MAP (3)  RAL NT farm to be converted to Linux this autumn  MAP uses Linux  CERN have been asked to install Globus on the Linux batch service (LSF)  A full MC production run using Globus is aimed for in december

Extension to other institutes  Establish a “GRID” architecture: Intel PCs running Linux Redhat 6.1 LSF, PBS or Condor for job scheduling Globus for managing the GRID LDAP for our bookkeeping database java tools for connecting production, bookkeeping & GRID