1. 3 Sept 2001F HARRIS CHEP, Beijing 1 Moving the LHCb Monte Carlo production system to the GRID D.Galli,U.Marconi,V.Vagnoni INFN Bologna N Brook Bristol E.van Herwijnen,P.Mato CERN A.Khan Edinburgh M.McCubbin,G.D.Patel Liverpool A.Tsaregorodtsev Marseille H.Bulten,S.Klous Nikhef F.Harris Oxford G.N.Patrick,R.A.Sansum RAL

2. 3 Sept 2001F HARRIS CHEP, Beijing 2 Overview of presentation Functionality and distribution of the current system Experience with the use of Globus in tests and production Requirements and planning for the use of DataGrid middleware and security system Planning for interfacing GAUDI software framework to GRID services Conclusions

3. 3 Sept 2001F HARRIS CHEP, Beijing 3 LHCb distributed computing environment (15 countries - 13 European + Brazil,China, 50 institutes ) Tier-0 –CERN Tier-1 –RAL(UK),IN2P3(Lyon),INFN(Bologna),Nikhef,CERN + ? Tier-2 –Liverpool,Edinburgh/Glasgow,Switzerland + ? (maybe grow to ~10) Tier-3 –~50 throughout the collaboration Ongoing negotations for centres (Tier-1/2/3) –Germany,Russia,Poland,Spain,Brazil Current GRID involvement – DataGrid (and national GRID efforts in UK,Italy,+..) –Active in WP8 (HEP Applications) of Datagrid –Will use middleware(WP 1-5) + Testbed(WP6) + Network(WP7) + Security tools

4. 3 Sept 2001F HARRIS CHEP, Beijing 4 Current MC production facilities The max # of CPUs used simultaneously is usually less than the capacity of the farm. Will soon extend to Nikhef, Edinburgh, Bristol

5. 3 Sept 2001F HARRIS CHEP, Beijing 5 Submit jobs remotely via Web Execute on farm Monitor performance of farm via Web Update bookkeeping database (Oracle at CERN) Transfer data to CASTOR mass-store at CERN Data Quality Check on data stored at CERN Distributed MC production, today

6. 3 Sept 2001F HARRIS CHEP, Beijing 6 Distributed MC production in future (using DataGRID middleware) Submit jobs remotely via Web Execute on farm Monitor performance of farm via Web Update bookkeeping database Transfer data to CASTOR (and HPSS, RAL Datastore) Data Quality Check ‘Online’ WP 1 job submission tools WP 4 environment WP 1 job submission tools WP 3 monitoring tools WP 2 data replication WP 5 API for mass storage Online histogram production using GRID pipes WP 2 meta data tools WP1 tools

7. 3 Sept 2001F HARRIS CHEP, Beijing 7 Use of Globus in tests and production Use of Globus simplifies remote production – submit jobs through local Globus commands rather than remote logon Some teething problems in tests(some due to learning curve) –Some limitations to the system (e.g. need large temporary space for running jobs) –Some mismatches between Globus and the PBS batch system (job parameters ignored, submitting >100 jobs give problems) DataGrid testbed organisation will ensure synchronisation of versions at sites + Globus support

8. 3 Sept 2001F HARRIS CHEP, Beijing 8 Security M9(October 2001...) –Authorisation group working towards tool providing single log-on and single role for individual –Individual will get certificate from national CA –Must work out administration for this at start for experiment VO. Probably ~10 users for LHCb M21(October2002….) –Single log-on firmly in place. Moved to structured VO with (group,individual) authorisation. Multiple roles –Maybe up to ~50 users

9. 3 Sept 2001F HARRIS CHEP, Beijing 9 Job Submission M9 –Use command line interface to WP1 JDL. ‘Static’ file specification. –Use environment specification as agreed with WP1,4 (no cloning) M21 –Interface to WP1 Job Options via LHCb application (GANGA). Dynamic ‘file’ environment according to application navigation –May require access to query language tools to metadata –More comprehensive environment specification

10. 3 Sept 2001F HARRIS CHEP, Beijing 10 Job Execution M9 –Will run on farms at CERN, Lyon, RAL for first tests Extend to Nikhef, Bologna, Edinburgh once we get stability –Will use a very simple environment (binaries) –‘Production’ flavour for work M21 –Should be running on many sites (? 20) –Complete LHCb environment for production and development, without AFS (use WP1 ‘sandboxes’) –Should be testing user analysis via GRID, as well as performing production(~50)

11. 3 Sept 2001F HARRIS CHEP, Beijing 11 Job Monitoring and data quality checking M9 –Monitor farms with home- grown tools via Web –Use home-grown data histogramming tools for data monitoring M21 –Integrate WP3 tools for farm performance (status of jobs) –Combine LHCb ideas on state management and data quality checking with DataGrid software

12. 3 Sept 2001F HARRIS CHEP, Beijing 12 Bookkeeping database M9 –Use current CERN- centric Oracle based system M21 –Moved to WP2 metadata handling tools ? ( ? Use of LDAP, Oracle) –This will be distributed database handling using facilities of replica catalogue and replica management –LHCb must interface applications view (metadata) to GRID tools. ?query tools availability

13. 3 Sept 2001F HARRIS CHEP, Beijing 13 Data copying and mass storage handling M9 –WP2 GDMP tool via command line interface to transfer Zebra format files(control from LHCb scripts) –WP5 interface to CASTOR M21 –GDMP will be replaced by smaller tools with API interface. Copy Zebra +Root + ? –Tests of strategy driven copying via replica catalogue and replica management –WP5 interfaces to more mass storage devices. (HPSS+RAL Datastore)

14. 3 Sept 2001F HARRIS CHEP, Beijing 14 Gaudi Architecture Converter Algorithm Event Data Service Persistency Service Data Files Algorithm Transient Event Store Detec. Data Service Persistency Service Data Files Transient Detector Store Message Service JobOptions Service Particle Prop. Service Other Services Histogram Service Persistency Service Data Files Transient Histogram Store Application Manager Converter Event Selector

15. 3 Sept 2001F HARRIS CHEP, Beijing 15 GAUDI services linking to external services Converter Algorithm Event Data Service Persistency Service Algorithm Detec. Data Service Persistency Service Message Service JobOptions Service Particle Prop. Service Other Services Histogram Service Persistency Service Application Manager Converter Event Selector Analysis Program OS Mass Storage Event Database PDG Database DataSet DB Other Monitoring Service Histo Presenter Other Job Service Config. Service Transient Transient Detector Store Transient Histogram Store Transient Event Store

16. 3 Sept 2001F HARRIS CHEP, Beijing 16 Another View Algorithms Gaudi Services API Application external Services API Gaudi Domain Grid Domain

17. 3 Sept 2001F HARRIS CHEP, Beijing 17 GANGA: Gaudi ANd Grid Alliance GAUDI Program GANGA GUI JobOptions Algorithms Collective & Resource Grid Services Histograms Monitoring Results

18. 3 Sept 2001F HARRIS CHEP, Beijing 18 Conclusions LHCb already has distributed MC production using GRID facilities for job submission Will test DataGrid M9 (Testbed1) deliverables in an incremental manner from October 15 using tools from WP1-5 Have commenced defining projects to interface software framework (GAUDI) services (Event Persistency, Event Selection, Job Options) to GRID services Within the WP8 structure we will work closely with the other work packages (middleware,testbed,network) in a cycle of (requirements analysis, design, implementation,testing) http://lhcb-comp.web.cern.ch/lhcb-comp/ http://datagrid-wp8.web.cern.ch/DataGrid-WP8/