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 3 Sept 2001 F HARRIS CHEP, Beijing

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 Sept 2001 F HARRIS CHEP, Beijing

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 3 Sept 2001 F HARRIS CHEP, Beijing

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 3 Sept 2001 F HARRIS CHEP, Beijing

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

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

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 3 Sept 2001 F HARRIS CHEP, Beijing

Security M9(October 2001...) M21(October2002….) 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 3 Sept 2001 F HARRIS CHEP, Beijing

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 3 Sept 2001 F HARRIS CHEP, Beijing

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) 3 Sept 2001 F HARRIS CHEP, Beijing

Job Monitoring and data quality checking 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 3 Sept 2001 F HARRIS CHEP, Beijing

Bookkeeping database M9 M21 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 3 Sept 2001 F HARRIS CHEP, Beijing

Data copying and mass storage handling 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) 3 Sept 2001 F HARRIS CHEP, Beijing

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

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

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

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

Conclusions http://lhcb-comp.web.cern.ch/lhcb-comp/ 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/ 3 Sept 2001 F HARRIS CHEP, Beijing