Status of the LHCb MC production system Andrei Tsaregorodtsev, CPPM, Marseille DataGRID France workshop, Marseille, 24 September 2002

Contents  Introduction  Production status  Data management  Job submission  Data production monitoring  Bookkeeping  DataGrid involvement status and plans  Conclusions

Introduction  LHCb – one of the 4 LHC experiments for studies of the CP violation phenomena in the Beauty system;  The experiment is reconsidering the general setup now: The revised TDR due September 2003; Will be based on the large volume MC data; An adequate MC production system is being set up now.

Summer 2002 production = Data Challenge 1  In 48 days we produced 3.3 M events ( 6 TB of data ) We have shown we can produced ~70 K per day We can expect to produce ~ 100 K per day when all centres are operational. Usual job (sim+reco) of 500 events: 390s/evt (I.e. 55 hours of CPU ! More than T class limit in CC) SICBMCsimulation(s/evt)Brunelreconstruction(s/evt)RAWHGeant(KB/evt)OODSTReco.(KB/evt) Min bias BB incl

Centers productivity (summer 2002 run)  Contributions (events produced): CERN (1452 k) Bologna (1009 k) Lyon (595 k) RAL (130 k) Cambridge (37 k) Moscow (27 k) Amsterdam/VU (25 k) Rio (24 k) Oxford (24 k)

Some Data Challenge 1 lessons  Thorough data quality checks on each step: Formal based on log files analysis; Informal based on a small analysis job for the produced data;  Crash trace back;  Flexible workflows should be possible;  Production centre dependancies should be as limited as possible;  Bookkeeping: Maintaining integrity; Managing distributed replicas.

Next Data Challenge 2  MC production = Physics Data Challenge;  Volume: DC2 = 10 x DC1;  Available capacity seems to match requirements: ~1000 CPU world wide during 5 months;  Planning for the DC2: Production software ready by mid Nov 2002; Preproduction: mid Dec 2002 – mid Jan 2003; Production: Feb – May 2003.

Status remote centres (autumn 2002) CenterNo. of CPU’s (1 GHz)Production tools CERN~ 400new Lyon60 +new Liverpool~ 120new Imperial College~ 100new DataGrid~ 20new RAL~ 300old Bologna~ 200old Nikhef~ 20old Bristol~ 20old Edinburgh~ 120old Cambridge~ 15old Oxford~ 10old Moscow~ 40old Rio~ 20old Total~ 1000 (outside CERN)

Data Management

Job workflow  Workflow consists of several steps with various executables running in a certain order

Job configuration  Workflow definition: Executables; Input data types; Output data types;  Job step parameters: Executable algorithm parameters; Statistics; Monitoring mode.

Algorithms configuration

Job submission Storage Local production demon Production center Bookkeeping DB Data Production DB CERN Monitoring service Castor Job scripts Production service Bookkeeping service

Local production demon (at a production center)  Customized for the particular center;  Checks availability of the local resources;  Gets jobs scripts from the Production service;  Installs the necessary software if needed;  Submits jobs;  Updates job status in the Production DB;  Checks the jobs output;  Initiates data transfer to CERN/Castor;  Updates the Bookkeeping database;  Technology: Python; XML-RPC, can easily migrate to SOAP;

Data Production and Job Monitoring PVSS

Bookkeeping  Bookkeeping DB available via a Web service interface: XML-RPC server; ODBC mediated persistant back-end (ORACLE, MySQL)  Flexible schema: Allow easy addition of new data types, parameters; Handles distributed dataset replicas;  Web based user GUI is in the works.

DataGrid status and plans  Installation operational  Long job problem fixed  Long file transfer problem (~ 1 Gb)  New production tools being installed  Test: Run 500 event MC generation Store on SE Recover logs and histograms to CERN Run reconstruction. Output to SE. Recover log files and histos. Write recon output to mass store (Castor) Read Castor data with an analysis job outside Grid

Conclusions  Data Challenge 1 in summer 2002 – the need to upgrade the production tools;  Deployment of the new Data Management tools: Oct-Dec 2002 to support Data Challenge 2 production;  DC2 in Dec 2002 – May 2002;  DataGRID facilities will be used in DC2.