LHCb Computing
Umberto Marconi
CERN-Russia JWCG, 10/03/2008
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ComputingModel
3
Data flow and distribution
Reconstruction
Stripping
User Analysis
Trigger (2 kHz)
Detector (40 MHz)
RAW
rDST
DST, TAG
Root-tuple
@Tier-1
Simulation
@Tier-2
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LHCb Resource Planning.
MSi2k*year 2008Online Farm 0.36CERN T0 + T1 0.36Tier1s 1.77Tier2s 4.55Total 7.04
11.38 11.3818.30 20.65
1.05 1.534.97 6.84
0.90 0.9020102009 2011
0.902.028.8011.3823.09
20120.902.379.93
11.3824.57
Disk (TB) 2008Online Farm 0CERN T0 + T1 350Tier1s 1025Tier2s 9Total 1385
12783250
20090
2759991
233773 455123
20100
20110
1565374123
5329
20120
1852423223
6107
Tape (TB) 2008Online FarmCERN T0 + T1 631Tier1s 860Tier2sTotal 1491
8534
15105
2012
62958810
20440
11906
20112009 2010
5340 10072
2270 42073070 5864
CPU
Disk
Tape
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Pledged Tier-1s 2Q2008 resources. Tier-1s capacity and requirements for 2Q2008: Pledges are
those from 1st April 2008. https://twiki.cern.ch/twiki/pub/LCG/SC4ExperimentPlans/Tier_1_Capacity_Available_and_Required_2Q2008.xls
Shortage of disk space availability at Tier-1s.
CPU(kSi2k)
Disk/Allocated(TB)
Tape(TB)
1770 1025 500
860
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Pledged Tier-2s.
http://lcg.web.cern.ch/lcg/planning/phase2_resources/P2PRCcaps181207.pdf
Summary of Tier-2s
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Russian Tier-2 Federation
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DC’06
104 concurrent jobs running on LCG
DC06 starts : June ‘06
During DC06 80% of the LHCbwhole production
RAW collected at CERN and distributed to the Tier-1s
emulating real data taking for reconstruction
and stripping at sites
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Distributed Analysis GANGA is the UI used to submit the analysis job
to the Grid. Use of the generic agents also with the analysis
job, downloaded from the DIRAC central queues.
Analysis job vs time
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CCRC’08 Aims
Test the full chain: from DAQ to Tier-0 to Tier-1’s. Test data transfer and data access running concurrently
(current tests have tested individual components). Test DB services at sites: conditions DB and LFC replicas. Tests in May will include the analysis component. Test the LHCb prioritisation approach to balance production
and analysis at the Tier-1 centres. Test sites response to “chaotic activity” going on in parallel
to the scheduled production activity.
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CCRC’08 Planned Tasks RAW data distribution from the pit to the Tier-0 centre.
Use of rfcp into CASTOR from pit to the T1D0 storage class. RAW data distribution from the Tier-0 to the Tier-1 centres.
Use of FTS. Storage class T1D0. Reconstruction of the RAW data at CERN and at the Tier-1s
for the production of rDST data. Use of SRM 2.2. Storage class T1D0
Stripping of data at CERN and at T1 centres. Input data: RAW and rDST on T1D0. Output data: DST on T1D1 Use SRM 2.2.
Distribution of DST data to all other centres Use of FTS - T0D1 (except CERN T1D1)
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CCRC’08 Planned Tasks (II) Preparation of RAW data will occur over the next few month
We need to merge existing MC datasets into ~2GB files February activities:
Maintain the equivalent of 2 weeks data taking. May activities:
Maintain equivalent of 1 month data taking. Run fake analysis activity in parallel to production type
activities using generic agents. Generic agents are the LHCb baseline. It needs to be integral
part of CCRC’08.
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CCRC’08 Status Report LHCb report to LCG MB by Philippe Charpentier
http://indico.cern.ch/conferenceDisplay.py?confId=27472
Resources at Tier-1