1. LHCb computing in Russia
Ivan Korolko (ITEP Moscow)
Russia-CERN JWGC, March 2005

2. Russian participation in LHCb
IHEP (Protvino)
INP (Novosibirsk)
INR (Troitsk)
ITEP (Moscow)
PNPI (St.Petersburg)
RICH mirrors
HCAL
SPD and Preshower
ECAL
Muon System

3. History of LHCb DCs in Russia
K events, 1% contribution
only one centre (ITEP)
M events, 3% contribution
all 4 our centers (IHEP,ITEP,JINR,MSU)
M events, 5% contribution
started to use LCG
2005 …PNPI and INR are joining…

4. 2004 DC Phase 1 Statistics

5. What to “compute” in Russia ?
There are 2 main tasks:
1. Provide facilities for LHC data analysis in all participating Russian institutes.
2. Satisfy collaboration needs

6. LHCb computing model
HLT output:
2000 Hz
For details see LHCb

7. LHCb computing model 1. RAW data → 2x1010 events/year
25 kB/event , 500 TB/year
1 copy stored at CERN and 1 copy in Tier1 centres
2. Reconstruction → 2.4 kSI2k.s/event
2 times per year → 7 months and 2 months
CPU needs : 12MSI2k
storage: 500 TB (rDST)
1 copy stored across CERN and Tier1 centres

8. LHCb computing model 3. Stripping → 2.1x109 events/year
kB/event , 139 TB/year (DST)
4 times per year (1 month)
stored at CERN, Tier1 and some Tier2 centres
4. Analysis → 0.3 kSI2k.s/event
140 physicists , 2 jobs/week , 3x106 events
CPU needs : x(n-1) MSI2k
storage: 200 TB
run at CERN, Tier1 and some Tier2 centres

9. LHCb computing model 5. MC production → 4x109 events/year
~50 kSI2k.s/event (8 MSI2k.years)
400 kB/event
160 TB to store only triggered events (4x108)
produced at Tier2 centres
stored at CERN and Tier1 centres
LHCb trigger differs significantly from ATLAS and CMS

10. Computing in Russia 1. Store stripped data (DST)
2 most recent copies for the current year
1 copy for all previous years
storage: x(n-1) TB
2. Run analysis jobs (~15% of LHCb)
CPU → x(n-1) MSI2k.years
storage: x(n-1) TB

11. Computing in Russia 3. MC production (~10% of LHCb)
CPU → 0.8 MSI2k.years
storage: 3 TB
4. Calibration of detectors, rec. algorithms
CPU → 0.1 MSI2k.years
storage: 30 TB
(hard to estimate now, double analysis needs)

12. Computing in Russia Cluster of Tier2 centres in Russia
partial Tier1 functionality (DST, analysis)
LHCb requirements
CPU → x(n-1) MSI2k.years
storage → x(n-1) TB

13. Contingency
Unlike, for example CMS, LHCb has no contingency beyond a common expt efficiency factor