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5 months with LHC data. ATLAS: 1.7 PB raw. CMS: 220 TB of RAW data at 7 TeV 70 TB Cosmics during this period 110 TB Tests and exercises with trigger. . LHCb: 70 TB raw data since June. ALICE: 550 TB. WLCG Usage. Use remains consistently high 1 M jobs/day; 100k CPU-days/day. - PowerPoint PPT Presentation
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5 months with LHC data
LHCb: 70 TB raw data since June
ALICE: 550 TB
ATLAS: 1.7 PB raw
CMS: - 220 TB of RAW data at 7 TeV- 70 TB Cosmics during this
period- 110 TB Tests and exercises with
trigger.
• Large numbers of analysis users
CMS ~500, ATLAS ~1000, LHCb/ALICE ~200
• Use remains consistently high – 1 M jobs/day; 100k
CPU-days/day
WLCG Usage
1 M jobs/day
LHCb
CMS
100k CPU-days/day
ALICE: ~200 users, 5-10% of Grid resources
Job workloadsCMS: 100k jobs per day;Red: analysisLHCb
ATLAS: analysis jobs
ALICE:60 sites, ~20K jobs running in parallel
• Significant use of Tier 2s for analysis – frequently-expressed concern
that too much analysis would be done at CERN is not reflected
CPU – July
• Tier 0 capacity underused in general – But this is
expected to change as luminosity increases
• IT asked to reduce 15M over MTP (2011-15)– Proposal of 12M reduction accepted – this is what was
approved by FC last week• Part (8.25MCHF over 5 years) comes from the LCG
budgets:1. Move to 4-year equipment replacement cycles
• Save 2 MCHF in 2011, very little afterwards
2. Stop CERN contribution to USLHCnet • Save 350 kCHF/year.• NB. No CERN contribution to costs of other Tier 1s
3. Reduce slope of Tier 0 computing resource increase• Save ~ 1 MCHF/year on average• This is the main mechanism we have to reduce costs. Current
assumption was ~30%/year [email protected] 6
Budget Issues at CERN
• Note that the proposals have not been discussed with the experiments, nor with the Committees overseeing LCG (LHCC, RRB/C-RSG, OB, etc...)
• Reducing the Tier-0 Computing resources for LHC experiments does not seem wise now the detectors are ramping up– Not even taking into account the lack of experience with Heavy Ions
• Slowing down the replacement cycles and reducing the slope of computing resources increase– Delays the need for additional computing infrastructure needed for the Tier-0 (e.g.
containers)– Will strictly limit the overall experiment computing growth rate in the Tier-0– Assumes no additional requests from non-LHC experiments– Detailed planning requires further studies
• Extending lifetime of hardware from 3 to 4 years– Does not gain anything if the maintenance is extended– Has negative impact on power budget– Requires additional spares, therefore additional budget– May impact service quality– Implies additional effort to cover for repairs
• USLHCNet– May have secondary effects ... [email protected] 7
Budget implications
• Two points to be addressed:• Scrutiny report of use of resources with experience of
data– Plan to have a report with same details from each
experiment– Discuss with chair of C-RSG at MB on Sep 7
• What should be said about requirements for 2013– According to MoU process should have said something
already– Very difficult to be precise without details of running
conditions, and better analysis of how experience with data correlates with planning (TDR etc).
October RRB
