ATLAS Computing: Experience from first data processing and analysis Workshop TYL’10

Outline Data collected by ATLAS in ATLAS Data processing model Processing of ATLAS data Analysis of ATLAS data Report about collaboration

Collected data 20 Nov – 23 Dec : first physics run at √s = 900 GeV (few hours √s = 2.36 TeV)  ATLAS recorded ~ 12 μ b -1, 0.5M events 16 Dec- 28 Feb : Winter technical stop Since 30 March : LHC is running at √s = 7 TeV 1 st W 1 st Z

ATLAS Computing Model Three sources of data: – RAW + First processing from detector (Tier0) – Simulated data (Tier2) – Data Reprocessing + simulation reprocessing (Tier1) CERN LYON TOKYOFrench T2s MB/s per day Total data throughput through the Grid: 1 st January to 25 th May 2010 MC reprocessing 2009 data reprocessing JanFeb March April May Start of 7 TeV data-taking 6 GB/s Data and MC reprocessing ~2 GB/s (design)

Hardware ressources in 2010 for ATLAS Lyon (Tier1): CPU : Hep-spec06 ; Disk : 2.8 PB Tape : 1.6 PB Tokyo Tier2: CPU : Hep-spec06 ; Disk : 1.0 PB FR Tier2s (Irfu,LAL,LAPP,LPC,LPNHE): CPU : Hep-spec06 ; Disk : 1.4 PB

Data reprocessing and distribution RAW data collected untill April 2010 processed in 3 days (~60 TB). Can still be faster Data distribution to be done as data are produced → >1.5 Gb/s for site hosting 100% of data (Tokyo, Paris)

Data distribution Lyon->Tokyo Data export rate from Lyon to Tokyo is similar or faster than from Asia/America Good results from close collaboration Tokyo/France Data are available in Tokyo/FR Tiers2 only few hours after data production Lyon BNL (USA-Long Island) Triumf (Canada-Vancouver) ASGC (Taiwan) Tokyo New York SINET GEANT RENATER Lyon 10 Gb/s RTT=300 ms

First analysis stress test STEP09 (June09) Coordinated measurement of processing rate before data taking (2009) Tokyo and most FR sites in the top 10 – Benefit from close discussions between site admins (mails or visits or monthly phone meeting)

Hosting data for physics group Efficient/reliable sites labeled during STEP09 → Can take responsibility to host reduced data (usually Ntuples of selected events) for major physic/performance groups – Opportunity to get some data of interest for local teams – Number of groups scales with size (CPU/storage) of sites Groups in Tokyo : 6 Groups in french sites : 8 Usually complementary

Data analysis In April and May: >900 users, 6.1 million successful jobs (+30% more failed) Reality is 2-3x larger than our average pre-data experiences, though previous tests were essential preparation. Real user analysis activity started -> Optimisation of analysis tools (Benefit from contact with main developper (japanese)) STEP’09 Real data x2-3 increase

Condition Database access for analysis over WAN T1 Oracle Tokyo Direct access RTT (300 ms) Typical analysis job : ~1 evt/sec Typical analysis job : ~1 evt/sec ~10 evt/sec Fr site Caching at T1 & T2 ~10 evt/sec

Members French groupJapanese group E. Lançon*CEA-IrfuT. Mashimo*ICEPP G. RahalIN2P3-CCI. UedaICEPP C. BiscaratIN2P3-CCH. MatsunagaICEPP D. BoutignyIN2P3-CCN. MatsuiICEPP F. HernandezIN2P3-CCJ. TanakaICEPP J. SchwindlingCEA-IrfuT. KawamotoICEPP S. JézéquelIN2P3- LAPP ( * leader)

Members (Roles) ATLAS central operation and production Tier 1 Tier2s Cover all different activities in ATLAS Computing Daily interactions with I. Ueda to Ensure that Tokyo has the same quality of service as french sites Share cloud survey

Common meetings Tokyo (mainly I. Ueda) participates actively to LCG- France meetings: Annual meeting (global review) Monthly meetings (technical meetings) Visits from ATLAS-France to Tokyo Participation to the ATLAS Asia-Pacific Computing workshop in Tokyo (December 09)

Perspective 2010 Continue close collaboration between France and Japan – Exchange informations between sites – Common requests during ATLAS meetings Improve the attractiveness of sites for Grid analysis – Physics groups – Indivual users Adapt to increase by factor 1000 of integrated luminosity (scalability issues)