Main parameters of Russian Tier2 for ATLAS (RuTier-2 model) Russia-CERN JWGC meeting A.Minaenko IHEP (Protvino)

Main Tier-2 tasks Tier-0, Tiers-1: storage of all data types (Raw, ESD, AOD, SIM), event reconstruction, ESD and AOD production, main bulk of calibration The main Tier-2 task is providing facilities for physics analysis using mainly AOD, DPD and user derived data formats It includes also development of reconstruction algorithms using subsets of ESD and Raw All the data used for analysis should be stored on disks and some unique data (user, group DPD) to be stored on tapes also

Main Tier-2 tasks The second important task is a production and storage of MC simulated data The ATLAS computing model implies that simulated data are stored mainly in Tiers-1 but Russian Tier-2 proposes to take the responsibility for the locally produced MC data This implies that the proper modes of access to the data to be granted and the data should be backed-up on the tapes Participation in calibration/alignment activity can be considered if there will be interest from Russian groups

Data taking conditions and data sizes Luminosity – 0.5*10 33 cm -2 sec -1 in 2007 – 2.0*10 33 cm -2 sec -1 in 2008, 2009 – cm -2 sec -1 in 1010 and after Event rate200 events/sec Event numbers10 9 in 2007, 2*10 9 each next year Raw 1.6 MB/event ESD0.5 MB/event AOD0.1 MB/event RawSim2.0 MB/event Reconstruction 15 kSI2k*sec/event Simulation100 kSI2k*sec/event Analysis 0.5 kSI2k*sec/event Luminosity increase in 2010 leads to the event size increase by 50% and reconstruction time by 75%

Evolution of Raw, ESD, AOD sizes in ATLAS

Cost table Disc (CHF/GB) ATape (CHF/GB) CPU (CHF/SI2k) Used lifetimes for the different types of resources: CPU - 3 years Disk- 4 years Tape- 5 years

Resources for simulation Number of events – 20% of real data Contribution of RuTier-2 to total statistics of all MC data – 10% Efficiency of CPU usage – 85% All types of data to be saved on automated tapes All ESD, AOD and 20% of Raw simulated data to be kept on disks permanently It is necessary to take into account needs for re- simulation and availability of several models for a single physics process (not done)

Tables with simulation resources Simulation resources evolution RAW (TB) ESD (TB) AOD (TB) Disc (TB) Tape (TB) CPU (kSI2k) Simulation resources yearly increase Disc (TB) Tape (TB) CPU (kSI2k) Disc (kCHF) Tape (kCHF) CPU (kCHF) Total (kCHF)

Evolution of disk, tape, CPU (kSi2k) simulation resources at RuTier-2

Yearly costs of added disk, tape and CPU simulation resources at RuTier-2

Resources for physics analysis Number of active users – 50 5% of total Raw data and 10% of ESD are permanently kept of disks to be used for algorithm developments and analysis Volume of group DPD data is equal to 50% of AOD data Volume of user data – 1 TB per user for 2008 data only and varies proportionally to events number CPU power needed to analyze 2008 data only by one user – 15 kSI2k Total CPU power is proportional to the number of accumulated events and to the number of users: float CPU = Nuser*(Nev_year[i]/Nev_year[2008])*CPU_user_2008;

Tables with analysis resources Analysis resources evolution RAW (TB) ESD (TB) AOD+DPD (TB) User (TB) Disc (TB) Tape (TB) CPU (kSI2k) Analysis resources yearly increase Disc (TB) Tape (TB) CPU (kSI2k) Disc (kCHF) Tape (kCHF) CPU (kCHF) Total (kCHF)

Evolution of disk, tape, CPU (kSi2k) analysis resources at RuTier-2

Yearly costs of added disk, tape and CPU analysis resources at RuTier-2

Evolution of disk, tape, CPU (kSi2k) total resources at RuTier-2

Yearly costs of added disk, tape and CPU total resources at RuTier-2

Summary RuTier-2 for ATLAS – distributed computing centre shared with other LHC experiments Expected parameters for 2008 are –Disks 975 TB –Tapes 230 TB –CPU 1300 kSI2k Provides facilities for physics analysis of data by active 50 users and MC simulation of 10% of ATLAS simulated data The RuTier-2 model implemented as ROOT macro and has a number of adjustable parameters which had to be tuned for model optimization Important feature – linear rise of practically all resources proportionally to the accumulated statistics Commissioning: resources to be shifted partially to