LHCb Computing Model and related activities MONARC etc.

1
LHCb Computing Model and related activities
(MONARC etc.)

• F Harris(Oxford/CERN)

2
LHCb datasets and processing stages
200 Hz
200 kB
100 kB
10kB
70 kB
150 kB
0.1 kB
0.1 kB
3
Data Rates
DAQ
Reconstruction
Reprocessing
Simulation
14 MB/s
20 MB/s
20 MB/s
14 MB/s
35 MB/s
DATA REPOSITORY
Reconstructed
660 MB/s
360 MB/s
4 MB/s
User Analysis
Physics analysis
4
Computing Model - To be studied

• MONARC
• study access patterns
• simulation
• technology watch

5
Current LHCb point of view for a possible
computer model

• Raw data stored at CERN
• All major data reconstructions done at CERN
• Full reconstructed data could be transferred to
  RCs , or data selected by group analysis
• We have open mind about number of RCs and their
  function (to be fully discussed with institutes
  and appropriate national organisations)
• There will be specialised RCs (e.g. for Monte
  Carlo)

6
MONARC - project phases and milestones

• Phase1 (started around October 98)
• Dec 98 Choice of modelling tool
  (DONE Javasim)
• Jan 99 Validation with existing expt
  coming ?
• Mar 99
• First sims of LHC models
  have done some top level
• Start testbed measurements
  ?
• April 99 Choose range of models to be
  simulated at workshop ?
• June 99
• Completion of first simulations
  and analysis of results
• Progress report with workplan
  for Phase 2
• Phase2(start July 99)
• August 99 Completion of coding and
  validation of 2nd round models
• Nov 99 Another cucle of simulation
  completed
• Dec 99 Project completed - deliver
  baseline models
• Phase3 (??) ?? Prototype designs and test
  implementations (?what does LHCb want)

7
Site and Network Architecture - Documents

• http//nicewww.cern.ch/les/monarc/base_config.htm
  l
• Rough Sizing Estimates for a Minimal Regional
  Centre L Robertson
• http//home.cern.ch/barone/monarc/RCArchitecture.
  txt
• Regional Centers for LHC computing
  L Barone
• http//home.fnal.gov/odell/monarc_report.html
• Monarc Report on Existing Computing Architectures
  J Butler(FNAL) et al

8
LHCb views on MONARC

• LHCb will be responsible for developing its own
  Computing Model (we are revisiting this nowdata
  flow model , RC planning...)
• LHCb will welcome information on measurements of
  parameters crucial to evaluation of key
  technologies
• Database times to populate, cluster,replicate...
• Network capacities, costs
• LHCb is beginning by making spreadsheet
  calculations using averages.
• Loads for differerent scenarios calculated by
  multiplying averages
• Duty factors will be included for estimating
  realistic peak loads
• There are some reservations about predictive
  power of detailed simulations (e.g. simulating
  human behaviour..). However we are very impressed
  by developments in the simulation tool. We need
  to understand the key parameters (and the
  tool!), and attempt to bridge the gap spreadsheet
  to tool modelling.
• (? MONARC as forum for RC planning
  discussionsmust ensure expt. Management
  involved)