Development of LHCb Computing Model F Harris

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Development of LHCb Computing ModelF Harris

• Overview of proposed workplan to produce
• baseline computing model for LHCb

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WHY are we worrying NOW about this?

• HOFFMAN REVIEW (starting Jan 2000)
• How will the LHC experiments do their computing?
  Answers in late 2000
• The basic logical data flow model, patterns of
  use, resources for tasks
• The preferred distributed resource model
  (CERN,regions,institutes)
• Computing MOUs in 2001
• Countries (UK,Germany, ) are planning now for
  development facilities

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Proposed project organisation to do the work
Tasks and Deliverables(1)

• Logical data flow model (all data-sets and
  processing tasks)
• Data Flow Model Specification
• Resource requirements
• Data volumes,rates,CPU needs by task (these are
  essential parameters for model development) -
  measure current status and predict the future
• URD giving distributions
• Use Cases
• map demands for reconstruction, simulation,
  analysis, calibration and alignment onto the
  model (e.g. physics groups working)
• Document patterns of usage and resulting
  demands on resources - workflow specification

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LHCb datasets and processing stages (must update
CPU and store reqts.)
200 Hz
200 kB
100 kB
10kB
70 kB
150 kB
0.1 kB
0.1 kB
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A General view of Analysis (G Corti)(? Patterns
of group and user analysis)
Data Acquisition
Detector Simulation
Raw Data
MC truthData
Reconstruction
MC generator
DST (reconstructed particles , primary vertex)
Physicist Analysis
(Group) Analysis
Reconstructed Physics channels
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Status of simulated event production (since
june)E van Herwijnen
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Tasks and Deliverables (2)

• Resource distribution
• Produce description of distribution of LHCb
  institutes, regional centres and resources
  (equipment and people), and the connectivity
• Resource Map with network connectivity.
• List of people and equipment
• Special requirements for remote working
• (OS platfoms,s/w distribution,videoconferencing..
  )
• URD on Remote working
• Technology Tracking
• (Follow PASTA. Data Management s/w, GAUDI data
  management.)
• Technology trend figures
• Capabilities of data management s/w

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Mock-up of an Offline Computing Facility for an
LHC Experiment at CERN (Les Robertson July 99
with old experiment estimates)
http//nicewww.cern.ch/les/monarc/lhc_farm_mock_u
p/index.htm

• Purpose
• investigate the feasibility of building LHC
  computing facilities using current cluster
  architectures, conservative assumptions about
  technology evolution
• scale performance
• technology
• power
• footprint
• cost
• reliability
• manageability

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storage network
12 Gbps
processors
1400 boxes 160 clusters 40 sub-farms
tapes
1.5 Gbps
0.8 Gbps
3 Gbps
8 Gbps
12 Gbps
farm network
480 Gbps
0.8 Gbps (daq)
100 drives
LAN-SAN routers
CMS Offline Farm at CERN circa 2006
LAN-WAN routers
250 Gbps
storage network
5 Gbps
0.8 Gbps
5400 disks 340 arrays ...
disks
assumes all disk tape traffic on storage
network double these numbers if all disk tape
traffic through LAN-SAN router
lmr for Monarc study- april 1999
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Tasks and Deliverables(3)

• Candidate Computer Models evaluation
• Map data and tasks to facilities (try different
  scenarios)
• Develop spreadsheet model with key parameters-get
  average answers
• Develop simulation model with distributions
• Evaluate different models (performance,cost,risk.
  .)
• Establish a BASELINE MODEL
• gtgt BASELINE COMPUTING MODEL together with cost,
  performance,risk analysis

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The Structure of the Simulation Program (I
Legrand)

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Proposed composition and organisation of working
group

• Contacts from each country
• Contacts from other LHCb projects (can/will have
  multi-function people..)
• DAQ
• Reconstruction
• Analysis
• MONARC
• IT (PASTA ?)
• Project Plan (constraint - timescales to match
  requests from the review..)
• Monthly meetings? (with videoconferencing)
• 1st meeting week after LHCb week (first try at
  planning execution of tasks)
• Documentation
• all on WWW (need a WEBMASTER)