1. Development of LHCb Computing Model F Harris
Overview of proposed workplan to produce
‘baseline computing model for LHCb’
26 Nov 1999
F Harris LHCb computing workshop

2. 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
26 Nov 1999
F Harris LHCb computing workshop

3. 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’
26 Nov 1999
F Harris LHCb computing workshop

4. LHCb datasets and processing stages (must update CPU and store reqts.)
200 Hz
200 kB
100 kB
10kB
150 kB
70 kB
0.1 kB
0.1 kB

5. A General view of Analysis (G Corti) (
A General view of Analysis (G Corti) (? Patterns of group and user analysis)
Data Acquisition
Detector Simulation
Raw Data
MC “truth”Data
Reconstruction
MC generator
DST
(reconstructed particles , primary vertex)
Physicist Analysis
(Group) Analysis
“Reconstructed” Physics channels
26 Nov 1999
F Harris LHCb computing workshop

6. Status of simulated event production (since june) E van Herwijnen
26 Nov 1999
F Harris LHCb computing workshop

7. 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
26 Nov 1999
F Harris LHCb computing workshop

8. F Harris LHCb computing workshop
Mock-up of an Offline Computing Facility for an LHC Experiment at CERN (Les Robertson July 99 with ‘old’ experiment estimates)
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
26 Nov 1999
F Harris LHCb computing workshop

9. F Harris LHCb computing workshop
26 Nov 1999
F Harris LHCb computing workshop

10. CMS Offline Farm at CERN circa 2006 processors tapes ……... disks
storage network
12 Gbps
processors
…………
1400 boxes
160 clusters
40 sub-farms
tapes
1.5 Gbps
0.8 Gbps
8 Gbps
3 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

11. 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
>> BASELINE COMPUTING MODEL together with cost, performance,risk analysis
26 Nov 1999
F Harris LHCb computing workshop

12. The Structure of the Simulation Program (I Legrand)
User Directory
Config Files
Initializing Data
Define Activities (jobs)
GUI
Monarc Package
Network Package
Data Model Package
Auxiliary tools
Graphics
SIMULATION ENGINE
Parameters
Prices
....
Processing Package
Statistics
Regional Center, Farm, AMS, CPU Node, Disk, Tape
Job, Active Jobs, Physics Activities, Init Functions,
LAN, WAN, Messages
Data Container, Database
Database Index
Dynamically Loadable Modules
26 Nov 1999
F Harris LHCb computing workshop

13. 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)
26 Nov 1999
F Harris LHCb computing workshop