26 Nov 1999 F Harris LHCb computing workshop

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’

Reconstructed Data

Analysis Group Tags

Analysis Job Results

Monte Carlo Generator

Detector Simulation

Generator Data

Reconstruction

Event Tag Generation

Real Data Production

Sim. Raw Data Raw Data

Reconstruction Data

Event Tags

Event Tags

Analysis Job

Analysis Group Prod.

Analysis Data

Data analysisData Production

Detector/DAQ Analysis Cycle

200 kB 100 kB

70 kB

0.1 kB

10kB

150 kB

0.1 kB

200 Hz

LHCb datasets and processing stages (must update CPU and store reqts.)

26 Nov 1999 F Harris LHCb computing workshop

5

A General view of Analysis (G Corti)(? Patterns of group and user analysis)

MC generator

Raw Data

DST (reconstructed particles , primary vertex)

Reconstruction

Data Acquisition

Detector Simulation

(Group) Analysis ππBo

d

*DKBod

ρπBod

os

od KJ/ψB

MC “truth”Data

“Reconstructed” Physics channels

Physicist Analysis

....,,

,,,,

os

o

K

e

26 Nov 1999 F Harris LHCb computing workshop

6

Status of simulated event production (since june)E van Herwijnen

Sicb version Eventtype Sec/event Mbytes/1000events

Nr. of producedevents

v116/n(correctedsmearing)

41 50 700 10K

v116/n(correctedsmearing)

350000 140 1200 10K

v116/n(correctedsmearing)

350100 190 1250 10K

v116/n(correctedsmearing)

350200 190 1200 10K

v118 41 145 1000 50kv118 350000 275 1750 50kv118 350100 305 1800 50kv118 350200 300 1750 50kv118 (shorthcal)

41 145 1000 10k

v118 (shorthcal)

350200 305 1800 10k

v119 41 150 900 10kv119 350000 260 1500 10kv119 350100 310 1600 10kv119 350200 300 1500 10k

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

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

http://nicewww.cern.ch/~les/monarc/lhc_farm_mock_up/index.htm

26 Nov 1999 F Harris LHCb computing workshop

9

year 2004 2005 2006 2007

total cpu (SI95) 70'000 350'000 520'000 700'000disks (TB) 40 340 540 740

LAN thr-put (GB/sec) 6 31 46 61

tapes (PB) 0.2 1 3 5

tape I/O (GB/sec) 0.2 0.3 0.5 0.5

Farm capacity and evolution

250 Gbps

0.8 Gbps

8 Gbps

…………1400 boxes160 clusters40 sub-farms

12 Gbps*

480 Gbps*

3 Gbps*

1.5 Gbps

100 drives

12 Gbps

5400 disks

340 arrays

……...

LAN-SAN routers

LAN-WAN routers

CERN

CMS Offline Farmat CERN circa 2006

lmr for Monarc study- april 1999

tapes

0.8 Gbps (daq)

0.8 Gbps

5 Gbps

disks

processors

storage network

storage network

farm network

* assumes all disk & tape traffic on storage network double these numbers if all disk & tape traffic through LAN-SAN router

26 Nov 1999 F Harris LHCb computing workshop

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 FilesInitializing DataDefine Activities (jobs)

GUI

Monarc Package

Network Package Data Model Package

Auxiliary toolsGraphics

SIMULATION ENGINE

ParametersPrices

....

Processing Package

Statistics

Regional Center, Farm, AMS, CPU Node, Disk, Tape

Job, Active Jobs, Physics Activities, Init Functions,

LAN, WAN, MessagesData 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)