Glenn Patrick 31/03/00 CMS(UK)

What is the CMS(UK) Data

Model?Assume that CMS software is available at every UK institute connected by some infrastructure (ie. Grid).

The problem then reduces to:•What datasets are required?•Where are they required?•Why are they required? •Who is going to generate, distribute them?•What are the formats, sizes & access patterns?

Event Tag Data

Physics Objects

Reconstructed Data

Raw Data

DataImport

DataExport

Mass Storage & DiskServers

Database Servers

Tapes

Network from CERN

Networkfrom Tier 2 andsimulation centers

PhysicsSoftware

Development

R&D Systemsand Testbeds

Info serversCode servers

Web ServersTelepresence

Servers

TrainingConsultingHelp Desk

ProductionReconstruction

Raw/Sim-->ESD

Scheduled, predictable

experiment/physics groups

ProductionAnalysis

ESD-->AODAOD-->DPD

Scheduled

Physics groups

Individual Analysis

AOD-->DPDand plots

Chaotic

Physicists Desktops

Tier 2

Local institutes

CERN

Tapes

Support Services

batchphysicsanalysis

batchphysicsanalysis

detector

event summary data

rawdata

eventreconstruction

eventreconstruction

eventsimulation

eventsimulation

analysis objects(extracted by physics topic)

Offline Data andComputation for Physics Analysisevent filter

(selection &reconstruction)

event filter(selection &

reconstruction)

processeddata

CPU for productionMass Storage for RAW, ESD AOD, and TAG

Institute

Selected User AnalysesInstitute

Selected User Analyses

Regional Centre

User analysis

Production Centre

Generate raw dataReconstructionProduction analysis

User analysis

Regional Centre

User analysisRegional Centre

User analysis

Institute

Selected User Analyses

Regional Centre

User analysis

Institute

Selected User Analyses

CPU for analysisMass storage for AOD, TAG

CPU and data servers

AOD,TAGreal : 80TB/yrsim: 120TB/yr

AOD,TAG8-12 TB/yr

LHCb

ProductionCentre

(x1)

RegionalCentre(~x5)

Institute(~x50)

Real Data Simulated Data

Data collectionTriggeringReconstructionFinal State Reconstruction

CERN

WAN Output to each RC:AOD and TAG datasets20TB x 4 times/yr= 80TB/yr

User Analysis

WAN Output to each Institute:AOD and TAG for samples1TB x 10 times/yr= 10TB/yr

RAL , Lyon, ...

Event GenerationGEANT trackingReconstructionFinal State Reconstruction

WAN Output to each RC:AOD, Generator and TAG datasets30TB x 4 times/yr= 120TB/yr

User Analysis

Selected User Analysis Selected User Analysis

WAN Output to each institute:AOD and TAG for samples3TB x 10 times/yr= 30TB/yr

LHCb

Dataflow Model

RAW Data

DAQ system

L2/L3 Trigger

Calibration Data

Reconstruction

Event Summary Data (ESD) Reconstruction Tags

Detector

RAW Tags

L3YES, sample L2/L3NO

ESD Reconstruction Tags

Analysis Object Data (AOD) Physics Tags

First PassAnalysis

Physics Analysis

Private Data

Analysis Workstation

Physics results

ESD RAW

Need to answer questions like...

How will a physicist in Bristol/Brunel/IC/RAL:

• Select events for a given physics channel from a year’s worth of data taking?

• Transfer/replicate the selection for further analysis?

• Generate & process a large sample of simulated events?

• Run his/her batch job on existing samples of Monte-Carlo events (eg. at Tier1/Tier2)?

Where do you want the data?

What sort of data do you need - Tag,AOD,ESD,Raw?

How to Go Forward?• Need to identify critical mass of people formed from all of the institutes who will start to study, develop and exploit CMS(UK) facilities now.

• Require expert(ise) in OO databases - specifically Objectivity (BaBar estimate 1 FTE).

• Each institute needs to start to identify its data requirements for simulation/physics/trigger studies.

• Need to understand how best to distribute, replicate, and centralise database & associated resources.

• Need good organisation with regular meetings, etc.