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

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

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

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

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

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

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

F Harris LHCb computing workshop http://nicewww.cern.ch/~les/monarc/lhc_farm_mock_up/index.htm 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

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

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

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

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

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