Summary of Computing Section of Technical Proposal

1. Summary of Computing Section of Technical Proposal Data Flow Model Computing Requirements Computing Infrastructure Software Strategy Project Organisation and Management Manpower estimates and costs Computing section of LHC-B TP

2. Status of Documents • Draft of Computing Section is available - 5 pages • Based on four Computing Notes containing more details • LHC-B Computing Tasks Requirements • LHC-B Computing Model • LHC- B Software Strategy • LHC-B Project Plan for Computing • Drafts of notes available on Web - still being revised Computing section of LHC-B TP

3. Computing section of LHC-B TP

4. Data Flow Model • Algorithms used for Level 2/3 triggers similar to those employed in full reconstruction. Issues are : • speed, reliability • calibration and alignment in real-time • output of L2 and L3 used by full reconstruction • Size of data store and access speeds 2-3 orders of magnitude higher than current experiments and similar to other LHC experiments • Raw data written to storage at 20 MB/s. • Similar amount of reconstruction information (14 MB/s) • In total capability of storing > 0.4 PB of data/year at 40 MB/s • Transparent access to data store by nearly all tasks Computing section of LHC-B TP

5. Computing Requirements • Estimates of CPU requirements, input/output data volumes based on… • simulation - program exists so good estimates • Assumptions on evolution of algorithms • optimisation (e.g. shower parameterisation) • increasing complexity (more detail) • new frameworks like GEANT4 (30% improvement) • reconstruction - partial information on pattern recognition • Extrapolations from existing experiments (need input from HERA-B) • analysisalgorithms - less well known but needs are smaller • Some numbers are ‘targets’ as opposed to ‘benchmarks’ • for example, goals for L2/L3 are 10/200 msec (on 1000 Mips CPU) Computing section of LHC-B TP

6. Dedicated Installed Processing Power Computing section of LHC-B TP

7. Data Storage Requirements Computing section of LHC-B TP

8. Computing Infrastructure • Issues are • Strategy for evolution of computing model • Timescales for investment in computing resources • Scalability of cpu farms needed for cpu intensive processing • Handling of Petabytes of data stored in a central database • Equal access to data for all collaboration institutes Computing section of LHC-B TP

9. Evolution of Computing Infrastructure • Steady investment in desktop systems • Preparation Phase (1998 - 2000) • 1998 - need is 1000 Mips and 2 TB of data • Use public facilities both inside and outside CERN • Increase of 50%/year in requirements for simulation and analysis • Impact of test-beam? • Implementation Phase (2001 - 2003) • significant increase in our needs (TDRs, full MC, testbeam) • invest in private (SHIFT-like) facilities (end 2000/beginning of 2001) • Commissioning Phase (2004 - 2005) • assembly of full-scale facilities • financing scheme Computing section of LHC-B TP

10. Data Storage Model • All event data stored in a single Object Database • Storage/retrieval managed by a hierarchical mass storage system • Assume 10% of data stored on disk • Study options for access of data from any institute • CERNtric model - all data stored at and accessed from CERN • Regional centres - data distributed between CERN and home labs • Cache (part of) data at each institute • Depends on technology (network), tariffs, logistics, politics Computing section of LHC-B TP

11. Software Strategy • Objectives • quality in software ( trigger, prompt reconstruction….) • performance - trigger latencies, CPU for bulk processing • improve on : • knowledge of PEOPLE involved • the organisation of the development PROCESS • the TECHNOLOGY used • Approach • use appropriate engineering practices • stress importance of architecture - adherence to standards • build high quality components (manpower intensive) • re-use components wherever possible (manpower efficient) • use commercial products when appropriate • participate in common (LHC-wide) projects • plan well - encourage all members of collaboration to participate Computing section of LHC-B TP

12. Software StrategyTechnology • Specialised tools that help building software for all life-cycle activities • project management (MSProject, communication (web), workflow) • verification (inspection, testing) - Purify, Logiscope • configuration management (code and documents of all sorts) • Technology for life-cycle phases • TP states “our intention is to adopt Object Technologies” • OOA (analysis), OOD (design), ODBMS (database), C++/Java (language) integration standards (OMG/CORBA, ActiveX/DCOM, RMI/Javabeans) • large investment by software industry - commercial tools and products widely available (GUIs, distributed systems) • widespread adoption within HEP • GEANT4 - new simulation framework re-engineered using OO • Event Store/Objectivity • Replacement of CERNLIB - OpenGL, IrisExplorer (analysis framework) • Adoption by other experiments (BaBar, STAR, ATLAS/CMS,ALICE..) Computing section of LHC-B TP

13. Benefits of OO • OO evolved out of addressing issues of “programming-in-the-large” • Objects are basis for reusable modules • Communication by message passing helps to define interfaces between modules and external systems • Design essential features of an object that distinguish it from all other objects - defines crisp boundaries (Abstraction) • All internal implementation details are hidden - manage complexity(Encapsulation) • Reuse of well designed/tested modules (objects) gives better quality and leads to high productivity • Partitioning of work into domains is much easier Computing section of LHC-B TP

14. Drawbacks of OO • Field is still developing rapidly and some technologies/products may be superceded • Culture change is necessary and , in general, people hate this • Significant costs associated with training and re-education • OO may not be the last word in software engineering Computing section of LHC-B TP

15. Migration Policy • Steps are as follows : • Build up a suitable programming environment (e.g. C++, UML, Rose) • Develop frameworks for simulation, reconstruction and analysis • impetus will come mid ‘98 with release of GEANT4 and LHC++ toolkits • Embark on intensive training programme • Minimise legacy software - hence set an aggressive schedule • Manpower is an important issue • consolidation of SICB development • need extra (skilled) effort Computing section of LHC-B TP

16. Steering Group • Composition - coordinator plus one rep from each project • Tasks - Coordination, Planning, Resources Computing Facilities Recon- struction Analysis Simulation DAQ Controls OPS Software Eng.Group • Farms • Desktop • Storage • Network • Operating • System • Level 2 FW • Level 3 FW • Recon FW • Calibration • Production • Framewk • Tools • GEANT4 • Framewk • Tools • Production • Event • Builder • Readout • Network • Interfaces • Links • Crates • DAQware • DCS • LHC • Safety • Run • Control • Operations • Consoles • Shift Crew • Enviroment • Methods • Tools • Code • Manag. • Quality • Document. • Training • Licenses • Collab. • Tools Re-usable Components • Data Management : Event Store, Geometry, Database Utilities, ODBMS • Architecture : Frameworks, Component model, Distributed system • Toolkits : GUI, Histograms, Communications • Utilities : data quality monitoring, event display, bookkeeping Computing section of LHC-B TP

17. Links to Sub-detector Groups Application Project (e.g. Reconstruction) RICH Computing Team • Project Leader • Vertex • RICH • Inner Tracker • Outer Tracker • ECAL • HCAL • MUON • Trigger L0 • Trigger L1 • Trigger L2/L3 Computing section of LHC-B TP

18. Life-Cycle Phases • Preparation Phase ( now until end of 2000) Learning • collect requirements and develop functional specifications of subsystems • evaluate hardware technologies • build prototypes • Implementation Phase (start ‘01 until end ‘03) Building • make technology choices • engineer sub-systems • Commissioning Phase (start ‘04 until end ‘04) Testing • install • unit test, integration tests • tests under realistic loads (bulk data, realistic real-time tests) • Operation Phase (start ‘05 until physics goals archived) Running • support • adapt and improve Computing section of LHC-B TP

19. Manpower Estimates Group Comments 98 99 00 01 02 03 04 05 Steering Group 1 1 2 2 2 2 2 2 DAQ 4 6 6 10 10 10 10 8 + 1-2/ subdetector Controls 1 1 1 2 3 3 3 2 Common Project Operations 0 0 0 0 0 1 2 4 Simulation 3 3 3 3 3 3 2 2 + 1-2/sub-detector Reconstruction 2 2 2 3 3 3 3 3 + 1-2/sub-detector Analysis 2 2 2 3 3 4 4 4 interactive applications Re-usable components 2 2 2 7 7 7 4 4 Software Engineering 2 2 2 5 5 5 4 4 Common Project Computing Facilities 2 2 2 5 5 5 8 8 TOTALS 19 21 22 40 41 43 42 41 Computing section of LHC-B TP

20. Cost Estimate Initial Investment Cost 1 Item Units Unit Cost Total Cost 6 CPU ( Mips ) 1x10 3 SFr 3.0 MSFr 2 Disk (TB) 42 12 kSFr 0.5 MSFr Tape (TB) 420 1 kSFr 0.5 MSFr Total 4.0 MSFr Notes : 1. Taken from industry supplied extrapolations to the year 2005 2. Assume 10% of total data taken will reside on disk Annual Investment Costs Item Units Unit Cost Total Cost Desktop CPU 100 100 SFr/month 100 kSFr Software (LHC++,OS) 100 kSFr CPU 500 kSFR Disk 200 kSFr Tape 500 kSFr Total 1400 kSFr Computing section of LHC-B TP

21. Computing section of LHC-B TP