The LHC Computing Grid Project Preparing for LHC Data Analysis NorduGrid Workshop

1. www.cern.ch/lcg The LHC Computing Grid Project Preparing for LHC Data Analysis NorduGrid Workshop Stockholm, 11 November 2002 Les Robertson IT Division, CERN les.robertson@cern.ch

2. Project Goals Goal –Prepare and deploy the LHC computing environmentfor the analysis and management of the data coming from the detectors • applications- tools, frameworks, environment, persistency • computing system global grid service • cluster  automated fabric • collaborating computer centres  grid • CERN-centric analysis  global analysis environment • central role of data challenges This is not another grid technology project – it is a grid deployment project

3. Background • Recommendations of the LHC Computing Review CERN-LHCC-2001-004 – 20 February 2001 • Common solutions and support for applications • Estimates of total requirements and costs • Distributed computing environment using Grid technology • Data recording and reconstruction at CERN • Analysis in Regional Centres and CERN (CERN only a small fraction of the analysis capacity) • Simulation in Regional Centres • Launch Committee – CERN/2379/Rev Council 20 September 200 • organisation • integrating and coordinating work done by experiments, regional centres, grid projects • separating requirements setting (SC2) from implementation (PEB) • reviewed by - technical & scientific – LHC Committee (LHCC) - resources - Computing Resource Review Board (with representatives of all funding agencies)

4. Project Resources Six components • National funding for resources at Regional Centres – funded as resources for LHC experiments • Grid projects – suppliers and maintainers of middleware • funded by EU, NSF, DoE, national and regional investments • CERN personnel and materials • from the base budget – IT and EP • Special contributions by member and observer states of people and materials at CERN during Phase I of the project • Resources from other institutes • signing up for common applications projects • providing infrastructure services for operating the grid, supporting users, maintaining systems software, .. • CERN openlab industrial contributions

5. CERN will provide the data reconstruction & recording service (Tier 0)-- but only a small part of the analysis capacity (Tier 1) • current planning for capacity at principal Regional Centres + CERN • 2002: 650 KSI2000  <1% of capacity required n 2008 • 2005: 6,600 KSI2000  < 10% of 2008 capacity

6. LCG Project Organisation Four work areas – • Applications • Grid deployment • Grid Technology • Fabrics (management & technology of large computing clusters)

7. Applications Area • Base support for the development process, infrastructure, tools, libraries • Frameworks for simulation and analysis • Object persistency and data management • Projects common to several experiments • everything that is not an experiment-specific component is a potential candidate for a common project • long term advantages in use of resources, support, maintenance

8. Applications Work Packages • Software process and infrastructure (SPI) – Alberto Aimar • Persistency framework (POOL) – Dirk Duellmann • Math libraries – Fred James • Core tools and services - Pere Mato • Physics interfaces (Launching) • Detector description (Requirements agreed) • Event generators (Requirements agreed) • Simulation (Requirements stage) • Analysis tools, distributed analysis (next priority)

9. Domain Decomposition Products mentioned are examples; not a comprehensive list slide by Torre Wenaus

10. Simulation • First set of formal requirements for LCG for MC generators (October) and simulation (November) • There is a need for support for both GEANT 4 and FLUKA • GEANT4 • independent collaboration, including HEP institutes, LHC and other experiments, other sciences • significant CERN and LHC-related related resources • MoU being re-discussed now • Proposal to create an HEP User Requirements Committee chaired by an LHC physicist • need to ensure long-term support

11. Grid Deployment • Planning, building, commissioning, operating - - a stable, reliable, manageable Grid for - - Data Challenges • Distributed Production • Distributed Analysis • Integrating services from many Regional Centres around the world • Permanent service – on which Data Challenges are scheduled

12. Grid Deployment Current status • Experiments are doing their event production using distributed resources with a variety of solutions • classic distributed production – send jobs to specific sites, simple bookkeeping • some use of Globus, and some of the HEP Grid tools • vertically integrated solutions (ALIEN)

13. Data Challenges in 2002

14. 6 million events ~20 sites

15. grid tools used at 11 sites Alois.Putzer@cern.ch

16. Grid Deployment The hard problem for distributed computing is data analysis – ESD and AOD • chaotic workload • unpredictable data access patterns this is the problem that the LCG has to solve and this is where Grid technology should really help After two years of grid developmentswe are just at the beginning of grid services

17. Deploying the LHC Grid • A priority now is to move from testbeds to a SERVICE • We need to learn how to OPERATE a Grid ServiceQualityis the Keyto Acceptance of Grids Reliable OPERATIONwill be the factor that limits thepractical size of Grids

18. Centres taking part in LCG-1 around the world  around the clock

19. Centres taking part in LCG-1 Tier 1 Centres • FZK Karlsruhe, CNAF Bologna, Rutherford Appleton Lab (UK), IN2P3 Lyon, University of Tokyo, Fermilab, Brookhaven National Lab Other Centres • GSI, Moscow State University, NIKHEF Amsterdam, Academica Sinica (Taipei), NorduGrid, Caltech, University of Florida, Ohio Supercomputing Centre, Tata Institute (India), Torino, Milano, Legnaro, ……

20. Grid Deployment - The Strategy Get a basic grid service into production so that we know what works, what doesn’t, what the priorities are And evolve from there to the full LHC service • Decide on a common set of middleware to be used for the first LCG grid service – LCG-1 • target - LCG-1 in operation mid-2003 - LCG-1 in full service by end of 2003 • this will be conservative – stability before functionalityand will not satisfy all of the stated requirements • but must be sufficient for the data challenges scheduled in 2004

21. LCG-1 as a service for LHC experiments • Mid-2003 • 5~8 of the larger regional centres • available as one of the services used for simulation campaigns • 2H03 • add more capacity at operational regional centres • add more regional centres • initiate operations centre, user support infrastructure • Early 2004 • principal service for LHC physics data challenges

22. Grid Technology in LCG LCG expects to obtain Grid Technology from projects (well-)funded by national and regional e-science initiatives -- and (later) from industry the LCG project will concentrate ondeploying a global grid service

23. Strategy • Press for complementary middleware developments (world wide) • parallel developments are a problem until the standards emerge • Reduce unnecessary divergence and complexity • Ensure at least one complete and supported solution for LHC • Understand & resolve middleware support issues • As a last resort – develop a plan to meet requirements not taken on by other projects

24. Grid Technology Status • A base set of requirements has been defined (HEPCAL) • 43 use cases • currently funded projects say they will satisfy ~2/3 of these in 2003 • Good experience of experiments working with Grid projects in Europe and the United States •  Practical results from testbeds used for physics simulation campaigns • Everyone builds on the Globus toolkit -- which is undergoing a radical re-design • GLUE initiative – working on integration of the (European) DataGrid project and the (US) Virtual Data Toolkit – VDT • Reliability, Scalability are of major concern • Long term maintenance of tools developed by R&D projects is unclear - quality and commitment • Evolution needed from Research & Development  Engineering

25. Grid Technology – Next Steps • leverage the massive investments being made • proposals being prepared for EU 6th Framework Programme, NSF ITR funding round, national science infrastructure funding • priority: a basic set of reliable, maintainable middleware • hardening / re-engineering of current prototypes • including all the functions that must be common • and at least one example of other essential functions • complementary (or at least coordinated) developments of higher-level functionality by different projects, experiments • prepare for major architectural changes before things mature - do not become too attached to current implementations

26. Proposal for integrated project to harden/re-engineer basic middleware • industrial management – s/w engineering focus • few development centres – funded from different sources • design group - representative of all m/w projects

27. Challenges • Integrating all of the players towards a common goal • Regional Centres, Grid Projects, physics institutes, CERN • Influencing external providers to satisfy LCG requirements – GEANT4, ROOT, .. Grid Projects • Grid technology – • the funding is excellent • but not so obvious that it will provide solid infrastructure suitable for LHC • LCG will be a global grid service – Europe, Asia, America • national ambitions, different agendas make it very hard to navigate – major contrast with WWW! • We are only at the beginning of understanding Grid operation • Grids imply operation and management by the communitya federation not empires

28. The Work Plan • Get a production Grid into operation • Deliver a service to LHC experiments • Understand & fix the real problems