1. LHC Data Analysis using a worldwide computing grid
OSG Consortium Meeting
Gainesville
23 January 2006

2. WLCG Purpose and Collaboration
Develop, build and maintain a distributed computing environment for the storage and analysis of data from the four LHC experiments
Ensure the computing service
… and common application libraries and tools
Phase I – Development & planning
Phase II – – Deployment & commissioning of the initial services
WLCG Collaboration
~100 computing centres around the world
12 large centres (including FNAL, BNL)
~30 federations of smaller “Tier-2” centres
Memorandum of Understanding
Agreed in October 2005, now being signed
Resources
Commitment made each October for the coming year
5-year forward look

4. LCG Service Hierarchy Tier-0 – the accelerator centre
Data acquisition & initial processing
Long-term data curation
Distribution of data  Tier-1 centres
Canada – Triumf (Vancouver)
France – IN2P3 (Lyon)
Germany – Forschunszentrum Karlsruhe
Italy – CNAF (Bologna)
Netherlands – NIKHEF/SARA (Amsterdam)
Nordic countries – distributed Tier-1
Spain – PIC (Barcelona)
Taiwan – Academia SInica (Taipei)
UK – CLRC (Oxford)
US – FermiLab (Illinois)
– Brookhaven (NY)
Tier-1 – “online” to the data acquisition process  high availability
Managed Mass Storage –  grid-enabled data service
Data-heavy analysis
National, regional support
Tier-2 – ~100 centres in ~40 countries
Simulation
End-user analysis – batch and interactive

5. CPU
Disk
Tape

6. LCG Service Deadlines
full physics
run
first physics
cosmics
2007
2008
2006
Pilot Services – stable service from 1 June 06
LHC Service in operation – 1 Oct 06 over following six months ramp up to full operational capacity & performance
LHC service commissioned – 1 Apr 07

7. LCG depends on two major science grid infrastructures
EGEE - Enabling Grids for E-Science
OSG - US Open Science Grid

8. Baseline Services Operated by Centres according to VO and Tier
- Storage Element – SRM -- dCache, DPM, CASTOR, HPSS
- Basic transfer tools – Gridftp, srmCopy.
- Reliable file transfer service – within the VO – all Tier-1s must make data available to all other Tier-1s and to all Tier-2s
- Catalogue services – LFC, Globus RLS
- Catalogue and data management tools – lcg-utils
- Compute element – Globus/Condor-G based CE  Condor-C based CE
- Workload management – -- EGEE Resource Broker, and other solutions -- Operated as services at specific sites -- compatibility with the standard CE is required
- VO agents – prototyping phase – workshop this week in Amsterdam
- VOMS.
- Database services
- POSIX-I/O
- Application software installation
- Job monitoring tools
- Reliable messaging service
- Information system

9. Optical Private Network
Wide Area Network T2 T2 T2 T2
T2s and T1s are inter-connected by the general purpose research networks T2 T2 T2
GridKa T2
IN2P3
10 Gbit links
Optical Private Network
TRIUMF
Any Tier-2 may
access data at
any Tier-1 T2
Brookhaven
ASCC
Nordic T2
Fermilab
RAL
CNAF
PIC T2 T2
SARA T2
LCG T2

10. Sustained Data Distribution Rates CERN  Tier-1s
Centre
ALICE
ATLAS
CMS
LHCb
Rate into T1 MB/sec (pp run)
ASGC, Taipei X
100
CNAF, Italy
200
PIC, Spain
IN2P3, Lyon
GridKA, Germany
RAL, UK
150
BNL, USA
FNAL, USA
TRIUMF, Canada 50
NIKHEF/SARA, NL
Nordic Data Grid Facility
Totals
1,600

11. Service Challenges Purpose
Understand what it takes to operate a real grid service – run for days/weeks at a time (not just limited to experiment Data Challenges)
Trigger and verify Tier1 & large Tier-2 planning and deployment – - tested with realistic usage patterns
Get the essential grid services ramped up to target levels of reliability, availability, scalability, end-to-end performance
Four progressive steps from October 2004 thru September 2006
End SC1 – data transfer to subset of Tier-1s
Spring 2005 – SC2 – include mass storage, all Tier-1s, some Tier-2s
2nd half 2005 – SC3 – Tier-1s, >20 Tier-2s –first set of baseline services
Jun-Sep 2006 – SC4 – pilot service
 Autumn 2006 – LHC service in continuous operation – ready for data taking in 2007

12. Service Challenge 3 Throughput Tests

13. Tier-3s and Opportunistic Resource Usage
Tier-3s - Physics Departments, private systems
Private analysis, simulation
Need easy access to all VO Tier-1s, Tier-2s on EGEE and OSG – job submission, data retrieval
Simulation – opportunistic resource usage on the grid
By carefully limiting the requirements needed from the environment -- LHCb has been very successful on the EGEE grid
Standard job submission, storage interfaces essential

14. Conclusions NOT an option to get things going later
LCG depends on two major science grid infrastructures – EGEE and OSG  inter-operability and standards very important
Job management, storage interfaces, data transfer
Tier-1 and Tier-2 centres –
For components where compatibility is essential baseline services are defined which can be deployed on OSG and EGEE
The Service Challenge programme this year must show that experiments can operate across the different grid infrastructures
Stable, reliable services
By the end of September the underlying grid services must be in continuous, stable operation
First data will arrive next year
We must have an integrated and reliable service well ahead of the first beams
NOT an option to get things going later