1. Status: ATLAS Grid Computing
Santiago González de la Hoz
Reunión ATOPE
18 Mayo 2010
S. González

2. Tier1ES Storage Tier-1 ATLAS capacities
Software used to manage disk is dCache
Running version
They use a single instance for all our experiments
ATLAS, CMS, LHCb, MAGIC, PAUS
Total capacity available is around 2.3PB (disk)
Tier-1 ATLAS capacities
2010 disk and tape capacities already covered
Full CPU capacity deployed in June with the new datacenter expansion
S. González

3. Tier1ES
April Reprocessing campaing
Schedule downtime
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4. Tier1ES Real reprocessed data and MC reconstruction tranfer
PIC=> Tier2
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5. ES Cloud
Production Data processing
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6. TIER2ES
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7. ES Cloud
User Analysis (only ANALY_PANDA)
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8. TIER2ES
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9. TIER2ES
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10. TIER2-IFIC
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11. TIER2-IFIC
Recursos CPU 2009
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12. TIER2-IFIC
Recursos CPU 2010
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13. TIER2-IFIC
Servicios y Uso Irregular de la CPU
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14. Tier2-IFIC Planes
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15. ATLAS Tier3? Working definition Goals/constrains
“Non pledged resources”
“Analysis facilities” at your University/Institute/...
Goals/constrains
Emphasis on user analysis
IO intensive. Iterative batch (athena), interactive (root/proof)
Do not increase the overall complexity
Do not require more central-operation effort
Emphasis on simplicity and “low cost”
Do not use physicists to do sysadmin
Solution?
Privilege client-based solutions
Extensive use of caches
Positive side effects?
Learn more on distributed computing for ATLAS computing evolution (long term)
S. González

16. ATLAS Tier3 Activities 6 working groups set up in Jan/Feb Key points
Quickly setup!
Lot of quality work!
Credits to the working-group chairs
Key points
ATLAS-wide collaboration
Established/reinforced links with “external” experts
Converge on an ATLAS Tier3 model
Uniform across the Tier3 sites
Build a Tier3 community
S. González

17. ATLAS Tier3 working groups
DDM-Tier3 link
How to “download” the data...
S. Campana (CERN)
Data access (Lustre/Xrootd)
Main data access via file system or file-system like
S. Gonzalez La Hoz (Valencia) and R. Gardner (Chicago and OSG)
Also creating an inventory and a knowledge base!
Software / Conditions data
Data distribution and caching of “auxiliary” data
A. de Salvo (INFN Roma) and A. da Silva (TRIUMF)
Tier 3 Support
Tools/infrastructure: HammerCloud, DAST, docs...
D. Van der Ster (CERN)
PROOF Working Group
Parallel ntuple scan
Neng Xu (Wisconsin) and W. Ehrenfeld (DESY)
Virtualization
Yushu Wu (LBNL)
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18. Transformative technologies
By their operational requirements non-grid Tier 3 sites will require transformative ideas and solutions
Short term examples
CVMFS (Cern VM web file system)
Minimize effort for ATLAS software releases
Conditions DB
Xrootd/Lustre
Allows for straight forward data access (no SRM)
Wide area data clustering will helps groups during analysis (interesting option  more in the long term)
Native speed, no additional administrative/API layers
S. González

19. Transformative technologies(2)
Other examples:
dq2-get with FTS data transfer. – Robust client tool to fetch data for Tier 3 (no SRM required – not in ToA – a simplification)
Dramatic simplification in cataloguing (local data mgmt)
Storage provides cataloguing info (as in the file system)
Make more local management (e.g. consistency checks) possible
Share local tools
Medium/Longer term examples
PROOF
Efficient data analysis
Virtualization
On top of service aggregation (short term)
Includes Cloud Computing…
Again, IO performance and storage is an interesting issue ($)
S. González

20. Tier3-IFIC Storage in our Tier3 (Lustre) LOCALGROUPDISK T3
60% (around 60 TB)
Under DDM, not quotas T3
40% (around 40 TB)
1-2 TB per user
With quotas
Write enabled from UIs (Seen as local disk)
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21. Tier3-IFIC (Proof Test)
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