1. Planning for a Western Analysis Facility Richard P. Mount Planning for a Western Analysis FacilityPage 1

2. Planning for a Western Analysis FacilityPage 2 Evaluating US ATLAS Needs Data Production Tasks: BNL Tier 1 (+Tier 2s) meet the pledged requirements Simulation: Could absorb all Tier 2 capacity and more. Physics impact of scaling back is not clear. Analysis: Computing Model allocates 20% to 50% of Tier 2s. Is this realistic quantitatively? Is this realistic qualitatively (data-intensive analysis)? Could Tier 3s provide what appears to be missing?

3. Planning for a Western Analysis FacilityPage 3 US ATLAS T1 + T2 in 2010 Excluding T3s

4. Planning for a Western Analysis FacilityPage 4 BaBar and CDF Excluding “T3s” BaBar Tier As in 2006 (+ simulation done mainly at universities) CDF Fermilab Site in 2008 (thanks to Rick Snider)

5. Planning for a Western Analysis FacilityPage 5 Data-Intensive Analysis 1.Babar (and Run II) experience demonstrated a vital role for major “Tier-A” computer centers specializing in high-throughput data- intensive work. 2.Physics demands chaotic, apparently random access to data. This is a hardware/software/management challenge. 3.Achieving high-availability with a complex data-intensive workload is hard! 4.Running simulation at major data-intensive facilities fails to exploit them fully (BaBar ran most simulation on university facilities). 5.Significant university (Tier 3) facilities have always been very important for final-stage analysis.

6. Planning for a Western Analysis FacilityPage 6 SLAC Strengths 1.Pushing the envelope of Data Intensive Computing e.g. Scalla/xrootd (in use at the SLAC T2) 2.Design and implementation of efficient and scalable computing systems (1000s of boxes) 3.Strongly supportive interactions with the university community (and 10 Gbits/s to Internet2). Plus a successful ongoing computing operation: Multi-tiered multi-petabyte storage ~10,000 cores of CPU Space/power/cooling continuously evolving

7. Planning for a Western Analysis FacilityPage 7 SLAC Laboratory Goals 1.Maintain, strengthen and exploit the Core Competency in Data Intensive Computing; 2.Collaborate with universities exploiting the complementary strengths of universities and SLAC.

8. Planning for a Western Analysis FacilityPage 8 ATLAS Western Analysis Facility Concept 1.Focus on data-intensive analysis on a “major-HEP-computing- center” scale; 2.Flexible and Nimble to meet the challenge of rapidly evolving analysis needs; 3.Flexible and Nimble to meet the challenge of evolving technologies: Particular focus on the most effective role for solid state storage (together with enhancements to data-access software); 4.Close collaboration with US ATLAS university groups: Make best possible use of SLAC-based and university-based facilities. 5.Coordinate with ATLAS Analysis Support Centers.

9. Planning for a Western Analysis FacilityPage 9 ATLAS Western Analysis Facility Possible Timeline 1.Today: Interest from “Western” ATLAS university groups in co- locating ARRA-funded equipment at SLAC (under discussion). 2.2010: Tests of various types of solid-state storage in various ATLAS roles (conditions DB, TAG access, PROOF-based analysis, xrootd access to AOD …). Collaborate with BNL and ANL. 3.2010: Re-evaluation of ATLAS analysis needs after experience with real data. 4.2011 on: WAF implementation as part of overall US ATLAS strategy.