UK MoUs and Tier-1/A experiment shares principles of sharing

The Grid is about sharing The Grid is about sharing.. We are being asked to determine long-term shares for the Tier-1/A by each of the LHC experiments - we need to agree some basic principles (at this meeting), hence this is cast as a proposal for debate 14 September 2004 GridPP1 and AHM

Tier-1/A priorities The principle aim of setting up GridPP was to create an environment where ALL PP users gained from the (unique) level of support at a single Tier-1/A centre The required scale and the overall case was driven by the LHC data handling requirements The UK is now being asked to present fractions by (LHC) experiment for Tier-1 use.. (by October 19th) 14 September 2004 GridPP1 and AHM

Tier-1/A priorities The Tier-1/A centre is the only part of GridPP ~wholly owned within GridPP GridPP UB priorities are: to (be able to) use the Grid Within this Data Analysis Monte Carlo production (since this can be provided at Tier-2) Q: Do all users agree on this hierarchy? 14 September 2004 GridPP1 and AHM

Tier-1/A Board The Tier-1/A Board constitution was recently extended to incorporate International MoU advice to PPARC (anticipating GridPP PMB per se will not exist post-September 2007) Accordingly, the Tier-1/A Board constitution was extended Q: is the UB content that it should “agree general principles” and these can then be represented by both the Chair and the Deputy Chair of the UB at the Tier-1/A Board meetings? 14 September 2004 GridPP1 and AHM

Background A lot has been written in various documents over the summer establishing: a UK position w.r.t. the LCG MoUs; and the total resources anticipated at the Tier-1/A UK report to the LCG POB UK input to Phase-2 planning GridPP2 International MoUs and Experiment Allocations Each built upon the knowledge at that time, but none addressed the basic principles of how long-term sharing would be “managed” 14 September 2004 GridPP1 and AHM

What have we stated so far? The UK has no firm plans for how the resources outlined above will be shared between the LHC experiments: this will be discussed at the next Tier-1 Board meeting on October 27th but may not be concluded in the timeframe of the pre-MoU planning cycle. All that can currently be said is that UK baseline support for LHC experiments will likely be proportional to the number of UK names appearing on LHC papers. It is clear that the current level of resources at the Tier-1/A centre cannot meet the combined aspirations of the LHC experiments as well as BaBar and other experiments esp. from 2007 onwards. It is hoped that efficient use of Tier-1/A and Tier-2 centre resources will, however, enable all agreed targets to be met. 14 September 2004 GridPP1 and AHM

Proposal The principle driving resource allocations is The UK’s fractional contribution to each experiment’s physics output This is a long-term issue requiring standardised and widely accepted metrics (or a “smoke-filled room” approach) Established measures for M&O of experiments are fractions of (non-student) authors on papers UK aim: meet the minimum and go beyond this Q: Is the UB content with using (M&O) authorship as a way of establishing a baseline for all experiments? 14 September 2004 GridPP1 and AHM

Proposed Baseline Metric Driven by experiment: #(Expt_UK)/#(Expt) * Expt_Total_Compute_Tier-1 = Expt_UK_Compute_Tier-1 Q: Does the UB have a view that differs from this? 14 September 2004 GridPP1 and AHM

Further metrics The principles driving resource allocations beyond a baseline could be: Driven internally by each country? #(Expt_UK)/#(UK) Where # = (M&O) author numbers PRSC alpha grade weighting? a measure of peer-review The UK’s fractional contribution to each experiment’s output Driven externally e.g. by a given experiment providing compensation through its overall M&O (c.f. BaBar). 14 September 2004 GridPP1 and AHM

LCG MoU status For LHC, the external driver is the LCG overall (through the LCG MoU in preparation with each country) Hence each country is being asked this question individually as a starting point This will then be built into the overall LCG MoU Further checks and balances will be made.. 14 September 2004 GridPP1 and AHM

Computing MoUs The Computing-RRB in October 2003 requested establishment of a Taskforce to agree on document structure and content, and to draft document(s) for approval The taskforce has met face-to-face four times, most recently on 31 August, with extensive email dialog between the meetings. It will meet again on 28 September during the Computing in High Energy Physics (CHEP) conference (27 Sept - 1 Oct), with the aim of finalising the bodies of the texts at that meeting. The texts will then be presented to the October RRB for comment, and the numerical data in the Annexes will be completed over the Winter so that the final documents can be presented to the April 2005 RRB for approval and subsequent distribution for signature