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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

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

10. 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

11. 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

12. 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 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