User Board Overview

1
User Board Overview
Dan Tovey University Of Sheffield
2
Tier-1 Planning

• Quarterly UB meeting in April (see minutes)?
  updated Tier-1 planning figures
• Shortfall of T1 resources in future years,
  (especially 2008) evident.
• Will need to consider if expt. requirements can
  be met by Tier-2 resources ? need to demonstrate
  clear need for Tier-1 functionality.
• Requests which can be met by Tier-2 to be
  discussed with Tier-2 board.
• Other Experiments line removed from Tier-1
  Schedule following detailed Tier-1 board plan ?
  all users must make representation to UB to get
  access to resources

3
Tier-1 Planning

• Tier-1 utilisation figures frequently fall
  significantly short of both requests and
  allocations
• sends the wrong message
• Often not fault of experiments (e.g. middleware /
  operational problems) but experiments must work
  to produce more realistic estimates
• Move to strict allocation of Disk resources (no
  over-allocation) ? helps Tier-1 team.
• Also synchronise with spending cycle ? aim to
  ensure complete use of all new resources as soon
  as on-line

4
DB Links

• Stronger links with Deployment Board are seen as
  vital ? standing invitation for DB representation
  at UB meetings.

5
UB Concerns

• How are experiments that globally are not moving
  to the Grid to be handled?
• Site stability User support
• Balance of effort at Tier-1 much used for CMS
  (SRM) and later LCG SC, but what about smaller
  user communities?
• What about non-standard OS at Tier-2 sites ?
  can render useless to some experiments. UB and
  Tier-2 board need to persuade to work towards
  standardisation.

6
Questionnaire

• User Board questionnaire updated for latest OsC
  process.
• No big changes from February
• Some new comments/concerns
• fragmented support structure
• All stick and no carrot
• held up by problems with establishing the VO
• Not all experiments supported by large Tier-2s
• Further details at
• http//www.gridpp.ac.uk/eb/workdoc/gridusebyexpts_
  0605.doc

7
Pleasure LHCb
Shared data (LHCb RTTC production May/June)

• The data reported are preliminary (accuracy at
  5)
• 5 produced with plain DIRAC sites
• 95 produced with LCG sites

8
Pleasure ATLAS

• Using the Grid for 100 of Simulation,
  Digitisation and Reconstruction.
• 8.5M fully simulated ATLAS events produced
• 20 of LCG jobs in UK
• Overall throughput good, and improving

9
Pain ATLAS

• But experience has been painful!
• Significant throughput problems experienced in
  January/February
• production goals descoped (15M events planned vs.
  8.5M ev. actual).
• Identified problems (highlights see also
  questionnaire)
• System appears to function best when only one
  person submitting jobs!
• Lack of a distributed mechanism for prioritising
  jobs
• Lack of inter-operability between LCG and other
  Grids load balancing and data replication have
  to be done 'by hand'. Leads to production errors
  (e.g. same sample produced multiple times on
  different grids)
• Too much human intervention required to set,
  adjust and enforce priorities
• Could not saturate CPU resources on LCG easily
  (rate doubled with a simple change of
  scripts/person!) production time does not scale
  with cpu requirements
• Job definition/submission very (expert) labour
  intensive
• Absolute need for a SE/SRM solution for small
  files.
• Urgent need for VOMS, integrated with other grid
  tools for resource allocation/access/monitoring/ac
  counting

10
H1 Tests
11
H1 Tests
30 Jobs failed 22 due to Grid problems
(gridproxy/misc.)
12
H1 Tests