Transcript User Board Overview Dan Tovey University Of Sheffield Dan Tovey, University of Sheffield.

User Board Overview
Dan Tovey
University Of Sheffield
Dan Tovey, University of Sheffield
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
Dan Tovey, University of Sheffield
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
Dan Tovey, University of Sheffield
DB Links
• Stronger links with Deployment Board are
seen as vital  standing invitation for DB
representation at UB meetings.
Dan Tovey, University of Sheffield
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.
Dan Tovey, University of Sheffield
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
Dan Tovey, University of Sheffield
Pleasure: LHCb
Shared data (LHCb RTTC production May/June)
Countries
Events produced
UK
60 M
Italy
42 M
Swiss
23 M
France
11 M
Netherland
10 M
Spain
8M
Russia
3M
Grece
2.5 M
Canada
2M
Germany
0.3 M
Belgium
0.2
Sweden
0.2 M
Romany,Hungary,Brasil,USA
0.8 M
The data reported are
preliminary (accuracy
at 5%)
5% produced with plain
DIRAC sites
95% produced with LCG
sites
Dan Tovey, University of Sheffield
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 …
Dan Tovey, University of Sheffield
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/accounting
Dan Tovey, University of Sheffield
H1 Tests
Dan Tovey, University of Sheffield
H1 Tests
30 Jobs failed: 22 due to Grid problems (gridproxy/misc.)
Dan Tovey, University of Sheffield
H1 Tests
Dan Tovey, University of Sheffield