RAL Tier1 Experiments Liaison Meeting

Wednesday 5 Nov 2025, 13:30 → 15:50 Europe/London

Access Grid (RAL R89)

1 Site Operations

13:34 Experiment Operational Issues

2 ATLAS Operations Report

Speakers: Brij Kishor Jashal (Rutherford Appleton Laboratory), Jyoti Prakash Biswal (Rutherford Appleton Laboratory)

ATLAS liason meeting notes Brij

3 CMS Operations Report

Speaker: Katy Ellis (Science and Technology Facilities Council STFC (GB))

Katy is at the Rucio workshop.

Last week there were some token/ARC-CE tests timing out during the final test in the suite. There was no log file so harder to follow up. The problem went away in a couple of days and hasn't reappeared. 

More job failures than normal, caused by User Analysis. I wrote to one individual who was pulling large (sometimes more than 100GB) inputs per job which were frequently failing, but did not hear back. For now the level of failures has dropped to normal low levels. Overall CPU efficiency remains good. 

Tape writes have been busy, with 2.25PB arriving on Antares in the last 30 days - a lot of data coming from CERN but also the usual rate coming from Echo. This is higher than agreed total rate given the repacking needs. Do we need to pull back a bit or is this fine? Please let me know if we need to reduce. N.B. Failure rate is negligible and everything appears to be working perfectly from CMS side. 

4 LHCb Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

jobs.png

transfers_from.png

transfers_to.png

News:

• pp run is over
  
  

Operational issues:

• DIRAC unable to parse new ARC report format (GGUS:1001002)
  • The format changed in the newest ARC version to be compatible with Glue2 specification (see this buzilla report for details)
  • DIRAC patch was applied to accept new format as well
  • Ticket closed
• Spike of failed user jobs last Saturday
  • The usual problem -- buggy DaVinci (i.e. xrootd) version
  • The user has been contacted before and advised not to use the affected versions..

5 ALICE Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

6 LSST Operations Report

Speakers: Mathew Sims, Timothy Noble (Science and Technology Facilities Council STFC (GB))

14:00 Tier-1 Projects

7 Anatares Upgrade

Speakers: George Patargias, Thomas Byrne

8 XRootD Development

Speakers: Alexander Rogovskiy (Rutherford Appleton Laboratory), Jyothish Thomas (STFC)

EL9 upgrade in progress
streamed checksum PR ready for upstream merge
juno storage ready

9 Utilizing GPUs

Speakers: Jyoti Prakash Biswal (Rutherford Appleton Laboratory), Thomas Birkett

10 SSD Storage Evaluation

14:25 AOB

11 Summary of Operational Status and Issues

Speakers: Brian Davies (Science and Technology Facilities Council STFC (GB)), Darren Moore

Weekly Report 05 November 2025.docx

Weekly Report 05 November 2025.pdf

12 Any other Business

Speakers: Brian Davies (Science and Technology Facilities Council STFC (GB)), Darren Moore