RAL Tier1 Experiments Liaison Meeting

Wednesday 22 Oct 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 CMS O&C week at CERN.

All stable for CMS this week - SAM tests are green, performance looks good.

As previously reported, Tier 0 data is coming to RAL tape, which hasn't been happening otherwise this year. In last 30 days we received 619TB from Tier 0 directly from CERN to Antares; we also received 462TB of Production Output data which hops via Echo. Total is 1081TB.

For your interest, a total of 1.17PB also landed on Echo (including the 619TB which then hopped to tape).

4 LHCb Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

Operational issues:

• User job failures due to buggy DaVinci version (linked to a buggy xrootd client) last week
  • Users informed about the problem
  • LHCb banned all affected DaVinci versions from Analysis Productions (AP)
    • User jobs are still affected, and there is no easy way to ban certain software version for user jobs
    • Users are encouraged to use AP instead of custom jobs
• Some WNs are using CERN Stratum-1 rather than RAL one
  • That seems to affect ETF tests sometimes (probably CERN Stratum 1 does not do snapshots as often as we do)

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))

• Jobs being killed for OOM, this is an LSST side issue
  • Not requesting enough memory for certain tasks - working with other sites to get this resolved
• Confirmation of effort from RAL for Next Phase of LSST funding
  • Alastair confirming with LSST:UK Bob Mann intent on continued effort for LSST

14:00 Tier-1 Projects

7 Anatares Upgrade

Speakers: George Patargias, Thomas Byrne

8 Utilizing GPUs

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

14:25 AOB

9 Summary of Operational Status and Issues

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

Weekly Report 22 October 2025.docx

Weekly Report 22 October 2025.pdf

10 Any other Business

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