RAL Tier1 Experiments Liaison Meeting

Wednesday 20 May 2026, 13:30 → 15:50 Europe/London

Access Grid (RAL R89)

13:30 → 13:34 Site Operations

13:34 → 13:35 Experiment Operational Issues

13:35 → 13:40 ATLAS Operations Report

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

Brij ATLAS liason meeting notes

13:40 → 13:45 CMS Operations Report

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

13:45 → 13:50 LHCb Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

Operational issues:

• S3 storage outage at CERN on Monday
  • Production Sandbox SE was unavailable as a result, new jobs were unable to start
  • Fixed within a couple of hours
• Problem with MCFastSimulation is still present
  • Jobs incorrectly estimate the required completion time, and killed by pilot as a result
  • LHCb promised to increase time estimates, which should help
• Dark data found at Antares
  • To be removed

13:50 → 13:55 ALICE Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

• Alice gateway ceph-svc04 is not accessible from lxplus via IPV6
  • GSTSM-742

13:55 → 14:00 LSST Operations Report

Speakers: Thomas Birkett, Timothy Noble (Science and Technology Facilities Council STFC (GB))

• Date movement to RAL for UK test initially fast, then stalled!
  • Seems to be a bug in Rucio when using large containers which have over 1 million files
    • Submitted rucio rules for each of the datasets instead, waiting for Rucio to figure out what it needs to do
• Jobs for HSC multisite at RAL running well - 
  
• Data transfer of raw files back on to RAL - 9 TB
  

14:00 → 14:01 Tier-1 Projects

14:08 → 14:13 XRootD Development

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

xrootd 5.9.4 is out, has a critical bug, so we're skipping it for 5.9.5
https://github.com/xrootd/xrootd/issues/2797

SRR format:
wlcg format has an additional "servicetype":"org.wlcg.se", entry that needs adding
splitting datadisk and scratchdisk is going to be trickier while keeping them in the same pool
publishing the SRR once a day should be feasible, but needs testing.

14:14 → 14:19 Utilizing GPUs

Speakers: Dr Brij Kishor Jashal (Rutherford Appleton Laboratory), Thomas Birkett

14:25 → 14:26 AOB

14:27 → 14:36 Summary of Operational Status and Issues

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

Weekly Report 20 May 2026.docx

Weekly Report 20 May 2026.pdf

14:45 → 14:50 Any other Business

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