RAL Tier1 Experiments Liaison Meeting

Wednesday 29 Apr 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)

13:40 → 13:45 CMS Operations Report

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

Very little to report from CMS.

I saw the GGUS ticket (https://helpdesk.ggus.eu/#ticket/zoom/1002467) from ATLAS reporting some failing transfers between Antares and Echo, but does not appear to have affected CMS as yet.

Still on my to-do list: deal with the /unmerged/ files that are not deleted.

13:45 → 13:50 LHCb Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

There were a few issues at CERN that affected the LHCb performance across the grid:

• Late host certificate renewal on the CERN IAM server
  • We use long-lived proxies, lifetime is usually up to 5 days
  • Host certificate was renewed 1 day before the expiration
  • VOMS ACs have IAM server cert embedded into them.
  • Therefore proxies, generated up to 4 days before renewal, expired simultaneously with the host certificate
    • That caused lost of job and transfer failures
• Problem with pilot time-management system after new dirac release last Thursday
  • Buggy pilots are unable to do time management properly, causing many job failures
  • The problem is still present to some extent since our pilots are long-lived and some buggy ones still remain in the system.
• Problems with DIRAC FileCatalogue and SandboxSE this morning
  • Overloaded server
  • Resulted in a spike of completed and rescheduled jobs

 

On the positive side, RAL Tier-1 performance was OK during the last two weeks.

 

13:50 → 13:55 ALICE Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

xrootd accounting is fixed, should we ask ALICE to remove excess data from ECHO?

13:55 → 14:00 LSST Operations Report

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

• Running old pipeline (hsc_pdr2_multisite) as dp2_prep has been discontinued due to the excessive storage requirements for a single run - may be returned to once outputs are addressed
• Blips in jobs due to PanDA going down at SLAC - otherwise RAL is running well for the hsc_pdr2_multisite jobs
• 
• Raw data still flowing to RAL in preparation for DP2 and DR1 (14TB in last week) - total on Echo now approaching 1PB of 10PB quota
  • Still need to identify the files which are on Echo and not needed - CM team US and UK have been busy dealing with the over subscription of Lancs due to DP2_prep outputs
    

14:00 → 14:01 Tier-1 Projects

14:08 → 14:13 XRootD Development

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

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 29 April 2026.docx

Weekly Report 29 April 2026.pdf

14:45 → 14:50 Any other Business

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