RAL Tier1 Experiments Liaison Meeting

Wednesday 25 Jun 2025, 13:30 → 15:50 Europe/London

Access Grid (RAL R89)

13:30 Experiment Operational Issues

1 ATLAS Operations Report

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

ATLAS liason meeting notes Brij

2 CMS Operations Report

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

Apologies from Katy - attending the OTF.

Good SAM tests this week. A short period of failures Tuesday evening on Antares, due to filling of buffer. There was a big spike in both write successes and write failures - CMS still hit a very high throughput to the buffer and files were quickly archived. 

SAM test warnings fixed for the 'squid' tests - thanks Alex for tracking this!

Still seeing the 'basic' token test in warning when it lands on 18/19 WN tranches (currently around 50% of the time) - this is due to missing IPv6 on those nodes, but CMS seems happy to keep the test in warning. 

Good performance for CMS jobs - best CPU efficiency among T1s for this week again!

3 LHCb Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

News:

• LHCb is going to run some test MC productions on ARM
  • at CERN and Glasgow

 

Operational issues:

• Jobs failed to get files from Echo via local gateways (GGUS 683524).
  • connectivity issue between 201[89] gens and new storage node, fixed
  • Last Friday a slow OSD also contributed to this issue
    • It was removed from the cluster, that fixed the issue
• Failed uploads to ECHO last Friday (GGUS 683588).
  • One of the gateways became problematic due to stuck connections. It was fixed by restarting the gateway. Ticket closed.

4 ALICE Operations Report

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

5 LSST Operations Report

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

• First Look event on Monday 23rd June
  • https://www.bbc.co.uk/news/articles/cj3rmjjgx6xo
  • https://www.youtube.com/live/dF1g-Ru8mjM
  • https://rubinobservatory.org/news/first-imagery-rubin
  • https://rubinobservatory.org/explore/citizen-science
  • Should be de-embargoing data now, so more data to move to the UK moving forwards

 

• RC2 runs have not been succeeding due to no outputs from jobs after 2 hours
  • Think this may boil down to a similar issue we saw before with the Quantum Graph issue (if not exactly the same issue) 
    • not pulling data into WN, just remote reading small portions over and over and over (peak was over 250,000 times for one job)
  • Coordinating with Jyothish for the XRootD monitoring that died to investigate file by file access patterns
•  

14:00 Tier-1 Projects

6 Anatares Upgrade

New EOS nodes
Repack Progress

Speakers: George Patargias, Thomas Byrne

7 XRootD Development

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

streamed checksum data collection in progress, ceph-gw9 in prep for getting added to prod

 

8 Utilizing GPUs

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

14:45 AOB

9 Summary of Operational Status and Issues

Speakers: Brian Davies (Lancaster University (GB)), Darren Moore

Weekly Report 25 June 2025.docx

Weekly Report 25 June 2025.pdf

10 Any other Business

Speakers: Brian Davies (Lancaster University (GB)), Darren Moore