RAL Tier1 Experiments Liaison Meeting

Wednesday 20 Mar 2024, 13:30 → 15:00 Europe/London

Access Grid (RAL R89)

14:00 Major Incidents Changes

1 Summary of Operational Status and Issues

Speakers: Brian Davies (Lancaster University (GB)), Darren Moore, Kieran Howlett (STFC RAL)

Weekly Report 20 March 2024 .docx

Weekly Report 20 March 2024 .pdf

2 GGUS /RT Tickets

https://tinyurl.com/T1-GGUS-Open
https://tinyurl.com/T1-GGUS-Closed

3 Site Availability

https://lcgwww.gridpp.rl.ac.uk/utils/availchart/

https://cms-site-readiness.web.cern.ch/cms-site-readiness/SiteReadiness/HTML/SiteReadinessReport.html#T1_UK_RAL

http://hammercloud.cern.ch/hc/app/atlas/siteoverview/?site=RAL-LCG2&startTime=2020-01-29&endTime=2020-02-06&templateType=isGolden

14:05 Experiment Operational Issues

4 VO Liaison CMS

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

Gateway tests 19thMarch.pdf

Katy at computing week. Nothing special to report in addition to the slides. 

5 VO-Liaison ATLAS

Speakers: James William Walder (Science and Technology Facilities Council STFC (GB)), Jyoti Prakash Biswal (Rutherford Appleton Laboratory)

• Post-DC24 test @RAL:
  • GGUS-165529
    • T0-T1 test repetition (RAL-LCG2); in progress.
    • Test went ahead on 18 March around 13:30 hrs (UK time).
    • During the first 2-3 hours, the traffic was regular and writing happened at a rate of 28.6 Gb/s.
    • FTS parameters were changed to achieve the desired rate (44 Gb/s), but the rates went down.
    • Concerning deletions: 
      • The tape is not like disk and files are not actually deleted but their id in the catalogue is. 
      • The degradation due to deletions is an artefact of how the test is run, not of the performance of the tape system.
      • The files can't simply be overwritten -- this was not realised before the test.
      • Enough space is needed on 20 March for at least about 6 hours to avoid this to happen. 
    • Asked of RAL: observation about tape rates, deletion and network 13:40 and 17:00 UTC to be posted on the ticket.
  • Monit-grafana link:
    • There were deletion "failures", but no deletion error was found! 
      

 

• lcg2483.gripp.ac.uk
  • RAL-LCG2_TEST -- 
    
    • Things are fairly good -- HammerCloud tests look good. 
      
    • Job Accounting link.
    • The workernode link.

 

• New tape family discussions: STAH-76.

6 VO Liaison LHCb

Speaker: Alexander Rogovskiy (Rutherford Appleton Laboratory)

LHCb:

• Checksum ticket closed
• Requested to add disk buffer information to atnares SRR
• Lost files on Antares during DC24
  • Investigation is ongoing, requested help from Antares team

Alice:

• TPC issue
  
  • Keepalive config was rolled out to Antares prod instance
    
    • No failures since the roll out

7 VO Liaison LSST

Speaker: Timothy John Noble (Science and Technology Facilities Council STFC (GB))

8 VO Liaison Others

14:31 AOB

9 Any other Business

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