Week of 170626

WLCG Operations Call details

  • At CERN the meeting room is 513 R-068.

  • For remote participation we use the Vidyo system. Instructions can be found here.

General Information

  • The purpose of the meeting is:
    • to report significant operational issues (i.e. issues which can or did degrade experiment or site operations) which are ongoing or were resolved after the previous meeting;
    • to announce or schedule interventions at Tier-1 sites;
    • to inform about recent or upcoming changes in the experiment activities or systems having a visible impact on sites;
    • to provide important news about the middleware;
    • to communicate any other information considered interesting for WLCG operations.
  • The meeting should run from 15:00 until 15:20, exceptionally to 15:30.
  • The SCOD rota for the next few weeks is at ScodRota
  • General information about the WLCG Service can be accessed from the Operations Web
  • Whenever a particular topic needs to be discussed at the daily meeting requiring information from site or experiments, it is highly recommended to announce it by email to wlcg-operations@cernSPAMNOTNOSPAMPLEASE.ch to make sure that the relevant parties have the time to collect the required information or invite the right people at the meeting.

Tier-1 downtimes

Experiments may experience problems if two or more of their Tier-1 sites are inaccessible at the same time. Therefore Tier-1 sites should do their best to avoid scheduling a downtime classified as "outage" in a time slot overlapping with an "outage" downtime already declared by another Tier-1 site supporting the same VO(s). The following procedure is recommended:

  1. A Tier-1 should check the downtimes calendar to see if another Tier-1 has already an "outage" downtime in the desired time slot.
  2. If there is a conflict, another time slot should be chosen.
  3. In case stronger constraints cannot allow to choose another time slot, the Tier-1 will point out the existence of the conflict to the SCOD mailing list and at the next WLCG operations call, to discuss it with the representatives of the experiments involved and the other Tier-1.

As an additional precaution, the SCOD will check the downtimes calendar for Tier-1 "outage" downtime conflicts at least once during his/her shift, for the current and the following two weeks; in case a conflict is found, it will be discussed at the next operations call, or offline if at least one relevant experiment or site contact is absent.

Links to Tier-1 downtimes




  • local: Kate (DB, Chair), Maarten (WLCG, ALICE), Tomas J (ATLAS), Paul (storage), Gavin (computing), Vincent (security), Marian B (network)
  • remote: Victor (JINR), Pepe (PIC), Andrew (NL-T1), Chi-Hsun (ASGC), Di Qing (TRIUMF), Dave M (FNAL), John K (RAL), Kyle (OSG), Luca (CNAF), Sang Un (KISTI), Ulf (NDGF), Xin (BNL), David (IN2P3), Zoltan (LHCb)

Experiments round table:

  • ATLAS reports ( raw view) -
    • Activities:
      • large derivation production campaign: replication of the output caused saturation of some links for that special activity. Lot of transfers in queue.
    • Issues:
      • No major issues.

  • CMS reports ( raw view) -
    • Very quiet on our end (as far as I know).
    • A processing backlog developed at T0 but we're working our way through it, not considered a huge problem.
    • Efforts continue to provide good feedback to detector operations.

  • ALICE -
    • continued high activity

  • LHCb reports ( raw view) -
    • Activity
      • User analysis and Monte Carlo simulation
    • Site Issues
      • T0: Jobs in hold state at HTCondor CEs (GGUS:129147)
      • T1:
        • IN2P3: the running jobs are decreasing (GGUS:129141). David commented that this is not related to the downtime issue but to an issue between the CEs and the batch system.
        • RAL: timeout on RAL storage (GGUS:129059)

Sites / Services round table:

  • ASGC: ntr
  • BNL: NTR
  • CNAF:
    • IPV6: xrootd tested and working, ALICE already IPV6, we'll begin deployment for others one at a time. This is only a test deployment as client side is not ready yet.
  • EGI: nc
  • FNAL: ntr
  • IN2P3: IN2P3-CC is wrongly seen in downtime by SAM3 except for CMS (ex.: http://wlcg-sam-lhcb.cern.ch/templates/ember/#/historicalsmry/heatMap?granularity=Hourly&group=Tier%200%2F1&profile=LHCb_CRITICAL&site=LCG.IN2P3.fr&time=7d) Pablo Saiz is aware of this and thinks it is a bug related to the downtime we have registered for our next main maintenance in September.
  • JINR:
    • Configuration of IPv6 on SEs completed.
    • The available space on the tapes is increased to 8000TB.
  • KISTI: All certificates were updated to the new KISTIv3 CA
  • KIT: nc
  • NDGF: DCache update last week didn't work. A retry today didn't work - an issue with draining was discovered. 2 short downtimes will be needed to fix the issue.
  • NL-T1: ntr
  • NRC-KI: nc
  • OSG: ntr
  • PIC: ntr
  • RAL:
    • The increase in our OPN link from 2 * 10Gbit to 3 * 10Gbit should now take place on Wednesday (28th June). It was delayed because the original additional link supplied showed errors.
    • We have had severe problem with our Castor SRMs for Atlas with one of the processes continually crashing. An outage to srm-atlas.gridpp.rl.ac.uk was declared in the GOC DB from Friday to Sunday. On Sunday a fix was applied to filter out double-slashes ("//") in filenames in SRM requests. This was a old fix that had been put into the previous version of the Castor SRM here at RAL. The SRMs have been stable since. We are testing this fix elsewhere, partly to confirm it really is a fix for the problems seen and before rolling it out for the other Castor SRMs.
  • TRIUMF: 6-hour downtime (17:00 - 23:00 UTC) on Monday, June 26:
    • upgrade dCache to 2.16.39;
    • upgrade firmware of network switches;
    • migrate half of cluster from Torque + CREAM CE to HTCondor + ARC CE;
    • and update the OS and kernel on the majority of nodes.

AOB: An update of the vulnerability advisory is expected tomorrow.

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Topic revision: r15 - 2017-06-26 - MaartenLitmaath
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