Week of 170925

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: Luca (SCOD+Storage), Kate (DB), Vincent (Security), Andrea (MW), Marian (Network), Raja (LHCb)
  • remote: David C. (ATLAS), Jean-Roch (CMS), Chi (ASGC), Xin (BNL), Luca L. (CNAF), David M. (FNAL), David B. (IN2P3), Victor (JINR), Dmitry (KIT), Jens (NDGF), Onno (NL-T1), Kyle (OSG), Pepe (PIC), Gareth (RAL), Di (TRIUMF), Sang Un (KISTI)

Experiments round table:

  • CMS reports ( raw view) -
    • Overall good CPU utilization last week: peak ~180k ~140k cores for production + ~40k for analysis
    • T0 heavily used for production
    • Moving production to 8-thread jobs as much as possible
    • On-going investigation on tape-recall activity (RAL, CNAF)
    • /store/unmerged/ area being cleaned too aggressively (T1-T2), hand-shaking on the policy
    • glidein at KIT GGUS:130585 CMS needs to be more gentle with local queue
    • transfer to IN2P3 failing GGUS:130660 impacting CMS

  • ALICE -
    • Apologies: ALICE operations probably cannot join today
    • Continued very high activity on average
    • CERN:
      • EOS-ALICE namespace crash Fri morning (OTG:0039923)
      • CASTOR-ALICE transfer timeouts most of Fri (OTG:0039938)
      • We thank the storage experts for their efforts!

  • LHCb reports ( raw view) -
    • Activity
      • Monte Carlo simulation, data processing and user analysis (running more than 100K jobs)
    • Site Issues
      • T1:
        • Failed transfers from IC to SARA (IPV6) (GGUS:129946); Problem probably in SARA connection to LHCOne
          • Onno: workaround in place; GGUS ticket updated.
        • Problem downloading from SARA (GGUS:130692). Solved promptly by SARA - thanks. Problem with stuck dCache space manager
      • T2:
        • Problems with pilots failing to contact LHCb services at CERN from WNs at Liverpool (GGUS:130715)

Sites / Services round table:

  • BNL: NTR
  • CNAF:
    • on october 2nd an upgrade to the main link could cause a down of the network already in GOCDB as "at risk"
    • we'll enable IPv6 for all experiments with the following timeline:
      • experiment // xrootd // gridftp // storm
      • CMS: 5/10 // 10/10 // 11/10
      • ATLAS: 17/10 // 18/10 // 24/10
      • LHCB: - // 25/10 // 26/10
  • EGI:
  • IN2P3: NTR
  • KIT: NTR
  • NL-T1:
    • dCache collapsed last Thursday evening with SpaceManager communication problems. It was fixed Friday morning with a restart of the SpaceManager. GGUS:130691 and GGUS:130692
    • We'll do a change in the dCache authentication config Tuesday around 10:00 CEST. This should be transparent, but if it causes problems, please shout and we'll roll back. GOC:24027
    • The SARA worker nodes will migrate to Centos 7 soon, possibly on October 3 and 4.
  • NRC-KI:
  • OSG: NTR
  • PIC: NTR
  • RAL: NTR

  • CERN computing services: N/A
  • CERN storage services: NTA
  • CERN databases:
    • issue with the Active Data Guard of the CMS DB (seems network related)
  • Monitoring: NTR
  • MW Officer: While investigating FTS transfers issues to a couple of DPM sites, we discovered that they are still running on SL5. ( EOL in March 2017). Please make sure to move out from SL5 ASAP.
  • Networks: IC/SARA - SARA is investigating and have involved their network vendor for support (GGUS:129946)
  • Security: NTR


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Topic revision: r16 - 2017-09-26 - OnnoZweersExternal
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