Week of 161128

WLCG Operations Call details

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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

ALICE ATLAS CMS LHCB
  BNL FNAL  

Monday

Attendance:

  • local: Luca (SCOD), Hugo (Storage), Maarten (ALICE), Andrew (LHCb), Julia (WLCG), Maria A. (WLCG+CMS), Marian (Network), Jose (DB), Alberto (Monitoring), Gavin (Computing), Andrea M. (MW), Vincent (Security)
  • remote: Andrzej (ATLAS), Christoph (CMS), Kyle (OSG), Di (TRIUMF), Dimitri (KIT), Jose (PIC), John (RAL), David (FNAL), Dmytro (NDGF), Onno (NL-T1), Rolf (IN2P3), FaHui (ASGC), Sang-Un (KISTI), Victor (JINR)

Experiments round table:

  • ATLAS reports (raw view) -
    • Reprocessing of physics delayed stream finishing successfully
    • Big production of DAOD derivations on 2015/2016 pp data started.
      Share for group production increased again to cope with large production.
    • CVMFS services were partially unavailable at 2 sites, ASGC and RAL, on Friday, Nov 25 evening.
      RAL was fixed quickly after starting cron job for updates.
      Later ASGC solved issues with instabilities on link to CERN. Since then has been running well.

  • CMS reports (raw view) -
    • CRC slot has been shared between Stefano & Christoph
    • Heavy Ion Run is ongoing
      • So far no major issues on the Computing side
      • Moving towards the DAQ limits in order to collect maximum number of events
    • MC production
      • Moved T2 fair-share target from 50%:50% to 75%:25% favoring Production over Analysis
      • Have difficulties to keep up with staging GEN-SIM input
    • One bad WN at GRIF produced corrupted files for CMS GGUS:125142

  • ALICE -
    • Experienced the same issue as ATLAS with the Stratum-1 at RAL, also during the weekend

  • LHCb reports (raw view) -
    • Activity
      • Monte Carlo simulation, data reconstruction/stripping and user jobs on the Grid
    • Site Issues
      • T0: NTR
      • T1:
        • CNAF: Some transfer issues over the weekend (GGUS:125208). All fixed now!

Sites / Services round table:

  • ASGC: NTR
  • BNL:
  • CNAF: NTR
  • EGI:
  • FNAL: NTR
  • GridPP:
  • IN2P3: reminder of the outage on December 6th. Batch will already be draining the night before, dCache will be down all day. Some services might run with lower performance until the 7th in the evening. Details will be published in the downtime declarations on coming Wednesday afternoon. CMS transfers failed from Thursday to Monday due to a certificate problem. The vobox of ALICE was overloaded and crashed Saturday night, restarted on Sunday morning, is now up and running.
  • JINR: Backlog in tape reading queue dropped from 40,000 files to 6000 in the local dCache tape queue. Still trying to optimize dCache+Enstore for reading from tapes.

  • CERN computing services: NTR
  • CERN storage services:
    • CERN AFS external disconnection test for 24h on 11 Jan 2017 from 9:00. More info here: OTG:0034398
  • CERN databases: Archive log compression was enable last week to CMSONR ADG databases in order to work around P5-CC network issues causing a lag.
  • GGUS: Release this Wed 30/11 with ALARM tests as usual.
  • Monitoring: NTR
  • MW Officer:
    • glite-yaim-core-5.1.4-1 released to WLCG repo ( and under integration in UMD). It fixes GGUS:125108 + C7/SL7 support
    • glite-yaim-clients-5.2.1-1 released to WLCG repo. It fixes some issues related to WLCG VOBOX
  • Networks:
    • Two scheduled maintenance on one CERN-WIGNER link:
      • 28 Nov from 15:00 to 20:00
      • 29 Nov from 15:00 to 20:00
  • Security: No news on CVE-2016-7117 for RHEL.

AOB:

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Topic revision: r17 - 2016-11-28 - MaartenLitmaath
 
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