Week of 170515

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

ALICE	ATLAS	CMS	LHCB
	BNL	FNAL

Monday

Attendance:

• local: Andrei (databases), Gavin (computing), Hervé (storage), Julia (WLCG), Maarten (SCOD + ALICE + GGUS), Marian (networks), Tomas (ATLAS), Vincent (security)
• remote: Chih-Hsun (ASGC), David B (IN2P3), David M (FNAL), Di (TRIUMF), Dimitri (KIT), Dmytro (NDGF), Elena (CNAF), Elizabeth (OSG), FaHui (ASGC), John (RAL), Marcelo (LHCb), Onno (NLT1), Pepe (PIC), Sang-Un (KISTI), Stefano (CMS), Vincenzo (EGI), Xin (BNL)

Experiments round table:

• ATLAS reports ( raw view) -
  • Activities:
    • MC simulation dominating between ATLAS activities
    • preparation for data-taking
  • Issues:
    • problems with delegation of ddm administrator proxy on Friday => transfers were lost for couple of hours
    • consequent issue with transfers on EOS, when proxy was renewed, the authentication queue to/from EOS was overloaded
    • we have observed fast deletion of a file from namespace but slow physical deletion from a pool in few cases of dCache sites
      • similar issue solved here: (GGUS:124751)

• CMS reports ( raw view) -
  • Load on computing grid a bit low due to lack of requests.
  • No major or new problem this week.

• ALICE -
  • Very high activity on average
  • CERN: from Thu ~16:00 to Fri ~14:30 large fractions of the HTCondor jobs failed
    due to absence of the grid account home directory on many WN (GGUS:128287)

• LHCb reports ( raw view) -
  • Activity
    • Stripping v24 waiting for developers. Almost 100k jobs running
  • Site Issues
    • T0:
      • EOS downtime this morning.

Sites / Services round table:

• ASGC: NTR
• BNL: NTR
• CNAF:
  • CREAM ce01-lcg.cr.cnaf.infn.it is being decommissioned
  • CMS file access errors related to IPv6 worked around by disabling GPFS (GGUS:128298)
• EGI: NTR
• FNAL: NTR
• IN2P3: the site will be in maintenance downtime on June 13th, a Tuesday. As usual details will be available one week before the event.
• JINR: NTR
• KISTI: NTR
• KIT: NTR
• NDGF: NTR
• NL-T1: NTR
• NRC-KI:
• OSG: NTR
• PIC:
  • 10% of the capacity has been migrated from Torque to HTCondor
    • in about one week more will be added
    • 100% of the T1 resources are foreseen to be migrated by the end of June
    • the timelines for the T2 resources and the local users are not yet clear
• RAL: There were lots of problems with Castor CMS over the weekend, GGUS:128308. The Castor team are at CERN today and tomorrow.
• TRIUMF:NTR

• CERN computing services:
  • New code 8.6.3 being validated on one HTCondor CE - will roll out soon.
  • Making new HTCondor CEs with a view to move grid capacity fully to HTCondor in near future.
• CERN storage services:
  • EOSLHCB: Upgrade completed this morning, identified an issue with adler32 checksums verification on read: fix is being tested and will enter production right after.
• CERN databases:
  • This week we will be applying OS updates to multiple hosts running database services. All users were notified of the interventions. More details on the CERN SSB.
• GGUS: NTR
• Monitoring:
  • Monitoring:Final reports for the April availability will be distributed tomorrow.
• MW Officer: NTR
• Networks: NTR
• Security: NTR

AOB:

• Please register ASAP for the WLCG workshop held June 19-22 in Manchester!