Tier1 Operations Report 2016-07-13

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RAL Tier1 Operations Report for 13th July 2016

Review of Issues during the week 6th to 13th July 2016.
  • As reported last week the tape library control software now runs stably with all tape drives enabled. This stability has continued for this last week.
  • There was a problem over the weekend with some CMS writes to tape backed areas failing owing to no tape pool having been defined for these cases. This was resolved on Monday.
  • There has been saturation of the inbound 10Gbit OPN link at times over the last week. The bypass route to JANET has also shown high traffic volumes.
  • We have seen a couple of periods when there have been high numbers of batch jobs started multiple times. There were some on the 7th/8th July and again last night. The cause is not yet understood.
Resolved Disk Server Issues
  • GDSS654 (LHCbRawRdst - D0T1) crashed on Sunday morning, 3rd July. There were eleven files awaiting writing to tape on the server. Three of these were found to be corrupt and were declared lost to LHCb. The server was returned to service on Friday 8th July after two disk drives had been replaced.
  • GDSS730 (CMSDisk - D1T0) reported a read-only filesystem in Wednesday morning, 6th July. It was returned to service on Friday lunchtime, 8th July after a disk was replaced.
  • GDSS619 (GenTape - D0T1) crashed on Sunday 10th July. After some checks it was put back in service the following day (Monday 11th July).
Current operational status and issues
  • There is a problem seen by LHCb of a low but persistent rate of failure when copying the results of batch jobs to Castor. There is also a further problem that sometimes occurs when these (failed) writes are attempted to storage at other sites. A recent modification has improved, but not completed fixed this.
  • The intermittent, low-level, load-related packet loss seen over external connections is still being tracked. Likewise we have been working to understand some remaining low level of packet loss seen within a part of our Tier1 network.
Ongoing Disk Server Issues
  • None.
Notable Changes made since the last meeting.
  • The migration of Atlas data from "C" to "D" tapes continues. We have migrated over 700 of the 1300 tapes so far.
Declared in the GOC DB
  • None
Advanced warning for other interventions
The following items are being discussed and are still to be formally scheduled and announced.

Listing by category:

  • Databases:
    • Switch LFC/3D to new Database Infrastructure.
  • Castor:
    • Update SRMs to new version, including updating to SL6. This will be done after the Castor 2.1.15 update.
    • Update to Castor version 2.1.15. This awaits successful resolution and testing of the new version.
    • Migration of data from T10KC to T10KD tapes (Affects Atlas & LHCb data).
  • Networking:
    • Replace the UKLight Router. Then upgrade the 'bypass' link to the RAL border routers to 2*40Gbit.
  • Fabric
    • Firmware updates on remaining EMC disk arrays (Castor, LFC)
Entries in GOC DB starting since the last report.
  • None
Open GGUS Tickets (Snapshot during morning of meeting)
GGUS ID Level Urgency State Creation Last Update VO Subject
122827 Green Less Urgent In Progress 2016-07-12 2016-07-13 SNO+ Disk area at RAL
122818 Green Less Urgent In Progress 2016-07-12 2016-07-12 Atlas Object Store at RAL
122804 Green Less Urgent In Progress 2016-07-12 2016-07-12 SNO+ glite-transfer failure
122364 Green Less Urgent On Hold 2016-06-27 2016-06-29 cvmfs support at RAL-LCG2 for solidexperiment.org
121687 Yellow Less Urgent On Hold 2016-05-20 2016-05-23 packet loss problems seen on RAL-LCG perfsonar
120810 Green Urgent In Progress 2016-04-13 2016-06-24 Biomed Decommissioning of SE srm-biomed.gridpp.rl.ac.uk - forbid write access for biomed users
120350 Green Less Urgent In Progress 2016-03-22 2016-05-06 LSST Enable LSST at RAL
119841 Red Less Urgent On Hold 2016-03-01 2016-04-26 LHCb HTTP support for lcgcadm04.gridpp.rl.ac.uk
117683 Yellow Less Urgent On Hold 2015-11-18 2016-04-05 CASTOR at RAL not publishing GLUE 2
Availability Report

Key: Atlas HC = Atlas HammerCloud (Queue ANALY_RAL_SL6, Template 729); CMS HC = CMS HammerCloud

Day OPS Alice Atlas CMS LHCb Atlas HC CMS HC Comment
06/07/16 100 100 100 100 100 100 100
07/07/16 100 100 100 100 100 100 100
08/07/16 100 100 100 100 100 100 100
09/07/16 100 100 100 100 100 100 100
10/07/16 100 100 100 100 100 98 100
11/07/16 100 100 100 100 100 100 100
12/07/16 100 100 100 100 100 100 100