Tier1 Operations Report 2016-06-08

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RAL Tier1 Operations Report for 8th June 2016

Review of Issues during the week 1st to 8th June 2016.
  • There have been significant problems with the tape library in this last week. There was an intervention on Wednesday (1st June) to fix some outstanding hardware issues. This included changing one of the 'handbots'. The library has a feature whereby a handbot can be moved outside a safety door so that it can be worked on while the rest of the library is running. However, what appears to have been a fault in the replacement unit caused a short. The original unit was replaced - the library passed its power-up tests and ran overnight. A safety issue was flagged and the library was taken down from Thursday (2nd June) until Friday (3rd) so it could be checked. Also on Friday the original handbot was swapped out with another replacement unit. At the end of Friday all hardware components on the library were working OK. The library worked reasonably over the weekend, although the control software (which has been running on a spare system) has been crashing a few times per day. Yesterday (Tuesday 7th June) we moved back to running the control software on the 'production' server and restarted services slowly after that had come up. The software has been stable since then.
  • We are seeing high usage of the OPN link to CERN with the inbound traffic saturating the 10Gbit link for several periods (of some hours each) within the week.
Resolved Disk Server Issues
  • None
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
  • GDSS650 (LHCbUser - D1T0) crashed on Monday morning. It is undergoing checks ahead of being returned to service. A RAID array verify, which completed last night, threw up another failed disk. This was replaced this morning (8th June) and we are allowing the rebuild to proceed before returning to service.
Notable Changes made since the last meeting.
  • LCGWMS06 was stopped from accepting new work as part of its decommissioning process.
  • The migration of Atlas data from "C" to "D" tapes is ongoing. We have migrated around 450 of the 1300 tapes so far.
  • This morning the "production" FTS3 instance was upgraded to version 3.4.6.
Declared in the GOC DB
Service Scheduled? Outage/At Risk Start End Duration Reason
lcgfts3.gridpp.rl.ac.uk, SCHEDULED WARNING 08/06/2016 10:00 08/06/2016 11:00 1 hour Upgrade of FTS3 service to version 3.4.6
lcgwms06.gridpp.rl.ac.uk, SCHEDULED OUTAGE 01/06/2016 11:00 30/06/2016 11:00 29 days, Server lcgwms06.gridpp.rl.ac.uk Decommissioning
Advanced warning for other interventions
The following items are being discussed and are still to be formally scheduled and announced.
  • Decommissioning of "GEN Scratch" storage in Castor. (Formally announced by EGI broadcast). Write access to this area has now been stopped in preparation for completely stopping access on the 20th June.
  • Decommissioning of lcgwms06. This has stopped receiving new work ahead of full withdrawal.

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)
  • Grid Services
    • Once the use of the Load Balancer (HAProxy) has been proven for the test FTS service it will be extended to other services.
Entries in GOC DB starting since the last report.


Service Scheduled? Outage/At Risk Start End Duration Reason
lcgfts3.gridpp.rl.ac.uk, SCHEDULED WARNING 08/06/2016 10:00 08/06/2016 11:00 1 hour Upgrade of FTS3 service to version 3.4.6
All Castor endpoints (SRM) with tape. UNSCHEDULED WARNING 07/06/2016 09:00 07/06/2016 14:00 5 hours Tape system unavailable during investigation into crashes of the tape library control software.
All Castor endpoints (SRM) with tape. UNSCHEDULED WARNING 03/06/2016 13:00 03/06/2016 17:26 4 hours and 26 minutes Ongoing Problem with Tape Library. No tape access during this afternoon.
All Castor endpoints (SRM) with tape. UNSCHEDULED WARNING 02/06/2016 11:00 03/06/2016 13:00 1 day, 2 hours Tape library not available - no tape access
lcgwms06.gridpp.rl.ac.uk, SCHEDULED OUTAGE 01/06/2016 11:00 30/06/2016 11:00 29 days, Server lcgwms06.gridpp.rl.ac.uk Decommissioning
All Castor endpoints (SRM) with tape. SCHEDULED WARNING 01/06/2016 10:00 01/06/2016 15:00 5 hours Expected Break in Tape Access for Around Two Hours During this Time Window while Engineer Attends Tape Library.
Open GGUS Tickets (Snapshot during morning of meeting)
GGUS ID Level Urgency State Creation Last Update VO Subject
121894 Green Top Priority in Progress 2016-06-01 2016-06-01 Tier-1 LHCOPN IPv6 Peering, incl. dualstack Perfsonar
121687 Green Less Urgent On Hold 2016-05-20 2016-05-23 packet loss problems seen on RAL-LCG perfsonar
120810 Amber Urgent In Progress 2016-04-13 2016-05-24 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
01/06/16 100 100 100 100 100 100 75
02/06/16 95.8 100 100 100 100 100 100 Looks like transitory problem with site BDII,
03/06/16 100 100 100 100 100 100 100
04/06/16 100 100 100 100 100 98 100
05/06/16 100 100 100 100 100 100 N/A
06/06/16 100 100 100 100 100 96 100
07/06/16 100 100 100 100 100 100 100