Difference between revisions of "Tier1 Operations Report 2016-06-15"

Revision as of 10:05, 15 June 2016

RAL Tier1 Operations Report for 15th 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.

• GDSS670 (AliceDisk - D1T0) crashed in the early hours of Sunday morning (12th). Following a disk replacement it was put back in service in read-only mode at the end of Monday afternoon (13th) as another disk was showing media errors. Returned to full production this morning (15th).

• 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.

• None.

• 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.

• 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.

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