RAL Tier1 Operations Report for 3rd August 2016
| Review of Issues during the week 27th July to 3rd August 2016.
|
- There has been more saturation of the inbound 10Gbit OPN link. There was a respite during the LHC stop last week - but the data flows have picked up again this week. We will reconfigure to use both links, effectively upgrading to a 20Gbit connection, tomorrow (4th Aug).
- There was a problem with the GEN Castor GEN instance caused by a particular disk server late on Saturday evening, 30th July. This was fixed by the oncall team. There was an effect on ALICE SAM tests of the SE for a while around midnight.
| Resolved Disk Server Issues
|
- GDSS675 (CMSTape D0T1) was returned to service on Thursday (28th July). It had been taken out of service on Tuesday (26th July) when a second disk failure while the first one was being rebuilt.
| 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
|
- GDSS634 (AtlasTape, doT1) crashed on Friday afternoon 29th July. There were four files awaiting migration to tape on the server. These were copied off on Saturday (30th). This server has crashed before and is being thoroughly checked out - including swapping all its disk drives, before it is returned to production.
| Notable Changes made since the last meeting.
|
- The database behind the LFC was moved to new hardware on Monday (1st Aug).
- The 2009 worker nodes are being drained from the batch system ahead of their use as tests systems before final decommissioning.
- The migration of Atlas data from "C" to "D" tapes continues. We have migrated over 1100 of the 1300 tapes so far.
| Advanced warning for other interventions
|
| The following items are being discussed and are still to be formally scheduled and announced.
|
- The configuration of the OPN connection to CERN will be changed tomorrow (Thursday 4th August) to make use of both links. This will effectively give an upgrade from 10 to 20Gbit.
Listing by category:
- 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 older disk servers.
| Entries in GOC DB starting since the last report.
|
| Service
|
Scheduled?
|
Outage/At Risk
|
Start
|
End
|
Duration
|
Reason
|
| lfc.gridpp.rl.ac.uk, lfc.gridpp.rl.ac.uk,
|
SCHEDULED
|
WARNING
|
01/08/2016 12:00
|
01/08/2016 17:00
|
5 hours
|
RAC Oracle backend migration to new hardware
|
| lfc.gridpp.rl.ac.uk, lfc.gridpp.rl.ac.uk,
|
SCHEDULED
|
OUTAGE
|
01/08/2016 09:00
|
01/08/2016 12:00
|
3 hours
|
RAC Oracle backend migration to new hardware
|
| Open GGUS Tickets (Snapshot during morning of meeting)
|
| GGUS ID |
Level |
Urgency |
State |
Creation |
Last Update |
VO |
Subject
|
| 122827
|
Green
|
Less Urgent
|
Waiting Reply
|
2016-07-12
|
2016-07-27
|
SNO+
|
Disk area at RAL
|
| 122364
|
Green
|
Less Urgent
|
In Progress
|
2016-06-27
|
2016-07-15
|
|
cvmfs support at RAL-LCG2 for solidexperiment.org
|
| 121687
|
Amber
|
Less Urgent
|
On Hold
|
2016-05-20
|
2016-05-23
|
|
packet loss problems seen on RAL-LCG perfsonar
|
| 120350
|
Green
|
Less Urgent
|
Waiting Reply
|
2016-03-22
|
2016-07-26
|
LSST
|
Enable LSST at RAL
|
| 119841
|
Red
|
Less Urgent
|
On Hold
|
2016-03-01
|
2016-08-02
|
LHCb
|
HTTP support for lcgcadm04.gridpp.rl.ac.uk
|
| 117683
|
Amber
|
Less Urgent
|
On Hold
|
2015-11-18
|
2016-04-05
|
|
CASTOR at RAL not publishing GLUE 2
|
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
|
| 27/07/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 28/07/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 29/07/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 30/07/16 |
100 |
94 |
100 |
100 |
100 |
100 |
100 |
Failed "AliEn-SE test": Problem on single disk server in AliceDisk causing blockage. Picked up by our functional test.
|
| 31/07/16 |
100 |
97 |
100 |
100 |
100 |
100 |
100 |
Continuation of above.
|
| 01/08/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 02/08/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
