RAL Tier1 Operations Report for 30th March 2016
| Review of Issues during the week 23rd to 30th March 2016.
|
- There was a network problem that started on Thursday evening, 24th March shortly after 19:00 and was fixed during the following day (at around 14:00). This was traced to one of the four links from the Tier1 core network to the UKLight router partially failing. This was resolved remotely (Friday 25th being a holiday).
- There was another network problem yesterday evening (Tuesday 30th March) between around 18:30 and 21:00. One of the RAL site routers had a problem and link between it and the primary of our Tier1 router pair was flapping. There should have been an automatic failover to our secondary router - but owing to a configuration error that did not happen. Staff attended on site to force the failover which resolved the problem.
| Resolved Disk Server Issues
|
- GDSS620 (GenTape - D0T1) Reported a read-only file system on the 15th March and was taken out of production. Two T2K files that were not yet copied to tape were corrupt and have been reported as lost. Investigations showed problems with three disk drives. The server was returned to production this morning (30th March).
| 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.
- The draining of Castor disk servers is very slow. We need to drain a few old servers to provide spares - this being part of the deployment plan and server lifecycle. This does not yet impact services but is being followed up.
| Ongoing Disk Server Issues
|
- GDSS635 (AtlasTape - D0T1) Crashed on Saturday (26th March) and was taken out of production. There were no files awaiting migration to tape. Work is still ongoing checking this system.
| Notable Changes made since the last meeting.
|
- Remaining patching and rebooting for security updates.
None
| Advanced warning for other interventions
|
| The following items are being discussed and are still to be formally scheduled and announced.
|
- The Castor 2.1.15 update is pending. Testing has shown a database related performance issue which is being followed up. We await successful resolution of that problem and completion of testing before scheduling.
- Decommissioning of "GEN Scratch" storage in Castor.
Listing by category:
- Databases:
- Switch LFC/3D to new Database Infrastructure.
- Castor:
- Update SRMs to new version (includes updating to SL6).
- Update to Castor version 2.1.15.
- 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*10Gbit.
- Fabric
- Firmware updates on remaining EMC disk arrays (Castor, LFC)
- Grid Services
- A Load Balancer (HAProxy) will be used in front of the FTS service.
| Entries in GOC DB starting since the last report.
|
| Service
|
Scheduled?
|
Outage/At Risk
|
Start
|
End
|
Duration
|
Reason
|
| Whole Site
|
UNSCHEDULED
|
WARNING
|
29/03/2016 21:50
|
30/03/2016 11:00
|
13 hours and 10 minutes
|
Network problem fixed. Site contactable and services now available. Putting site in warning overnight.
|
| Whole site
|
UNSCHEDULED
|
OUTAGE
|
29/03/2016 19:00
|
29/03/2016 21:46
|
2 hours and 46 minutes
|
Network problem casuing site to be unavailable. Cause as yet unknown.
|
| Open GGUS Tickets (Snapshot during morning of meeting)
|
| GGUS ID |
Level |
Urgency |
State |
Creation |
Last Update |
VO |
Subject
|
| 120350
|
Green
|
Less Urgent
|
In Progress
|
2016-03-22
|
2016-03-22
|
LSST
|
Enable LSST at RAL
|
| 119841
|
Green
|
Less Urgent
|
In Progress
|
2016-03-01
|
2016-03-22
|
LHCb
|
HTTP support for lcgcadm04.gridpp.rl.ac.uk
|
| 117683
|
Green
|
Less Urgent
|
In Progress
|
2015-11-18
|
2016-02-17
|
|
CASTOR at RAL not publishing GLUE 2
|
Key: Atlas HC = Atlas HammerCloud (Queue ANALY_RAL_SL6, Template 508); CMS HC = CMS HammerCloud
| Day |
OPS |
Alice |
Atlas |
CMS |
LHCb |
Atlas HC |
CMS HC |
Comment
|
| 23/03/16 |
100 |
100 |
100 |
100 |
100 |
98 |
100 |
|
| 24/03/16 |
100 |
100 |
100 |
85 |
92 |
94 |
100 |
Network problem (Partial failure of one of four links to UKLight router).
|
| 25/03/16 |
100 |
100 |
61 |
49 |
88 |
N/A |
100 |
Continuation of above.
|
| 26/03/16 |
100 |
100 |
100 |
100 |
96 |
N/A |
N/A |
Single SRM Test failure. [SRM_INVALID_PATH] No such file or directory
|
| 27/03/16 |
100 |
100 |
66 |
55 |
100 |
N/A |
100 |
Problem with test submission affecting many Atlas & CMS sites.
|
| 28/03/16 |
100 |
100 |
100 |
100 |
100 |
N/A |
100 |
|
| 29/03/16 |
89.6 |
100 |
100 |
85 |
90 |
N/A |
90 |
Network problem. (Problem with one of RAL border routers. Tier1 Router pair didn't fail over).
|
