RAL Tier1 Operations Report for 25th November 2015
| Review of Issues during the week 18th to 25th November 2015.
|
| Resolved Disk Server Issues
|
- GDSS707 (AtlasDataDisk - D1T0) was returned to services yesterday afternoon (24th Nov.). It had been out of production since Friday (16th Oct). The server was drained, the CPU swapped, and the server put through a week long re-acceptance test before being returned to service.
- GDSS720 (AtlasDataDisk - D1T0) was returned to services yesterday afternoon (24th Nov.). It had failed on 9th Nov. The server was drained, the CPU swapped, and the server put through a week long re-acceptance test before being returned to service.
- GDSS678 (CMSTape - D0T1) failed on Saturday evening (21st Nov). The server was returned to production yesterday afternoon (24th Nov). A disk had been replaced and the rebuild completed before returning to service. Two files were declared lost to CMS - both of which were being written at the time the server failed.
| 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.
- 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.
|
| Advanced warning for other interventions
|
| The following items are being discussed and are still to be formally scheduled and announced.
|
- Upgrade of remaining Castor disk servers (those in tape-backed service classes) to SL6. This will be transparent to users.
- Some detailed internal network re-configurations to enable the removal of the old 'core' switch from our network. This includes changing the way the UKLIGHT router connects into the Tier1 network. As part of this we plan to increase the bandwidth available on the bypass route from 10 to 20Gbit.
- Implementing a changed algorithm for the draining of worker nodes to make space for multi-core jobs. The new version allow "pre-emptable" jobs to run in the job slots until they are needed.
Listing by category:
- Databases:
- Switch LFC/3D to new Database Infrastructure.
- Castor:
- Update SRMs to new version (includes updating to SL6).
- Update disk servers to SL6 (ongoing)
- Update to Castor version 2.1.15.
- Networking:
- Complete changes needed to remove the old core switch from the Tier1 network.
- Make routing changes to allow the removal of the UKLight Router.
- 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
|
| 117846
|
Green
|
Urgent
|
In Progress
|
2015-11-23
|
2015-11-24
|
Atlas
|
ATLAS request- storage consistency checks
|
| 117683
|
Green
|
Less Urgent
|
In Progress
|
2015-11-18
|
2015-11-19
|
|
CASTOR at RAL not publishing GLUE 2
|
| 116866
|
Yellow
|
Less Urgent
|
In Progress
|
2015-10-12
|
2015-10-19
|
SNO+
|
snoplus support at RAL-LCG2 (pilot role)
|
| 116864
|
Yellow
|
Urgent
|
In Progress
|
2015-10-12
|
2015-11-12
|
CMS
|
T1_UK_RAL AAA opening and reading test failing again...
|
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
|
| 18/11/15 |
100 |
100 |
100 |
100 |
96 |
100 |
100 |
Single SRM test failure on listing "[SRM_INVALID_PATH] No such file or directory"
|
| 19/11/15 |
100 |
100 |
100 |
100 |
100 |
100 |
N/A |
|
| 20/11/15 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 21/11/15 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 22/11/15 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 23/11/15 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 24/11/15 |
100 |
100 |
100 |
96 |
100 |
97 |
100 |
Single SRM Test failure on PUT. Monitoring problem - couldn't find file to copy in.
|
