RAL Tier1 Operations Report for 25th November 2015
Review of Issues during the week 18th to 25th November 2015.
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Resolved Disk Server Issues
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- 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
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- 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
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None
Notable Changes made since the last meeting.
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Advanced warning for other interventions
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The following items are being discussed and are still to be formally scheduled and announced.
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- 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.
- 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.
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None
Open GGUS Tickets (Snapshot during morning of meeting)
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GGUS ID |
Level |
Urgency |
State |
Creation |
Last Update |
VO |
Subject
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117846
|
Green
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Urgent
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In Progress
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2015-11-23
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2015-11-24
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Atlas
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ATLAS request- storage consistency checks
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117683
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Green
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Less Urgent
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In Progress
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2015-11-18
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2015-11-19
|
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CASTOR at RAL not publishing GLUE 2
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116866
|
Yellow
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Less Urgent
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In Progress
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2015-10-12
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2015-10-19
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SNO+
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snoplus support at RAL-LCG2 (pilot role)
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116864
|
Yellow
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Urgent
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In Progress
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2015-10-12
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2015-11-12
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CMS
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T1_UK_RAL AAA opening and reading test failing again...
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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
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18/11/15 |
100 |
100 |
100 |
100 |
96 |
100 |
100 |
Single SRM test failure on listing "[SRM_INVALID_PATH] No such file or directory"
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19/11/15 |
100 |
100 |
100 |
100 |
100 |
100 |
N/A |
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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 |
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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.
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