RAL Tier1 Operations Report for 8th February 2017
Review of Issues during the fortnight 25th January to 8th February 2017.
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- We have still been seeing SAM SRM tests failures for CMS. These are owing to the total load on the instance. (Now recorded as an ongoing operational problem below).
- There was a performance problem on the LHCb Castor instance following the upgrade last Wednesday. This was resolved by the end of the following day.
- On Monday the LHCb Castor instance was stopped while OS security patches were applied and nodes rebooted. It took a couple of hours after the planned intervention to get the last disk server back as a couple of them had problems on reboot.
Resolved Disk Server Issues
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- GDSS780 (LHCbDst - D1T0) crashed on 25th Jan. It was returned to service later that day after a memory swap-around.
- GDSS687 (AtlasDataDisk - D1T0) was removed from production on 27th January when it was found to have two faulty disk drives. It was returned to service on the 30th after the drive replacements.
- GDSS776 (LHCbDst - D1T0) crashed on 3rd Feb. It was returned to service on the evening of the same day after being checked. Five files were lost from the time of the crash.
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.
- We are seeing a rate of failures of the CMS SAM tests against the SRM. These are affecting our (CMS) availabilities. We attribute these failures to load on Castor.
Ongoing Disk Server Issues
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Notable Changes made since the last meeting.
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- Castor 2.1.15 updates carried out on the LHCb and Atlas stagers.
- The top BDIIs have been put behind load balancers. (This was recently done for the site BDIIs)
- Migration of LHCb data from 'C' to 'D' tapes ongoing. Now over 90% done with less than 100 out of the 1000 tapes still to do.
- A resiliency test was carried out on ECHO (CEPH) - checking its ability to handle failures of a rack of equipment etc. The system passed this successfully. An internal data migration test within ECHO is now underway. This has had some impact on external access.
Service
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Scheduled?
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Outage/At Risk
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Start
|
End
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Duration
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Reason
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Whole site
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SCHEDULED
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WARNING
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01/03/2017 07:00
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01/03/2017 11:00
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4 hours
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Warning on site during network intervention in preparation for IPv6.
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All Castor and ECHO storage and Perfsonar.
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SCHEDULED
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WARNING
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22/02/2017 07:00
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22/02/2017 11:00
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4 hours
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Warning on Storage and Perfsonar during network intervention in preparation for IPv6.
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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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Pending - but not yet formally announced:
- Merge AtlasScratchDisk into larger Atlas disk pool.
Listing by category:
- Castor:
- Update SRMs to new version, including updating to SL6. This will be done after the Castor 2.1.15 update.
- Networking:
- Enabling IPv6 onto production network.
Entries in GOC DB starting since the last report.
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Service
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Scheduled?
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Outage/At Risk
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Start
|
End
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Duration
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Reason
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IPv6 testbed nodes
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UNSCHEDULED
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OUTAGE
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01/02/2017 07:30
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01/02/2017 12:00
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4 hours and 30 minutes
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RAL IPv6 testbed network intervention
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srm-cms-disk.gridpp.rl.ac.uk, srm-cms.gridpp.rl.ac.uk,
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SCHEDULED
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OUTAGE
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31/01/2017 10:00
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31/01/2017 11:46
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1 hour and 46 minutes
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Castor 2.1.15 Upgrade. Only affecting CMS instance. (CMS stager component being upgraded).
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srm-alice.gridpp.rl.ac.uk,
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UNSCHEDULED
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OUTAGE
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27/01/2017 16:00
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30/01/2017 14:00
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2 days, 22 hours
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Continuing problems with Alice SRM xrootd access
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srm-alice.gridpp.rl.ac.uk,
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UNSCHEDULED
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OUTAGE
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27/01/2017 12:00
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27/01/2017 16:00
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4 hours
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Continuing problems with Alice SRM xrootd access
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srm-alice.gridpp.rl.ac.uk,
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UNSCHEDULED
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OUTAGE
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26/01/2017 16:00
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27/01/2017 12:00
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20 hours
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Problems for alice storage after Castor upgrade at RAL
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Castor GEN instance
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SCHEDULED
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OUTAGE
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26/01/2017 10:00
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26/01/2017 16:00
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6 hours
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Castor 2.1.15 Upgrade. Only affecting GEN instance. (GEN stager component being upgraded).
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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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126376
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Green
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Urgent
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In Progress
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2017-02-05
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2017-02-08
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CMS
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SAM3 CE & SRM test failures at T1_UK_RAL
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126296
|
Green
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Urgent
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Waiting Reply
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2017-02-01
|
2017-02-06
|
CMS
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SAM SRM test errors at T1_UK_RAL
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126184
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Green
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Less Urgent
|
In Progress
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2017-01-26
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2017-02-07
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Atlas
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Request of inputs for new sites monitoring
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124876
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Red
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Less Urgent
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On Hold
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2016-11-07
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2017-01-01
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OPS
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[Rod Dashboard] Issue detected : hr.srce.GridFTP-Transfer-ops@gridftp.echo.stfc.ac.uk
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117683
|
Red
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Less Urgent
|
On Hold
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2015-11-18
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2016-12-07
|
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CASTOR at RAL not publishing GLUE 2. We looked at this as planned in December (report).
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Key: Atlas HC = Atlas HammerCloud (Queue ANALY_RAL_SL6, Template 844); CMS HC = CMS HammerCloud
Day |
OPS |
Alice |
Atlas |
CMS |
LHCb |
Atlas HC |
CMS HC |
Comment
|
25/01/17 |
100 |
100 |
100 |
100 |
100 |
99 |
100 |
|
26/01/17 |
-1 |
63 |
92 |
100 |
100 |
100 |
100 |
ALICE: GEN Castor stager 2.1.15 upgrade; Atlas: Checks timed out.
|
27/01/17 |
100 |
0 |
100 |
100 |
100 |
100 |
100 |
Alice specific problems after the Castor GEN upgrade.
|
28/01/17 |
100 |
0 |
100 |
100 |
100 |
100 |
100 |
Alice specific problems after the Castor GEN upgrade.
|
29/01/17 |
100 |
0 |
100 |
100 |
100 |
98 |
98 |
Alice specific problems after the Castor GEN upgrade.
|
30/01/17 |
100 |
32 |
86 |
100 |
100 |
90 |
100 |
Atlas: Could not open connection to srm-atlas.gridpp.rl.ac.uk; Alice specific problems after the Castor GEN upgrade.
|
31/01/17 |
-1 |
100 |
100 |
100 |
100 |
89 |
100 |
|
01/02/17 |
100 |
100 |
100 |
100 |
85 |
100 |
N/A |
SRM test failures to list file.
|
02/02/17 |
100 |
100 |
100 |
100 |
100 |
100 |
97 |
|
03/02/17 |
100 |
100 |
100 |
100 |
96 |
98 |
100 |
SRM test failures to list file.
|
04/02/17 |
100 |
100 |
98 |
100 |
100 |
100 |
100 |
Could not open connection to srm-atlas.gridpp.rl.ac.uk
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05/02/17 |
100 |
100 |
90 |
100 |
100 |
100 |
100 |
Checks timed out.
|
06/02/17 |
100 |
100 |
85 |
100 |
100 |
99 |
100 |
Checks timed out.
|
07/02/17 |
100 |
100 |
100 |
100 |
100 |
99 |
100 |
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- More detail was given on the problems encountered by the LHCb Castor instance after the stager update. These were a version of a particular library used by Castor needed updating, a Castor parameter and a database parameter was also adjusted.
- There will need to be an update to all Oracle database servers to remove a component called ASMLIB. This si being tested now.
- Some ALICE problems were reported last week and a cap put on the number of batch jobs they can run. This cap has since been removed and no further problems encountered. (At the peak ALICE were running around 10,000 jobs on our batch farm yesterday. Capacity being available as Atlas were not running during the Atlas Castor update).