RAL Tier1 Operations Report for 7th June 2017
| Review of Issues during the week 24th to 31st May 2017.
|
- A problem of ARP poisoning on the Tier1 network is affecting some monitoring used by Echo. The cause of this is now believed to be understood and the fix (a setting change in the OPN Router) has been applied.
- There is a problem on the site firewall which is causing problems for some specific data flows. This was being investigated in connection with videoconferencing problems. It is expected that this is having an effect on our data that flows through the firewall (such as to/from worker nodes).
- Atlas carried out a large deletion test of files in Echo last week. Overall the results were pleasing with the bulk of the files deleted successfully and in a reasonable timescale. However, some (one to two thousand) files failed to delete. Most of these were cleaned up manually leaving a handful for debugging purposes. However, the system subsequently also deleted these remaining files without manual intervention.
| Resolved Disk Server Issues
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- GDSS658 (AtlasScratchDisk - D1T0) crashed last Tuesday (30th May). It was returned to service on Thursday (1st Jue). Two disks were replaced as the testing flushed these out as problematic.
| Current operational status and issues
|
- We are still seeing a rate of failures of the CMS SAM tests against the SRM. These are affecting our (CMS) availabilities. CMS are also looking at file access performance and have turned off "lazy-download". The CMS SRM SAM test success rate has improved since the Castor 2.1.16 upgrade on the 25th May, although is still not 100%. It is still planned to re-visit this issue now Castor has been upgraded.
- LHCb Castor performance has been OK since the 2.1.16 update although this was not under and high load. A load test (mimicking the stripping/merging campaign) was carried out last Wednesday (24th May). This was successful in that the specific performance/timeout problem seen before the Castor 2.1.16 upgrade was not seen. The main limitation encountered within Castor was load on the older disk servers in the instance. Following the 2.1.16 upgrade and this (successful) test this item is being removed from the list of ongoing issues.
| Ongoing Disk Server Issues
|
- GDSS793 (AtlasDataDisk - D1T0) was taken out of service yesterday as two disk drives in the server were faulty. Work is ongoing on this srever.
| Limits on concurrent batch system jobs.
|
| Notable Changes made since the last meeting.
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- CMS Castor and GEN instances updated to Castor version 2.1.16-13 and the associated SRMs also upgraded to version 2.1.16.
- For LHCb Castor the xroot manager was installed on the (LHCb) stager. This resolves a problem introduced by version 2.1.16 (and reported last week) that affected LHCb where a TURL returned by the SRM did not always work when used for xroot access owing to an incorrect hostname.
- CEs being migrated to use the load balancers in front of the argus service.
- Batch access has been enabled for LIGO and the MICE pilot role.
- Parameter change in the OPN Router to stop it providing proxy ARP information.
| Advanced warning for other interventions
|
| 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:
- Increase OPN link to CERN from 2*10Gbit to 3*10Gbit links.
Listing by category:
- Castor:
- Move to generic Castor headnodes.
- Merge AtlasScratchDisk into larger Atlas disk pool.
- Networking
- Increase OPN link to CERN from 2*10Gbit to 3*10Gbit links.
- Enable first services on production network with IPv6 now that the addressing scheme has been agreed. (Perfsonar already working over IPv6).
- Services
- Put argus systems behind a load balancers to improve resilience.
- The production FTS needs updating. This will no longer support the soap interface. (The "test" FTS , used by Atlas, has already been upgraded.)
| Entries in GOC DB starting since the last report.
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| Service
|
Scheduled?
|
Outage/At Risk
|
Start
|
End
|
Duration
|
Reason
|
| Castor GEN instace (srm-alice, srm-biomed, srm-dteam, srm-ilc, srm-mice, srm-na62, srm-pheno, srm-snoplus, srm-t2k)
|
SCHEDULED
|
OUTAGE
|
31/05/2017 10:00
|
31/05/2017 12:56
|
5 hours
|
Upgrade of Castor GEN instance to version 2.1.16.
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| Open GGUS Tickets (Snapshot during morning of meeting)
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- GGUS system currently not available. No report on open GGUS tickets. (GGUS service was back at the end of the morning).
Key: Atlas HC = Atlas HammerCloud (Queue ANALY_RAL_SL6, Template 845); Atlas HC Echo = Atlas Echo (Template 841);CMS HC = CMS HammerCloud
| Day |
OPS |
Alice |
Atlas |
CMS |
LHCb |
Atlas Echo |
Atlas HC |
Atlas HC Echo |
CMS HC |
Comment
|
| 24/05/17 |
100 |
100 |
100 |
97 |
100 |
100 |
99 |
99 |
100 |
SRM Test failures (user timeout)
|
| 25/05/17 |
100 |
100 |
100 |
87 |
100 |
100 |
100 |
100 |
98 |
SRM Test failures (user timeout)
|
| 26/05/17 |
100 |
100 |
98 |
98 |
100 |
100 |
100 |
100 |
100 |
SRM Test failures: Atlas: One error ‘User belonging to VO not authorized to access space token ATLASDATADISK; CMS: user timeout.
|
| 27/05/17 |
100 |
100 |
100 |
98 |
100 |
100 |
100 |
100 |
100 |
SRM Test failures (user timeout)
|
| 28/05/17 |
100 |
100 |
100 |
97 |
100 |
100 |
100 |
100 |
100 |
SRM Test failures (user timeout)
|
| 29/05/17 |
100 |
100 |
100 |
98 |
100 |
100 |
98 |
100 |
100 |
SRM Test failures (user timeout)
|
| 30/05/17 |
100 |
100 |
100 |
94 |
100 |
100 |
92 |
100 |
100 |
SRM Test failures (user timeout)
|
| 31/05/17 |
100 |
100 |
100 |
89 |
100 |
100 |
100 |
100 |
100 |
CMS: Some ‘User timeout over’ on the SRM tests. There were a few CE test failures too, with ‘Job held’ and ‘unable to open remote xrootd ..’ errors.
|
| 01/06/17 |
100 |
100 |
100 |
97 |
100 |
100 |
100 |
100 |
100 |
CMS: Some SRM failures with an error of ‘ERROR: DESTINATION SRM_PUT_TURL error on the turl request : [SE][StatusOfPutRequest][SRM_FAILURE] Unable to issue PrepareToPut request to Castor’.
|
| 02/06/17 |
100 |
100 |
100 |
92 |
100 |
100 |
100 |
100 |
100 |
CMS: Some instances of “Unable to issue PrepareToPut request to Castor”
|
| 03/06/17 |
100 |
100 |
100 |
90 |
100 |
100 |
100 |
100 |
100 |
CMS: Some user timeout errors on SRM tests.
|
| 04/06/17 |
100 |
100 |
100 |
97 |
100 |
100 |
100 |
100 |
100 |
CMS: Some user timeout errors on SRM tests.
|
| 05/06/17 |
100 |
100 |
100 |
94 |
100 |
100 |
100 |
100 |
100 |
CMS: SRM test failures. “User timeout” – some on Put, some on Get.
|
| 06/06/17 |
100 |
100 |
100 |
92 |
100 |
100 |
100 |
100 |
100 |
CMS: SRM test failures. “User timeout” – some on Put, some on Get.
|
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