RAL Tier1 Operations Report for 17th February 2016
| Review of Issues during the week 10th to 17th February 2016.
|
- On Wednesday afternoon (27th Jan) one of the Windows hypervisors crashed. This was a local storage node - with no failover to other hypervisors. A number of services were unavailable or degraded during the afternoon and an outage for those affected services in the GOC DB was declared.
- The OPN link to CERN has been very busy during this last fortnight.
- We have had a lot of failures of the Atlas HammerCloud Tests and running Atlas analysis jobs. Initially this was thought to be due to a missing disk server (GDSS677). However, it subsequently became clear that the cause was the CVMFS inode count on the Worker Nodes exceeding 2**32. This is a problem that we had seen some months ago.
- During last week we had a problem with a particular Atlas Tape. We were unable to read most of the files off the tape. We have declared 5898 files lost from this tape. This was a T10KC tape and it is being sent off for analysis to see if we can understand what happened.
| Resolved Disk Server Issues
|
- GDSS620 (GenTape - D0T1) failed on the first January. The server was returned to service on 1st February. This server had failed on repeat occasions before. Two disks were replaced in the server.
- GDSS682 (AtlasDataDisk - D1T0) failed on Sunday evening (31st Jan). It was returned to service at the end of the afternoon the following day although investigations had failed to find a cause. There was one corrupt file found on gdss682 when it returned to production. This file was declared lost to Atlas.
- GDSS667 (AtlasScratchDisk - D1T0) Failed on Monday 18th Jan with a read-only file system. On investigation three disks in the RAID set had problems. Following a lot of work a small number of files were recovered from the server. However, the large majority of the files were declared lost to Atlas. The server re-ran the acceptance tests before being put back into service on Friday 5th Feb. As reported a fortnight ago most of the files on this server were reported lost to Atlas.
- GDSS744 (AtlasDataDisk - D1T0) failed on Sunday evening (7th Feb). A RAID consistency check threw out a bad drive. Following the replacement of that drive the server was returned to service yesterday afternoon (9th Feb). It is initially in read-only mode - and will be put back in read/write once the RAID consistency check has been re-run.
- GDSS706 (AtlasDataDisk - D1T0) was taken out of service for a couple of yours yesterday (9th Feb) for the battery on the RAID card to be replaced.
| 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.
| Ongoing Disk Server Issues
|
| Notable Changes made since the last meeting.
|
- ARC-CE02,3 & 4 have been upgraded to version 5.0.5. (ARC-CE01 was done last week).
- Batches of worker nodes are being drained to reset the CVMFS inodes count.
- Condor is being updated (to version 8.4.4) on a couple of batches of worker nodes. (These nodes are being drained and rebooted - which also resolves the CVMFS inodes problem on them).
| Advanced warning for other interventions
|
| The following items are being discussed and are still to be formally scheduled and announced.
|
- Update the repack Castor repack instance from version 2.1.14.13 to 2.1.14.15. (Proposed for 10/2/16)
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.
|
| Open GGUS Tickets (Snapshot during morning of meeting)
|
| GGUS ID |
Level |
Urgency |
State |
Creation |
Last Update |
VO |
Subject
|
| 119456
|
Green
|
Urgent
|
In Progress
|
2016-02-10
|
2016-02-10
|
CMS
|
File waiting for staging
|
| 119450
|
Green
|
Less Urgent
|
In Progress
|
2016-02-09
|
2016-02-09
|
Atlas
|
RAL_LCG2: SOURCE SRM_GET_TURL error on the turl request
|
| 119389
|
Green
|
Urgent
|
In Progress
|
2016-02-05
|
2016-02-05
|
LHCb
|
Data transfer problem to RAL BUFFER
|
| 118809
|
Green
|
Urgent
|
On Hold
|
2016-01-05
|
2016-01-13
|
|
Towards a recommendation on how to configure memory limits for batch jobs
|
| 117683
|
Green
|
Less Urgent
|
In Progress
|
2015-11-18
|
2016-01-05
|
|
CASTOR at RAL not publishing GLUE 2
|
| 116864
|
Red
|
Urgent
|
In Progress
|
2015-10-12
|
2016-01-29
|
CMS
|
T1_UK_RAL AAA opening and reading test failing again...
|
| 109358
|
Green
|
Less Urgent
|
Waiting Reply
|
2015-02-05
|
2016-02-09
|
SNO+
|
RAL WMS unavailable
|
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
|
| 10/02/16 |
100 |
100 |
100 |
100 |
100 |
97 |
100 |
|
| 11/02/16 |
100 |
100 |
100 |
100 |
100 |
100 |
N/A |
|
| 12/02/16 |
100 |
100 |
100 |
100 |
100 |
94 |
100 |
|
| 13/02/16 |
100 |
100 |
100 |
100 |
100 |
100 |
N/A |
|
| 14/02/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 15/02/16 |
100 |
100 |
97 |
100 |
100 |
93 |
100 |
Single SRM Test failure on Put (could not open connection to srm-atlas.gridpp.rl.ac.uk)
|
| 16/02/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
