RAL Tier1 Operations Report for 20th April 2016
| Review of Issues during the week 13th to 20th April 2016.
|
- There was a problem with the RAL core network that started late evening Friday 15th April and continued until the Saturday afternoon. We experienced four significant breaks in connectivity during this period. A fifteen hour outage has been declared in the GOC DB. During the time this was ongoing our Tier1 routers flipped between themselves a number of times.
| Resolved Disk Server Issues
|
- GDSS771 (LHCbDst - D1T0) crashed on Saturday (9th April). It has been completely drained of files and is out of production for further investigation.
- GDSS731 (LHCbDst - D1T0) crshed early evening Friday 15th April. Following investigation it was returned to service read-only the following day.
| 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.
- The draining of Castor disk servers for Atlas is very slow. We need to drain a few old servers to provide spares - this being part of the deployment plan and server lifecycle. This does not yet impact services but is being followed up.
| Ongoing Disk Server Issues
|
- GDSS619 (GenTape - D0T1) failed on Friday (15th April). It is under investigation.
- GDSS620 (GenTape - D0T1) was reporting problems and was taken out of production during yesterday (19th April).
- GDSS635 (AtlasTape - D0T1) crashed on the 6th April. It was returned to service on Tuesday (19th April) with eight files having been declared lost to Atlas. However, the server failed again in the early hours of this morning.
- GDSS634 (AtlasTape - D0T1) failed this morning. Work is ongoing.
| Notable Changes made since the last meeting.
|
- Atlas have been switched to writing new data to the T10KD drives.
- The HAProxy load balancer is now handling some 60% of the requests to the Test FTS3 instance.
None
| Advanced warning for other interventions
|
| The following items are being discussed and are still to be formally scheduled and announced.
|
- The Castor 2.1.15 update is pending. Testing has shown a database related performance issue which is being followed up. We await successful resolution of that problem and completion of testing before scheduling. Following advice from the developers we will not upgrade the SRMs before the Castor 2.1.15 upgrade.
- Decommissioning of "GEN Scratch" storage in Castor. (Formally announced by EGI broadcast).
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
- Once the use of the Load Balancer (HAProxy) has been proven for the test FTS service it will be extended to other services.
| Entries in GOC DB starting since the last report.
|
| Service
|
Scheduled?
|
Outage/At Risk
|
Start
|
End
|
Duration
|
Reason
|
| Whole Site
|
UNSCHEDULED
|
OUTAGE
|
15/04/2016 23:40
|
16/04/2016 14:40
|
15 hours
|
Network problems at RAL Tier1 resulting in four hour long network breaks to the entire site
|
| Open GGUS Tickets (Snapshot during morning of meeting)
|
| GGUS ID |
Level |
Urgency |
State |
Creation |
Last Update |
VO |
Subject
|
| 120920
|
Green
|
Less Urgent
|
Waiting Reply
|
2016-04-19
|
2016-04-19
|
SNO+
|
XRootD issues at RAL
|
| 120810
|
Green
|
Urgent
|
Waiting Reply
|
2016-04-13
|
2016-04-19
|
Biomed
|
Decommissioning of SE srm-biomed.gridpp.rl.ac.uk - forbid write access for biomed users
|
| 120624
|
Green
|
Urgent
|
Waiting Reply
|
2016-04-05
|
2016-04-18
|
CMS
|
Consistency Check for T1_UK_RAL
|
| 120350
|
Green
|
Less Urgent
|
In Progress
|
2016-03-22
|
2016-04-05
|
LSST
|
Enable LSST at RAL
|
| 119841
|
Yellow
|
Less Urgent
|
In Progress
|
2016-03-01
|
2016-03-22
|
LHCb
|
HTTP support for lcgcadm04.gridpp.rl.ac.uk
|
| 117683
|
Green
|
Less Urgent
|
On Hold
|
2015-11-18
|
2016-04-05
|
|
CASTOR at RAL not publishing GLUE 2
|
Key: Atlas HC = Atlas HammerCloud (Queue ANALY_RAL_SL6, Template 729); CMS HC = CMS HammerCloud
| Day |
OPS |
Alice |
Atlas |
CMS |
LHCb |
Atlas HC |
CMS HC |
Comment
|
| 13/04/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 14/04/16 |
100 |
100 |
100 |
100 |
100 |
100 |
N/A |
|
| 15/04/16 |
97.2 |
98 |
100 |
96 |
99 |
97 |
99 |
Site networking problem.
|
| 16/04/16 |
79.2 |
84 |
92 |
75 |
70 |
84 |
90 |
Site networking problem - continued.
|
| 17/04/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 18/04/16 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
| 19/04/16 |
100 |
100 |
100 |
100 |
100 |
100 |
N/A |
|
