RAL Tier1 Operations Report for 1st July 2015
Review of Issues during the week 24th June to 1st July 2015.
|
- As reported at the last meeting. AtlasDataDisk in Castor became full on the morning of Wed 17th June. Four additional disk servers were added on Wednesday afternoon (17th) and a further four on Friday (19th). Note that one of the initial set of four servers (GDSS763) failed on the Friday (19th).
- During last week LHCb reported problems accessing old files in Castor which did not have a stored checksum. (These files have been like this for some years). Stored checksums have been retrospectively added to Castor for these cases.
- Last Wednesday (17th) following a problem flagged up by LHCb it was realized that we were using incorrect VOMS servers for regenerating the Castor gridmap files. This was fixed that day.
- A problem transferring files from FNAL to us is being investigated.
- Yesterday, Tuesday 23rd June, There were two network issues. The first was a spontaneous reboot of a core network switch that led to a break in connectivity to the Tier1 for around 8 minutes. The second was a very high rate of traffic around the Tier1 network that lasted for around 45 minutes from 16:00. This is not completely understood, but appears to have been caused by restarting an old hypervisor and this causing more than one copy of a particular Virtual Machine to run.
Resolved Disk Server Issues
|
- The draining of GDSS763 (AtlasDataDisk - D1T0) has been complerted and the server removed. This server failed on the 19th June. Following further crashes the disks were placed in a different server/chassis so that all files could be drained off.
Current operational status and issues
|
- We are running with a single router connecting the Tier1 network to the site network, rather than a resilient pair.
- The post mortem review of the network incident on the 8th April is being finalised.
- The intermittent, low-level, load-related packet loss over the OPN to CERN is still being tracked.
Ongoing Disk Server Issues
|
Notable Changes made since the last meeting.
|
- On Wednesday (just after last week's meeting) a network test was carried out. Thi confirmed that non-Tier1 services on our network now route traffic avoiding our (problematic) Tier1 router pair. The test also coinfirmed the long-standing problem in the primary Tier1 router. This test paves the way for a longer intervention, with the vendor present, to try and get to the bottom of the router problem.
- Old files in Castor that were missing stored checksums have had these added.
- Eight additional disk servers have been added to AtlasDataDisk (approaching a Petabyte of extra capacity).
- The batch job limit for Alice has been completely removed. (It was set at 6000).
- A detailed change to a database procedure has been made to the LHCb Castor stager (yesterday - Tuesday 23rd) and then to CMS today (Wed 24th). This change significantly speeds up file open times within Castor.
- Files are being successfull transferred from Durham for Dirac.
Service
|
Scheduled?
|
Outage/At Risk
|
Start
|
End
|
Duration
|
Reason
|
Whole site
|
SCHEDULED
|
WARNING
|
01/07/2015 10:00
|
01/07/2015 11:30
|
1 hour and 30 minutes
|
Warning on site during quarterly UPS/Generator load test.
|
arc-ce05.gridpp.rl.ac.uk
|
SCHEDULED
|
OUTAGE
|
10/06/2015 12:00
|
08/07/2015 12:00
|
28 days,
|
This particular ARC CE will be decommisioned. (Four other ARC CEs remain in production).
|
Advanced warning for other interventions
|
The following items are being discussed and are still to be formally scheduled and announced.
|
Listing by category:
- Databases:
- Switch LFC/3D to new Database Infrastructure.
- Update to Oracle 11.2.0.4. This will affect all services that use Oracle databases: Castor, Atlas Frontier (LFC done)
- Castor:
- Update SRMs to new version (includes updating to SL6).
- Update the Oracle databses behind Castor to version 11.2.0.4. Will require some downtimes (See above)
- Update disk servers to SL6.
- Update to Castor version 2.1.15.
- Networking:
- Resolve problems with primary Tier1 Router. Need to schedule a roughly half-day outage for the vendor to carry out investigations.
- Enable the RIP protocol for updating routing tables on the Tier1 routers. (Install patch to Router software).
- Increase bandwidth of the link from the Tier1 into the RAL internal site network to 40Gbit.
- Make routing changes to allow the removal of the UKLight Router.
- Cabling/switch changes to the network in the UPS room to improve resilience.
- Fabric
- Firmware updates on remaining EMC disk arrays (Castor, FTS/LFC)
Entries in GOC DB starting since the last report.
|
Service
|
Scheduled?
|
Outage/At Risk
|
Start
|
End
|
Duration
|
Reason
|
Whole site
|
SCHEDULED
|
WARNING
|
01/07/2015 10:00
|
01/07/2015 11:30
|
1 hour and 30 minutes
|
Warning on site during quarterly UPS/Generator load test.
|
arc-ce05.gridpp.rl.ac.uk
|
SCHEDULED
|
OUTAGE
|
10/06/2015 12:00
|
08/07/2015 12:00
|
28 days,
|
This particular ARC CE will be decommisioned. (Four other ARC CEs remain in production).
|
Open GGUS Tickets (Snapshot during morning of meeting)
|
GGUS ID |
Level |
Urgency |
State |
Creation |
Last Update |
VO |
Subject
|
114512
|
Green
|
Less Urgent
|
In Progress
|
2015-06-12
|
2015-06-22
|
Atlas
|
deletion errors for RAL-LCG2
|
113910
|
Green
|
Less Urgent
|
Waiting Reply
|
2015-05-26
|
2015-06-23
|
SNO+
|
RAL data staging
|
113836
|
Green
|
Less Urgent
|
In Progress
|
2015-05-20
|
2015-06-24
|
|
GLUE 1 vs GLUE 2 mismatch in published queues
|
112721
|
Red
|
Less Urgent
|
In Progress
|
2015-03-28
|
2015-06-23
|
Atlas
|
RAL-LCG2: SOURCE Failed to get source file size
|
109694
|
Red
|
Urgent
|
Waiting Reply
|
2014-11-03
|
2015-06-23
|
SNO+
|
gfal-copy failing for files at RAL
|
108944
|
Red
|
Less Urgent
|
In Progress
|
2014-10-01
|
2015-06-16
|
CMS
|
AAA access test failing at T1_UK_RAL
|
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
|
24/06/15 |
100 |
100 |
100 |
100 |
100 |
100 |
99 |
|
25/06/15 |
100 |
100 |
100 |
100 |
100 |
97 |
99 |
|
26/06/15 |
100 |
100 |
100 |
100 |
100 |
100 |
100 |
|
27/06/15 |
100 |
100 |
100 |
100 |
100 |
98 |
n/a |
|
28/06/15 |
100 |
100 |
100 |
100 |
100 |
98 |
100 |
|
29/06/15 |
100 |
100 |
100 |
100 |
100 |
98 |
100 |
|
30/06/15 |
54.9 |
100 |
100 |
100 |
100 |
85 |
100 |
|