Difference between revisions of "Tier1 Operations Report 2015-11-04"

Revision as of 10:30, 4 November 2015

Review of Issues during the week 28th October to 4th November 2015.

Early on Saturday (24/10/2015) morning, arc-ce02 developed problems. It was probably due to problems with the underlying hyper-visor. Some other less critical machines on the same hyper-visor were also affected.
On Monday (26/10/2015) evening, there were problems with the WMS servers. A user was submitting jobs with very big output files. This was filling up the working partition on the machines.

Resolved Disk Server Issues

gdss665 (AtlasTape - D0T1) failed on Sat (24th Oct). Following a disk replacement and updating the firmware in the disk controller the system was re-run through the acceptance testing for 5 days before being returned to service yesterday (3rd November).
gdss663 (AtlasTape - D0T1) failed on Sun (25th Oct). Following a disk and battery replacement and updating the firmware in the disk controller the system was re-run through the acceptance testing for 5 days before being returned to service yesterday (3rd November).

Current operational status and issues

The LHCb problem with 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.
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.
Long-standing CMS issues. The two items that remain are CMS Xroot (AAA) redirection and file open times. Work is ongoing into the Xroot redirection with a new server having been added in recent weeks. File open times using Xroot remain slow but this is a less significant problem.

Ongoing Disk Server Issues

gdss707 (AtlasDataDisk - D1T0) has been out of production since Friday (16th Oct). The server is currently undergoing testing with fabric.

gdss664 (AtlasTape - D0T1) has had a few issues starting over the weekend. This morning (28th Oct) we decided to remove it from production so it can be investigated.

Notable Changes made since the last meeting.

Declared in the GOC DB

Advanced warning for other interventions

The following items are being discussed and are still to be formally scheduled and announced.

Upgrade of remaining Castor disk servers (those in tape-backed service classes) to SL6. This will be transparent to users.
Some detailed internal network re-configurations to enable the removal of the old 'core' switch from our network. This includes changing the way the UKLIGHT router connects into the Tier1 network.

Listing by category:

Databases:
- Switch LFC/3D to new Database Infrastructure.
Castor:
- Update SRMs to new version (includes updating to SL6).
- Update disk servers to SL6 (ongoing)
- Update to Castor version 2.1.15.
Networking:
- - Complete changes needed to remove the old core switch from the Tier1 network.
- Make routing changes to allow the removal of the UKLight Router.
Fabric
- Firmware updates on remaining EMC disk arrays (Castor, LFC)

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
117277	Green	Urgent	Waiting for Reply	2015-10-30	2015-11-03	Atlas	UK RAL-LCG2 staging error "bring-online timeout has been exceeded" (over 500 errors)
117248	Green	Less Urgent	In Progress	2015-10-28	2015-11-03		Incorrect Certificate for SRM
116866	Green	Less Urgent	On Hold	2015-10-12	2015-10-19	SNO+	snoplus support at RAL-LCG2 (pilot role)
116864	Green	Urgent	In Progress	2015-10-12	2015-10-26	CMS	T1_UK_RAL AAA opening and reading test failing again...

Availability Report

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
28/10/15	100	100	100	100	100	97	100
29/10/15	100	100	100	100	100	93	100
30/10/15	100	100	100	100	100	100	100
31/10/15	100	100	100	100	100	100	100
01/11/15	100	100	100	100	100	100	100
02/11/15	100	100	100	100	96	100	100	Single SRM test failure. "could not open connection to srm-lhcb.gridpp.rl.ac.uk"
03/11/15	100	100	100	100	100	91	100

@@ Line 21: / Line 21: @@
 | style="background-color: #f8d6a9; border-bottom: 1px solid silver; text-align: center; font-size: 1em; font-weight: bold; margin-top: 0; margin-bottom: 0; padding-top: 0.1em; padding-bottom: 0.1em;" | Resolved Disk Server Issues
 |}
-* gdss665 (AtlasTape - D0T1) failed on Sat (24th Oct). This server is still with the fabric team.
+* gdss665 (AtlasTape - D0T1) failed on Sat (24th Oct). Following a disk replacement and updating the firmware in the disk controller the system was re-run through the acceptance testing for 5 days before being returned to service yesterday (3rd November).
-* gdss663 (AtlasTape - D0T1) failed on Sun (25th Oct). This server is still with the fabric team.
+* gdss663 (AtlasTape - D0T1) failed on Sun (25th Oct). Following a disk and battery replacement and updating the firmware in the disk controller the system was re-run through the acceptance testing for 5 days before being returned to service yesterday (3rd November).
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