Difference between revisions of "Tier1 Operations Report 2016-10-05"

Revision as of 10:12, 5 October 2016

Review of Issues during the week 28th September to 5th October 2016.

At last week's meeting we reported a problem with one of the OPN link with one of the links not working outbound. This was resolved on Thursday morning (22nd Sep). It was found the relevant protocol (ECMP) had been reset in UKLight Router. This was re-configured and the problem fixed.
On Sunday morning, there were problems with all three top-level BDIIs that lasted an hour or so. The automatic re-starters fixed it although the cause is not understood.

Resolved Disk Server Issues

GDSS738 (LHCbDst - D1T0) failed late on Friday evening (30th Sep). A single faulty disk drive was found. It was returned to service initially read-only around lunchtime on Sunday (2nd Oct) and to full production on Tuesday (4th Oct).

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.
The intermittent, low-level, load-related packet loss seen over external connections is still being tracked.

Ongoing Disk Server Issues

GDSS677 (CMSTape - D0T1) failed on Thursday afternoon, 29th Sep. There are no files awaiting migration to tape on the server.

Notable Changes made since the last meeting.

Firmware updates were carried out those Castor disk servers from the Clustervision '11 batch for which this had not yet been done.
Arc-ce04 was re-installed on the Windows Hyper-V 2012 infrastructure with a bigger disk.
(Ongoing at time of meeting - replace UKLight router)

Declared in the GOC DB

Service	Scheduled?	Outage/At Risk	Start	End	Duration	Reason
All Storage (all SRM endpoints)	SCHEDULED	WARNING	05/10/2016 09:00	05/10/2016 15:00	6 hours	Series of breaks in the external data path to/from our storage while the network router is replaced and tests carried out on the resilience of the links. Internal access to storage unaffected.

Advanced warning for other interventions

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

Listing by category:

Replace the UKLight Router including upgrading the 'bypass' link to the RAL border routers to 40Gbit. Being scheduled for Wednesday 5th October.
Intervention on Tape Libraries - early November.

Listing by category:

Castor:
- Update SRMs to new version, including updating to SL6. This will be done after the Castor 2.1.15 update.
- Update to Castor version 2.1.15. Planning to roll out January 2017.
- Migration of LHCb data from T10KC to T10KD tapes.
Networking:
- Replace the UKLight Router. Then upgrade the 'bypass' link to the RAL border routers to 40Gbit.
Fabric
- Firmware updates on older disk servers.

Entries in GOC DB starting since the last report.

Service	Scheduled?	Outage/At Risk	Start	End	Duration	Reason
All Storage (all SRM endpoints)	SCHEDULED	WARNING	05/10/2016 09:00	05/10/2016 15:00	6 hours	Series of breaks in the external data path to/from our storage while the network router is replaced and tests carried out on the resilience of the links. Internal access to storage unaffected.
lcgbdii.gridpp.rl.ac.uk	UNSCHEDULED	OUTAGE	04/10/2016 07:00	04/10/2016 13:29	6 hours and 29 minutes	We have an ongoing problem affecting all three of our production Top-BDII systems that are behind the alias.
arc-ce04.gridpp.rl.ac.uk	SCHEDULED	OUTAGE	23/09/2016 10:00	30/09/2016 18:00	7 days, 8 hours	ARC-CE04 being drained ahead of a reconfiguration and move to run on different infrastructure.

Open GGUS Tickets (Snapshot during morning of meeting)


GGUS ID	Level	Urgency	State	Creation	Last Update	VO	Subject
124188	Green	Less Urgent	In Progress	2016-10-03	2016-10-03	Atlas	UK Lpad-RAL-LCG224 : Frontier squid down
123504	Yellow	Less Urgent	Waiting for Reply	2016-08-19	2016-09-20	T2K	proxy expiration
122827	Green	Less Urgent	Waiting for Reply	2016-07-12	2016-09-14	SNO+	Disk area at RAL
121687	Red	Less Urgent	On Hold	2016-05-20	2016-09-30		packet loss problems seen on RAL-LCG perfsonar
120350	Yellow	Less Urgent	On Hold	2016-03-22	2016-08-09	LSST	Enable LSST at RAL
117683	Amber	Less Urgent	On Hold	2015-11-18	2016-04-05		CASTOR at RAL not publishing GLUE 2

Availability Report

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
28/09/16	100	100	100	98	100	N/A	100	Single SRM test failure because of a user timeout error
29/09/16	100	100	100	98	100	N/A	100	Single SRM test failure because of a user timeout error
30/09/16	100	100	100	100	100	N/A	100
01/10/16	100	100	100	100	100	N/A	100
02/10/16	100	100	100	100	100	N/A	100
03/10/16	100	100	100	100	100	N/A	N/A
04/10/16	100	100	100	100	100	N/A	100

@@ Line 44: / Line 44: @@
 | 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;" | Ongoing Disk Server Issues
 |}
-* GDSS677 (CMSTape - D0T1) failed on Thursday afternoon, 29th Sep. There are no file awaiting migration to tape on the server.
+* GDSS677 (CMSTape - D0T1) failed on Thursday afternoon, 29th Sep. There are no files awaiting migration to tape on the server.
 <!-- ***************End Ongoing Disk Server Issues**************** ----->
 <!-- ************************************************************* ----->