Tier1 Operations Report 2018-12-03

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RAL Tier1 Operations Report for 27th November 2018

Review of Issues during the week 20th November to the 27th November 2018.
  • PPD Tier-2 reverted its switch to IPv6. This resolved a variety of problems for the Tier-2 some of which were being blamed on the Tier-1 (e.g. FTS service failures).
  • We believe the CMS AAA issues have been resolved. We will close the tickets but are continuing to look at ways of building more resilience in to the service. The change that appears to have fixed the problems were made on the 23rd November. This change reduced the chunk size being requested from Echo from 64MB to 4MB meaning that small data requests would be served much faster, with a slight (~10%) reduction in performance for large data requests. These changes were only made to the CMS AAA service. Since then the SAM tests have been all passing. 90% of the the CMS AAA Hammer Cloud test jobs have been passing, which is extremely good. The Hammer Cloud tests involve jobs at other sites requesting data from RAL. There can be a significant failure rate that is nothing to do with the site and anything above 70% success rate is considered a pass. The throughput on the proxy machines is much more balanced with the new chunk size in place.
  • The problem report by NA62 in the previous week, when they couldn’t recall data in a timely manner, was the result of a forgotten cron job on the new system. This cron assigns new media to tape pools as they run short. The ATLAS tape pool ran out of tapes and a 200 000 file backlog built up before this was noticed. The tape system priorities writing to tape above recalls (to ensure data is safe), and therefore once the problem was fixed, the next ~48 hours were dominated with clearing this back log.
  • Since 22nd November, SAM tests against the (Old - tape only) CMS Castor instance appear to be "missing" from the reports (and in some plots appear to indicate 100% failure). If we check the actual results they are passing. Do not currently understand the issue, migration to new endpoint is only a week away.
Current operational status and issues
  • NTR
Resolved Castor Disk Server Issues
Machine VO DiskPool dxtx Comments
- - - - -
Ongoing Castor Disk Server Issues
Machine VO DiskPool dxtx Comments
- - - - -
Limits on concurrent batch system jobs.
  • None currently enforced.
Notable Changes made since the last meeting.
  • NTR
Entries in GOC DB starting since the last report.
Service ID Scheduled? Outage/At Risk Start End Duration Reason
- - - - - - - -
Declared in the GOC DB
Service ID Scheduled? Outage/At Risk Start End Duration Reason
- - - - - - - -
  • No ongoing downtime
  • No downtime scheduled in the GOCDB for next 2 weeks
Advanced warning for other interventions
The following items are being discussed and are still to be formally scheduled and announced.

Listing by category:

  • DNS servers will be rolled out within the Tier1 network.
Open

GGUS Tickets (Snapshot taken during morning of the meeting).

Request id Affected vo Status Priority Date of creation Last update Type of problem Subject Scope
138613 cms in progress urgent 29/11/2018 03/12/2018 CMS_Data Transfers RAL Staging request WLCG
138584 cms in progress urgent 28/11/2018 30/11/2018 CMS_AAA WAN Access T1_UK_RAL xrootd reads timing out WLCG
138500 cms in progress urgent 26/11/2018 28/11/2018 CMS_Data Transfers Transfers failing from T2_PL_Swierk to RAL WLCG
138493 cms reopened urgent 26/11/2018 03/12/2018 CMS_Data Transfers Transfers failing from RAL to T2_CH_CERN WLCG
138461 lhcb in progress less urgent 22/11/2018 26/11/2018 Information System RAL Top-BDII has OLD RETIRED Bristol Site-BDII not new Production GOC-DB Site-BDII in its info EGI
138361 t2k.org in progress less urgent 19/11/2018 01/12/2018 Other RAL-LCG2: t2k.org LFC to DFC transition EGI
138033 atlas in progress urgent 01/11/2018 30/11/2018 Other singularity jobs failing at RAL EGI
137897 enmr.eu in progress less urgent 23/10/2018 28/11/2018 Accounting enmr.eu accounting at RAL EGI
GGUS Tickets Closed Last week
Request id Affected vo Status Priority Date of creation Last update Type of problem Subject Scope
138331 cms closed urgent 16/11/2018 03/12/2018 CMS_Data Transfers Posible expired proxy at RAL WLCG
138315 cms closed urgent 15/11/2018 03/12/2018 CMS_Data Transfers Transfers failing from T2_US_Wisconsin to T1_UK_RAL_Disk WLCG
137822 lhcb solved top priority 18/10/2018 04/12/2018 File Transfer FTS server seems in bad state. WLCG

Availability Report

Target Availability for each site is 97.0% Red <90% Orange <97%
Day Atlas Atlas-Echo CMS LHCB Alice OPS Comments
2018-11-14 100 100 100 100 100 100
2018-11-15 100 100 100 100 96 100
2018-11-16 100 100 100 100 100 100
2018-11-17 100 100 100 100 100 100
2018-11-18 100 100 35 100 100 100 CMS problem was the CE tests not running, see GGUS#138351.
2018-11-19 100 100 45 100 100 100 CMS problem was the CE tests not running, see GGUS#138351.
2018-11-20 100 100 56 100 100 87 CMS problem was the CE tests not running, see GGUS#138351.
Hammercloud Test Report
Target Availability for each site is 97.0% Red <90% Orange <97%
Day Atlas HC CMS HC Comment
2018-11-06 98 100
2018-11-07 100 99
2018-11-08 100 99
2018-11-09 100 98
2018-11-10 100 96
2018-11-11 100 92
2018-11-12 100 99
2018-11-13 100 99

Key: Atlas HC = Atlas HammerCloud (Queue RAL-LCG2_UCORE, Template 841); CMS HC = CMS HammerCloud

Notes from Meeting.