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In Progress

Date

13 May 2021

Authors

Joseph (Pepe) Kelly

Status

Done

Summary

https://hee-tis.atlassian.net/browse/TIS21-1578

Impact

NDW was a day out of date for some records. Revalidation and GMC Connections data was out-of-date

Table of Contents

Non-technical Description

A number of nightly jobs didn’t run because the application that runs them died. We restarted the application and manually triggered the jobs that are usually run on a schedule.

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Trigger

  • Jenkins died: Service Unavailable / not functioning properly

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Detection

Build Server: Alerting via slack and team messages (Scrum Master)

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Reval: User message on MS Teams

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Resolution

  • Restarted Service

  • Reran NDW and GMC jobs

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Timeline

  • ???

  • : 15:16 BST - Jenkins raising exceptions

  • : 00:17 BST - Jenkins stopped logging

  • : 06:55 BST - Super-Scrum master flagged not only downtime but also additional consequences

    • There was an unrelated failure mentioned (STAGE PersonSync job)

  • : 07:25 BST - Jenkins restarted

  • : 07:30 BST - NDW jobs restarted

  • : 08:24 BST - Question about Revalidation jobs raised on MS Teams

  • : 08:25 BST - NDW jobs finished

  • : ??:?? 08:50- BST - gmc-sync jobs rerun

  • : ??09:?? 27 BST - confirmed with reval users data had been refreshed

  • : 10:27 BST - Downstream NDW ETLs finished

Root Cause(s)

  • NDW & Reval jobs didn’t run

  • Jenkins was unresponsive; service was up but not doing anything

  • Possibly not having write permissions?

  • Server Memory usage

  • Lots of builds were running (Reuben Roberts going to look at dependabot builds)

    Builds taking longer than they should have done not finishing
  • Jenkins had crashed due to an out-of-memory error. From the syslog:

    • May 12 23:18:25 HEE-TIS-VM-JENKINS kernel: [1052434.449590] Out of memory: Kill process 1641 (java) score 49 or sacrifice child
      May 12 23:18:25 HEE-TIS-VM-JENKINS kernel: [1052434.454439] Killed process 1641 (java) total-vm:10346296kB, anon-rss:2037444kB, file-rss:0kB
      ...
      May 12 23:19:20 HEE-TIS-VM-JENKINS jenkins: jenkins: fatal: client (pid 1641) killed by signal 9, exiting

  • When it restarted, it had lost write-permission on some of the data folders. From the jenkins log:

    • 2021-05-13 06:26:29.918+0000 [id=22] INFO jenkins.model.Jenkins#<init>: deleting obsolete workspace /home/jenkins/data/jenkins/workspace/E_TIS-EsrDataExportService_PR-64
      2021-05-13 06:26:30.562+0000 [id=22] WARNING jenkins.model.Jenkins#<init>: Exception in onOnline() for the computer listener class jenkins.branch.WorkspaceLocatorImpl$Collector on the Jenkins master node
      Also: java.nio.file.FileSystemException: /home/jenkins/data/jenkins/workspace/E_TIS-EsrDataExportService_PR-64/build/reports/tests/test/packages/com.hee.tis.esr.esrdataexport.integration.notification.html: Operation not permitted

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Action Items

Action Items

Owner

Ticket ref

Establish how to manage dependabot PRs:

  • what manual tests/checks?

  • should we routinely rebase?

  • what do we do with failing PR builds?

This might be covered best to cover in the Dev Handbook.

https://hee-tis.atlassian.net/browse/TIS21-1588

Change the dependabot config: don’t auto-rebase (Existing dependabot Tech Improvement)

  • ESR to start with (small subtask)

https://hee-tis.atlassian.net/browse/TIS21-1586

Move nightly jobs away from Jenkins/build server i.e. ECS

https://hee-tis.atlassian.net/browse/TIS21-1318 will probably encompass https://hee-tis.atlassian.net/browse/TIS21-1587

[Unrelated] Check Elastic Search snapshots are configured as needed: Maintenance windows avoid Sync job on stage and Prod (small subtask)

Andy Dingley

https://hee-tis.atlassian.net/browse/TIS21-1585

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Lessons Learned