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Switchover s8 codfw master (db2161 -> db2165)
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Description

Checklist:

NEW primary: db2165
OLD primary: db2161

  • Check configuration differences between new and old primary:
sudo pt-config-diff --defaults-file /root/.my.cnf h=db2161.codfw.wmnet h=db2165.codfw.wmnet

Failover prep:

  • Silence alerts on all hosts:
sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover s8 T318892" 'A:db-section-s8'
  • Set NEW primary with weight 0 (and depool it from API or vslow/dump groups if it is present).
sudo dbctl instance db2165 set-weight 0
sudo dbctl config commit -m "Set db2165 with weight 0 T318892"
  • Topology changes, move all replicas under NEW primary
sudo db-switchover --replicating-master --read-only-master --timeout=25 --only-slave-move db2161 db2165
  • Disable puppet on both nodes
sudo cumin 'db2161* or db2165*' 'disable-puppet "primary switchover T318892"'

Failover:

  • Log the failover:
!log Starting s8 codfw failover from db2161 to db2165 - T318892
  • Switch primaries:
sudo db-switchover --replicating-master --read-only-master  --skip-slave-move db2161 db2165
echo "===== db2161 (OLD)"; sudo db-mysql db2161 -e 'show slave status\G'
echo "===== db2165 (NEW)"; sudo db-mysql db2165 -e 'show slave status\G'
  • Promote NEW primary in dbctl, and remove read-only
sudo dbctl --scope codfw section s8 set-master db2165
sudo dbctl config commit -m "Promote db2165 to s8 codfw primary T318892"
  • Restart puppet on both hosts:
sudo cumin 'db2161* or db2165*' 'run-puppet-agent -e "primary switchover T318892"'

Clean up tasks:

  • Clean up heartbeat table(s).
sudo db-mysql db2165 heartbeat -e "delete from heartbeat where file like 'db2161%';"
  • change events for query killer:
events_coredb_master.sql on the new primary db2165
events_coredb_slave.sql on the new slave db2161
  • Update candidate primary dbctl and orchestrator notes
sudo dbctl instance db2161 set-candidate-master --section s8 true
sudo dbctl instance db2165 set-candidate-master --section s8 false
(dborch1001): sudo orchestrator-client -c untag -i db2165 --tag name=candidate
(dborch1001): sudo orchestrator-client -c tag -i db2161 --tag name=candidate
sudo db-mysql db1115 zarcillo -e "select * from masters where section = 's8';"
  • (If needed): Depool db2161 for maintenance.
sudo dbctl instance db2161 depool
sudo dbctl config commit -m "Depool db2161 T318892"
  • Change db2161 weight to mimic the previous weight db2165:
sudo dbctl instance db2161 edit
  • Update/resolve this ticket.

Event Timeline

Marostegui triaged this task as Medium priority.Sep 29 2022, 6:52 AM
Marostegui added a project: DBA.
Marostegui updated the task description. (Show Details)
Marostegui updated the task description. (Show Details)

Change 836691 had a related patch set uploaded (by Marostegui; author: Marostegui):

[operations/puppet@production] mariadb: Promote db2165 to s8 codfw master

https://gerrit.wikimedia.org/r/836691

Marostegui moved this task from Triage to In progress on the DBA board.

Mentioned in SAL (#wikimedia-operations) [2022-09-29T10:50:05Z] <marostegui@cumin1001> START - Cookbook sre.hosts.downtime for 1:00:00 on 30 hosts with reason: Primary switchover s7 T318892

Mentioned in SAL (#wikimedia-operations) [2022-09-29T10:50:26Z] <marostegui@cumin1001> END (PASS) - Cookbook sre.hosts.downtime (exit_code=0) for 1:00:00 on 30 hosts with reason: Primary switchover s7 T318892

Mentioned in SAL (#wikimedia-operations) [2022-09-29T10:50:48Z] <marostegui@cumin1001> START - Cookbook sre.hosts.downtime for 1:00:00 on 30 hosts with reason: Primary switchover s8 T318892

Mentioned in SAL (#wikimedia-operations) [2022-09-29T10:51:09Z] <marostegui@cumin1001> END (PASS) - Cookbook sre.hosts.downtime (exit_code=0) for 1:00:00 on 30 hosts with reason: Primary switchover s8 T318892

Mentioned in SAL (#wikimedia-operations) [2022-09-29T10:52:06Z] <marostegui@cumin1001> dbctl commit (dc=all): 'Set db2165 with weight 0 T318892', diff saved to https://phabricator.wikimedia.org/P35154 and previous config saved to /var/cache/conftool/dbconfig/20220929-105206-root.json

Change 836691 merged by Marostegui:

[operations/puppet@production] mariadb: Promote db2165 to s8 codfw master

https://gerrit.wikimedia.org/r/836691

Mentioned in SAL (#wikimedia-operations) [2022-09-29T11:10:45Z] <marostegui> Starting s8 codfw failover from db2161 to db2165 - T318892

Mentioned in SAL (#wikimedia-operations) [2022-09-29T11:11:27Z] <marostegui@cumin1001> dbctl commit (dc=all): 'Promote db2165 to s8 codfw primary T318892', diff saved to https://phabricator.wikimedia.org/P35156 and previous config saved to /var/cache/conftool/dbconfig/20220929-111127-root.json

Mentioned in SAL (#wikimedia-operations) [2022-09-29T11:12:17Z] <marostegui@cumin1001> dbctl commit (dc=all): 'Depool db2161 T318892', diff saved to https://phabricator.wikimedia.org/P35157 and previous config saved to /var/cache/conftool/dbconfig/20220929-111217-root.json

Marostegui updated the task description. (Show Details)

Done