Page MenuHomePhabricator

Switchover s2 master (db2204 -> db2207)
Closed, ResolvedPublic

Description

When: During a pre-defined DBA maintenance windows

Affected wikis:: https://noc.wikimedia.org/conf/highlight.php?file=dblists/s2.dblist

Checklist:

NEW primary: db2207
OLD primary: db2204

  • Check configuration differences between new and old primary:
sudo pt-config-diff --defaults-file /root/.my.cnf h=db2204.codfw.wmnet h=db2207.codfw.wmnet

Failover prep:

  • Silence alerts on all hosts:
sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover s2 T367019" 'A:db-section-s2'
  • Set NEW primary with weight 0
sudo dbctl instance db2207 set-weight 0
sudo dbctl config commit -m "Set db2207 with weight 0 T367019"
  • Depool NEW from any specific group (API, vslow, dump) if present.
sudo dbctl instance db2207 edit
# If some changes were made:
sudo dbctl config commit -m "Remove db2207 from API/vslow/dump T367019"
  • Topology changes, move all replicas under NEW primary
sudo db-switchover --timeout=25 --replicating-master --read-only-master --only-slave-move db2204 db2207
  • Disable puppet on both nodes
sudo cumin 'db2204* or db2207*' 'disable-puppet "primary switchover T367019"'

Failover:

  • Log the failover:
!log Starting s2 codfw failover from db2204 to db2207 - T367019
  • Switch primaries:
sudo db-switchover --replicating-master --read-only-master --skip-slave-move db2204 db2207
echo "===== db2204 (OLD)"; sudo db-mysql db2204 -e 'show slave status\G'
echo "===== db2207 (NEW)"; sudo db-mysql db2207 -e 'show slave status\G'
  • Promote NEW primary in dbctl
sudo dbctl --scope codfw section s2 set-master db2207
sudo dbctl config commit -m "Promote db2207 to s2 primary T367019"
  • Restart puppet on both hosts:
sudo cumin 'db2204* or db2207*' 'run-puppet-agent -e "primary switchover T367019"'

Clean up tasks:

  • Clean up heartbeat table(s).
sudo db-mysql db2207 heartbeat -e "delete from heartbeat where file like 'db2204%';"
  • change events for query killer:
events_coredb_master.sql on the new primary db2207
events_coredb_slave.sql on the new slave db2204
  • Update candidate primary dbctl and orchestrator notes
sudo dbctl instance db2204 set-candidate-master --section s2 true
sudo dbctl instance db2207 set-candidate-master --section s2 false
(dborch1001): sudo orchestrator-client -c untag -i db2207 --tag name=candidate
(dborch1001): sudo orchestrator-client -c tag -i db2204 --tag name=candidate
sudo db-mysql db1215 zarcillo -e "select * from masters where section = 's2';"
  • (If needed): Depool db2204 for maintenance.
sudo dbctl instance db2204 depool
sudo dbctl config commit -m "Depool db2204 T367019"
  • Change db2204 weight to mimic the previous weight db2207:
sudo dbctl instance db2204 edit
  • Apply outstanding schema changes to db2204 (if any)
  • Update/resolve this ticket.

Event Timeline

Change #1039605 had a related patch set uploaded (by Gerrit maintenance bot; author: Gerrit maintenance bot):

[operations/puppet@production] mariadb: Promote db2207 to s2 master

https://gerrit.wikimedia.org/r/1039605

Mentioned in SAL (#wikimedia-operations) [2024-06-10T06:38:22Z] <arnaudb@cumin1002> START - Cookbook sre.hosts.downtime for 1:00:00 on 26 hosts with reason: Primary switchover s2 T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T06:38:45Z] <arnaudb@cumin1002> END (PASS) - Cookbook sre.hosts.downtime (exit_code=0) for 1:00:00 on 26 hosts with reason: Primary switchover s2 T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T06:39:13Z] <arnaudb@cumin1002> dbctl commit (dc=all): 'Set db2207 with weight 0 T367019', diff saved to https://phabricator.wikimedia.org/P64493 and previous config saved to /var/cache/conftool/dbconfig/20240610-063912-arnaudb.json

ABran-WMF moved this task from Triage to In progress on the DBA board.

Mentioned in SAL (#wikimedia-operations) [2024-06-10T07:38:39Z] <arnaudb@cumin1002> dbctl commit (dc=all): 'Revert db2207 with weight 500 T367019', diff saved to https://phabricator.wikimedia.org/P64503 and previous config saved to /var/cache/conftool/dbconfig/20240610-073838-arnaudb.json

Mentioned in SAL (#wikimedia-operations) [2024-06-10T08:56:46Z] <arnaudb@cumin1002> START - Cookbook sre.hosts.downtime for 1:00:00 on 26 hosts with reason: Primary switchover s2 T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T08:57:08Z] <arnaudb@cumin1002> END (PASS) - Cookbook sre.hosts.downtime (exit_code=0) for 1:00:00 on 26 hosts with reason: Primary switchover s2 T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T08:57:21Z] <arnaudb@cumin1002> dbctl commit (dc=all): 'Set db2207 with weight 0 T367019', diff saved to https://phabricator.wikimedia.org/P64513 and previous config saved to /var/cache/conftool/dbconfig/20240610-085721-arnaudb.json

Mentioned in SAL (#wikimedia-operations) [2024-06-10T09:14:23Z] <arnaudb> Starting s2 codfw failover from db2204 to db2207 - T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T09:15:07Z] <arnaudb@cumin1002> dbctl commit (dc=all): 'Promote db2207 to s2 primary T367019', diff saved to https://phabricator.wikimedia.org/P64515 and previous config saved to /var/cache/conftool/dbconfig/20240610-091506-arnaudb.json

Mentioned in SAL (#wikimedia-operations) [2024-06-10T09:54:50Z] <arnaudb@cumin1002> START - Cookbook sre.hosts.downtime for 5:00:00 on 870 hosts with reason: Issue from T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T09:54:54Z] <arnaudb@cumin1002> END (FAIL) - Cookbook sre.hosts.downtime (exit_code=99) for 5:00:00 on 870 hosts with reason: Issue from T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T09:57:24Z] <arnaudb@cumin1002> START - Cookbook sre.hosts.downtime for 5:00:00 on 26 hosts with reason: Issue from T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T09:57:47Z] <arnaudb@cumin1002> END (PASS) - Cookbook sre.hosts.downtime (exit_code=0) for 5:00:00 on 26 hosts with reason: Issue from T367019

Mentioned in SAL (#wikimedia-operations) [2024-06-10T10:25:12Z] <arnaudb@cumin1002> dbctl commit (dc=all): 'Depool db2204 T367019', diff saved to https://phabricator.wikimedia.org/P64518 and previous config saved to /var/cache/conftool/dbconfig/20240610-102511-arnaudb.json

ABran-WMF triaged this task as Medium priority.
ABran-WMF updated the task description. (Show Details)
ABran-WMF moved this task from In progress to Done on the DBA board.