Change Details

**When:** During a pre-defined DBA maintenance windows **Affected wikis:**: https://noc.wikimedia.org/conf/highlight.php?file=dblists/s6.dblist **Checklist:** NEW primary: db2129 OLD primary: db2114 [x] Check configuration differences between new and old primary: ``` sudo pt-config-diff --defaults-file /root/.my.cnf h=db2114.codfw.wmnet h=db2129.codfw.wmnet ``` **Failover prep:** [x] Silence alerts on all hosts: ``` sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover s6 T363713" 'A:db-section-s6' ``` [x] Set NEW primary with weight 0 (and depool it from API or vslow/dump groups if it is present). ``` sudo dbctl instance db2129 set-weight 0 sudo dbctl config commit -m "Set db2129 with weight 0 T363713" ``` [x] Topology changes, move all replicas under NEW primary ``` sudo db-switchover --timeout=25 --replicating-master --read-only-master --only-slave-move db2114 db2129 ``` [x] Disable puppet on both nodes ``` sudo cumin 'db2114* or db2129*' 'disable-puppet "primary switchover T363713"' ``` [x] Merge gerrit puppet change to promote NEW primary: FIXME **Failover:** [] Log the failover: ``` !log Starting s6 codfw failover from db2114 to db2129 - T363713 ``` [] Switch primaries: ``` sudo db-switchover --replicating-master --read-only-master --skip-slave-move db2114 db2129 echo "===== db2114 (OLD)"; sudo db-mysql db2114 -e 'show slave status\G' echo "===== db2129 (NEW)"; sudo db-mysql db2129 -e 'show slave status\G' ``` [] Promote NEW primary in dbctl ``` sudo dbctl --scope codfw section s6 set-master db2129 sudo dbctl config commit -m "Promote db2129 to s6 primary T363713" ``` [] Restart puppet on both hosts: ``` sudo cumin 'db2114* or db2129*' 'run-puppet-agent -e "primary switchover T363713"' ``` **Clean up tasks:** [] Clean up heartbeat table(s). ``` sudo db-mysql db2129 heartbeat -e "delete from heartbeat where file like 'db2114%';" ``` [] change events for query killer: ``` events_coredb_master.sql on the new primary db2129 events_coredb_slave.sql on the new slave db2114 ``` [] Update candidate primary dbctl and orchestrator notes ``` sudo dbctl instance db2114 set-candidate-master --section s6 true sudo dbctl instance db2129 set-candidate-master --section s6 false (dborch1001): sudo orchestrator-client -c untag -i db2129 --tag name=candidate (dborch1001): sudo orchestrator-client -c tag -i db2114 --tag name=candidate ``` [] Check zarcillo was updated ** db-switchover should do this. If it fails, do it manually: https://phabricator.wikimedia.org/P13956 ``` sudo db-mysql db1215 zarcillo -e "select * from masters where section = 's6';" ``` [] (If needed): Depool db2114 for maintenance. ``` sudo dbctl instance db2114 depool sudo dbctl config commit -m "Depool db2114 T363713" ``` [] Change db2114 weight to mimic the previous weight db2129: ``` sudo dbctl instance db2114 edit ``` [] Apply outstanding schema changes to db2114 (if any) [] Update/resolve this ticket.

**When:** During a pre-defined DBA maintenance windows **Affected wikis:**: https://noc.wikimedia.org/conf/highlight.php?file=dblists/s6.dblist **Checklist:** NEW primary: db2129 OLD primary: db2114 [x] Check configuration differences between new and old primary: ``` sudo pt-config-diff --defaults-file /root/.my.cnf h=db2114.codfw.wmnet h=db2129.codfw.wmnet ``` **Failover prep:** [x] Silence alerts on all hosts: ``` sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover s6 T363713" 'A:db-section-s6' ``` [x] Set NEW primary with weight 0 (and depool it from API or vslow/dump groups if it is present). ``` sudo dbctl instance db2129 set-weight 0 sudo dbctl config commit -m "Set db2129 with weight 0 T363713" ``` [x] Topology changes, move all replicas under NEW primary ``` sudo db-switchover --timeout=25 --replicating-master --read-only-master --only-slave-move db2114 db2129 ``` [x] Disable puppet on both nodes ``` sudo cumin 'db2114* or db2129*' 'disable-puppet "primary switchover T363713"' ``` [x] Merge gerrit puppet change to promote NEW primary: FIXME **Failover:** [x] Log the failover: ``` !log Starting s6 codfw failover from db2114 to db2129 - T363713 ``` [x] Switch primaries: ``` sudo db-switchover --replicating-master --read-only-master --skip-slave-move db2114 db2129 echo "===== db2114 (OLD)"; sudo db-mysql db2114 -e 'show slave status\G' echo "===== db2129 (NEW)"; sudo db-mysql db2129 -e 'show slave status\G' ``` [x] Promote NEW primary in dbctl ``` sudo dbctl --scope codfw section s6 set-master db2129 sudo dbctl config commit -m "Promote db2129 to s6 primary T363713" ``` [x] Restart puppet on both hosts: ``` sudo cumin 'db2114* or db2129*' 'run-puppet-agent -e "primary switchover T363713"' ``` **Clean up tasks:** [] Clean up heartbeat table(s). ``` sudo db-mysql db2129 heartbeat -e "delete from heartbeat where file like 'db2114%';" ``` [] change events for query killer: ``` events_coredb_master.sql on the new primary db2129 events_coredb_slave.sql on the new slave db2114 ``` [] Update candidate primary dbctl and orchestrator notes ``` sudo dbctl instance db2114 set-candidate-master --section s6 true sudo dbctl instance db2129 set-candidate-master --section s6 false (dborch1001): sudo orchestrator-client -c untag -i db2129 --tag name=candidate (dborch1001): sudo orchestrator-client -c tag -i db2114 --tag name=candidate ``` [] Check zarcillo was updated ** db-switchover should do this. If it fails, do it manually: https://phabricator.wikimedia.org/P13956 ``` sudo db-mysql db1215 zarcillo -e "select * from masters where section = 's6';" ``` [] (If needed): Depool db2114 for maintenance. ``` sudo dbctl instance db2114 depool sudo dbctl config commit -m "Depool db2114 T363713" ``` [] Change db2114 weight to mimic the previous weight db2129: ``` sudo dbctl instance db2114 edit ``` [] Apply outstanding schema changes to db2114 (if any) [] Update/resolve this ticket.