Change Details

**When:** During a pre-defined DBA maintenance windows **Affected wikis:**: https://noc.wikimedia.org/conf/highlight.php?file=dblists/s8.dblist **Checklist:** NEW primary: db2161 OLD primary: db2165 [x] Check configuration differences between new and old primary: ``` sudo pt-config-diff --defaults-file /root/.my.cnf h=db2165.codfw.wmnet h=db2161.codfw.wmnet ``` **Failover prep:** [x] Silence alerts on all hosts: ``` sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover s8 T327754" 'A:db-section-s8' ``` [x] Set NEW primary with weight 0 (and depool it from API or vslow/dump groups if it is present). ``` sudo dbctl instance db2161 set-weight 0 sudo dbctl config commit -m "Set db2161 with weight 0 T327754" ``` [x] Topology changes, move all replicas under NEW primary ``` sudo db-switchover --timeout=25 --replicating-master --read-only-master --only-slave-move db2165 db2161 ``` [x] Disable puppet on both nodes ``` sudo cumin 'db2165* or db2161*' 'disable-puppet "primary switchover T327754"' ``` [x] Merge gerrit puppet change to promote NEW primary: https://gerrit.wikimedia.org/r/c/operations/puppet/+/882772/ **Failover:** [] Log the failover: ``` !log Starting s8 codfw failover from db2165 to db2161 - T327754 ``` [] Switch primaries: ``` sudo db-switchover --replicating-master --read-only-master --skip-slave-move db2165 db2161 echo "===== db2165 (OLD)"; sudo db-mysql db2165 -e 'show slave status\\G' echo "===== db2161 (NEW)"; sudo db-mysql db2161 -e 'show slave status\\G' ``` [] Promote NEW primary in dbctl ``` sudo dbctl --scope codfw section s8 set-master db2161 sudo dbctl config commit -m "Promote db2161 to s8 primary T327754" ``` [] Restart puppet on both hosts: ``` sudo cumin 'db2165* or db2161*' 'run-puppet-agent -e "primary switchover T327754"' ``` **Clean up tasks:** [] Clean up heartbeat table(s). ``` sudo db-mysql db2161 heartbeat -e "delete from heartbeat where file like 'db2165%';" ``` [] change events for query killer: ``` events_coredb_master.sql on the new primary db2161 events_coredb_slave.sql on the new slave db2165 ``` [] Update candidate primary dbctl and orchestrator notes ``` sudo dbctl instance db2165 set-candidate-master --section s8 true sudo dbctl instance db2161 set-candidate-master --section s8 false (dborch1001): sudo orchestrator-client -c untag -i db2161 --tag name=candidate (dborch1001): sudo orchestrator-client -c tag -i db2165 --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 db1115 zarcillo -e "select * from masters where section = 's8';" ``` [] (If needed): Depool db2165 for maintenance. ``` sudo dbctl instance db2165 depool sudo dbctl config commit -m "Depool db2165 T327754" ``` [] Change db2165 weight to mimic the previous weight db2161: ``` sudo dbctl instance db2165 edit ``` [] Apply outstanding schema changes to db2165 (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/s8.dblist **Checklist:** NEW primary: db2161 OLD primary: db2165 [x] Check configuration differences between new and old primary: ``` sudo pt-config-diff --defaults-file /root/.my.cnf h=db2165.codfw.wmnet h=db2161.codfw.wmnet ``` **Failover prep:** [x] Silence alerts on all hosts: ``` sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover s8 T327754" 'A:db-section-s8' ``` [x] Set NEW primary with weight 0 (and depool it from API or vslow/dump groups if it is present). ``` sudo dbctl instance db2161 set-weight 0 sudo dbctl config commit -m "Set db2161 with weight 0 T327754" ``` [x] Topology changes, move all replicas under NEW primary ``` sudo db-switchover --timeout=25 --replicating-master --read-only-master --only-slave-move db2165 db2161 ``` [x] Disable puppet on both nodes ``` sudo cumin 'db2165* or db2161*' 'disable-puppet "primary switchover T327754"' ``` [x] Merge gerrit puppet change to promote NEW primary: https://gerrit.wikimedia.org/r/c/operations/puppet/+/882772/ **Failover:** [x] Log the failover: ``` !log Starting s8 codfw failover from db2165 to db2161 - T327754 ``` [] Switch primaries: ``` sudo db-switchover --replicating-master --read-only-master --skip-slave-move db2165 db2161 echo "===== db2165 (OLD)"; sudo db-mysql db2165 -e 'show slave status\\G' echo "===== db2161 (NEW)"; sudo db-mysql db2161 -e 'show slave status\\G' ``` [] Promote NEW primary in dbctl ``` sudo dbctl --scope codfw section s8 set-master db2161 sudo dbctl config commit -m "Promote db2161 to s8 primary T327754" ``` [] Restart puppet on both hosts: ``` sudo cumin 'db2165* or db2161*' 'run-puppet-agent -e "primary switchover T327754"' ``` **Clean up tasks:** [] Clean up heartbeat table(s). ``` sudo db-mysql db2161 heartbeat -e "delete from heartbeat where file like 'db2165%';" ``` [] change events for query killer: ``` events_coredb_master.sql on the new primary db2161 events_coredb_slave.sql on the new slave db2165 ``` [] Update candidate primary dbctl and orchestrator notes ``` sudo dbctl instance db2165 set-candidate-master --section s8 true sudo dbctl instance db2161 set-candidate-master --section s8 false (dborch1001): sudo orchestrator-client -c untag -i db2161 --tag name=candidate (dborch1001): sudo orchestrator-client -c tag -i db2165 --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 db1115 zarcillo -e "select * from masters where section = 's8';" ``` [] (If needed): Depool db2165 for maintenance. ``` sudo dbctl instance db2165 depool sudo dbctl config commit -m "Depool db2165 T327754" ``` [] Change db2165 weight to mimic the previous weight db2161: ``` sudo dbctl instance db2165 edit ``` [] Apply outstanding schema changes to db2165 (if any) [] Update/resolve this ticket.