Change Details

**When:** During a pre-defined DBA maintenance windows **Affected wikis:**: https://noc.wikimedia.org/conf/highlight.php?file=dblists/s2.dblist **Checklist:** NEW primary: db2107 OLD primary: db2104 [x] Check configuration differences between new and old primary: ``` sudo pt-config-diff --defaults-file /root/.my.cnf h=db2104.codfw.wmnet h=db2107.codfw.wmnet ``` **Failover prep:** [x] Silence alerts on all hosts: ``` sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover s2 T327998" 'A:db-section-s2' ``` [x] Set NEW primary with weight 0 (and depool it from API or vslow/dump groups if it is present). ``` sudo dbctl instance db2107 set-weight 0 sudo dbctl config commit -m "Set db2107 with weight 0 T327998" ``` [] Topology changes, move all replicas under NEW primary ``` sudo db-switchover --timeout=25 --replicating-master --read-only-master --only-slave-move db2104 db2107 ``` [x] Disable puppet on both nodes ``` sudo cumin 'db2104* or db2107*' 'disable-puppet "primary switchover T327998"' ``` [x] Merge gerrit puppet change to promote NEW primary: https://gerrit.wikimedia.org/r/c/operations/puppet/+/883514/ **Failover:** [] Log the failover: ``` !log Starting s2 codfw failover from db2104 to db2107 - T327998 ``` [] Switch primaries: ``` sudo db-switchover --replicating-master --read-only-master --skip-slave-move db2104 db2107 echo "===== db2104 (OLD)"; sudo db-mysql db2104 -e 'show slave status\\G' echo "===== db2107 (NEW)"; sudo db-mysql db2107 -e 'show slave status\\G' ``` [] Promote NEW primary in dbctl ``` sudo dbctl --scope codfw section s2 set-master db2107 sudo dbctl config commit -m "Promote db2107 to s2 primary T327998" ``` [] Restart puppet on both hosts: ``` sudo cumin 'db2104* or db2107*' 'run-puppet-agent -e "primary switchover T327998"' ``` **Clean up tasks:** [] Clean up heartbeat table(s). ``` sudo db-mysql db2107 heartbeat -e "delete from heartbeat where file like 'db2104%';" ``` [] change events for query killer: ``` events_coredb_master.sql on the new primary db2107 events_coredb_slave.sql on the new slave db2104 ``` [] Update candidate primary dbctl and orchestrator notes ``` sudo dbctl instance db2104 set-candidate-master --section s2 true sudo dbctl instance db2107 set-candidate-master --section s2 false (dborch1001): sudo orchestrator-client -c untag -i db2107 --tag name=candidate (dborch1001): sudo orchestrator-client -c tag -i db2104 --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 = 's2';" ``` [] (If needed): Depool db2104 for maintenance. ``` sudo dbctl instance db2104 depool sudo dbctl config commit -m "Depool db2104 T327998" ``` [] Change db2104 weight to mimic the previous weight db2107: ``` sudo dbctl instance db2104 edit ``` [] Apply outstanding schema changes to db2104 (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/s2.dblist **Checklist:** NEW primary: db2107 OLD primary: db2104 [x] Check configuration differences between new and old primary: ``` sudo pt-config-diff --defaults-file /root/.my.cnf h=db2104.codfw.wmnet h=db2107.codfw.wmnet ``` **Failover prep:** [x] Silence alerts on all hosts: ``` sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover s2 T327998" 'A:db-section-s2' ``` [x] Set NEW primary with weight 0 (and depool it from API or vslow/dump groups if it is present). ``` sudo dbctl instance db2107 set-weight 0 sudo dbctl config commit -m "Set db2107 with weight 0 T327998" ``` [x] Topology changes, move all replicas under NEW primary ``` sudo db-switchover --timeout=25 --replicating-master --read-only-master --only-slave-move db2104 db2107 ``` [x] Disable puppet on both nodes ``` sudo cumin 'db2104* or db2107*' 'disable-puppet "primary switchover T327998"' ``` [x] Merge gerrit puppet change to promote NEW primary: https://gerrit.wikimedia.org/r/c/operations/puppet/+/883514/ **Failover:** [] Log the failover: ``` !log Starting s2 codfw failover from db2104 to db2107 - T327998 ``` [] Switch primaries: ``` sudo db-switchover --replicating-master --read-only-master --skip-slave-move db2104 db2107 echo "===== db2104 (OLD)"; sudo db-mysql db2104 -e 'show slave status\\G' echo "===== db2107 (NEW)"; sudo db-mysql db2107 -e 'show slave status\\G' ``` [] Promote NEW primary in dbctl ``` sudo dbctl --scope codfw section s2 set-master db2107 sudo dbctl config commit -m "Promote db2107 to s2 primary T327998" ``` [] Restart puppet on both hosts: ``` sudo cumin 'db2104* or db2107*' 'run-puppet-agent -e "primary switchover T327998"' ``` **Clean up tasks:** [] Clean up heartbeat table(s). ``` sudo db-mysql db2107 heartbeat -e "delete from heartbeat where file like 'db2104%';" ``` [] change events for query killer: ``` events_coredb_master.sql on the new primary db2107 events_coredb_slave.sql on the new slave db2104 ``` [] Update candidate primary dbctl and orchestrator notes ``` sudo dbctl instance db2104 set-candidate-master --section s2 true sudo dbctl instance db2107 set-candidate-master --section s2 false (dborch1001): sudo orchestrator-client -c untag -i db2107 --tag name=candidate (dborch1001): sudo orchestrator-client -c tag -i db2104 --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 = 's2';" ``` [] (If needed): Depool db2104 for maintenance. ``` sudo dbctl instance db2104 depool sudo dbctl config commit -m "Depool db2104 T327998" ``` [] Change db2104 weight to mimic the previous weight db2107: ``` sudo dbctl instance db2104 edit ``` [] Apply outstanding schema changes to db2104 (if any) [] Update/resolve this ticket.