Databases on m5:
```
labsdbaccounts
mailman3
mailman3web
striker
test_labsdbaccounts
toolhub
```
**Impact: Writes will be disabled for around 15-30 seconds.**
Failover process
OLD MASTER: db1164
NEW MASTER: db1228
[] Check configuration differences between new and old master
`pt-config-diff h=db1164.eqiad.wmnet,F=/root/.my.cnf h=db1228.eqiad.wmnet,F=/root/.my.cnf `
[] Silence alerts on all hosts: `sudo cookbook sre.hosts.downtime --minutes 60 -r "m5 master switch T432967" 'A:db-section-m5'`
[] Topology changes: move everything under db1228
`sudo db-switchover --timeout=15 --only-slave-move db1164.eqiad.wmnet db1228.eqiad.wmnet`
[] Disable puppet db1164 and db1228
`sudo cumin 'db1164* or db1228*' 'disable-puppet "primary switchover T432967"'`
[] Merge gerrit:
[] Run puppet on dbproxy1027 and dbproxy1029 and check the config
`run-puppet-agent && cat /etc/haproxy/conf.d/db-master.cfg`
[] Start the failover: `!log Failover m5 from db1164 to db1228 - T432967 `
[] DB switchover
`root@cumin1001:~/wmfmariadbpy/wmfmariadbpy# db-switchover --skip-slave-move db1164 db1228`
[] Reload haproxies (dbproxy1029 is the active one)
```
dbproxy1027: systemctl reload haproxy && echo "show stat" | socat /run/haproxy/haproxy.sock stdio
dbproxy1029: systemctl reload haproxy && echo "show stat" | socat /run/haproxy/haproxy.sock stdio
```
[] kill connections on the old master (db1164)
` pt-kill --print --kill --victims all --match-all F=/dev/null,S=/run/mysqld/mysqld.sock`
[] Restart puppet on old and new masters (for heartbeat):db1164 and db1228
`sudo cumin 'db1164* or db1228*' 'run-puppet-agent -e "primary switchover T432967"'`
[] Check affected services
[] Clean orchestrator heartbeat to remove the old masters' one, otherwise Orchestrator will show lag:
** `sudo db-mysql db1228 heartbeat -e "delete from heartbeat where file like 'db1164%';"`