db2144 needs to be rebooted.
**Affected wikis:**: x2
**Checklist:**
NEW primary: db2142
OLD primary: db2144
[] Check configuration differences between new and old primary:
```
sudo pt-config-diff --defaults-file /root/.my.cnf h=db2144.codfw.wmnet h=db2142.codfw.wmnet
```
**Failover prep:**
[] Silence alerts on all hosts:
```
sudo cookbook sre.hosts.downtime --hours 1 -r "Primary switchover x2 T334821" 'A:db-section-x2'
```
[] Set NEW primary with weight 0 (and depool it from API or vslow/dump groups if it is present).
```
sudo dbctl instance db2142 set-weight 0
sudo dbctl config commit -m "Set db2142 with weight 0 T334821"
```
[] Topology changes, move all replicas under NEW primary
```
This didn't work and I had to use orchestrator: sudo db-switchover --replicating-master --timeout=25 --only-slave-move db2144 db2142
```
[] Disable puppet on both nodes
```
sudo cumin 'db2144* or db2142*' 'disable-puppet "primary switchover T334821"'
```
[] Merge gerrit puppet change to promote NEW primary: TO-DO
**Failover:**
[] Log the failover:
```
!log Starting x2 codfw failover from db2144 to db2142 - T334821
```
[] Switch primaries:
```
sudo db-switchover --replicating-master --skip-slave-move db2144 db2142
echo "===== db2144 (OLD)"; sudo db-mysql db2144 -e 'show slave status\G'
echo "===== db2142 (NEW)"; sudo db-mysql db2142 -e 'show slave status\G'
```
[] Promote NEW primary in dbctl, and remove read-only
```
sudo dbctl --scope codfw section x2 set-master db2142
sudo dbctl config commit -m "Promote db2142 to x2 primary T334821"
```
[] Restart puppet on both hosts:
```
sudo cumin 'db2144* or db2142*' 'run-puppet-agent -e "primary switchover T334821"'
```
**Clean up tasks:**
[] Clean up heartbeat table(s).
```
sudo db-mysql db2142 heartbeat -e "delete from heartbeat where file like 'db2144%';"
sudo db-mysql db1151 heartbeat -e "delete from heartbeat where file like 'db2144%';"
```
[] change events for query killer:
```
events_coredb_master.sql on the new primary db2142
events_coredb_slave.sql on the new slave db2144
```
[] Update candidate primary dbctl and orchestrator notes
```
sudo dbctl instance db2144 set-candidate-master --section x2 true
sudo dbctl instance db2142 set-candidate-master --section x2 false
(dborch1001): sudo orchestrator-client -c untag -i db2142 --tag name=candidate
(dborch1001): sudo orchestrator-client -c tag -i db2144 --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 = 'x2';"
```
[] (If needed): Depool db2144 for maintenance.
```
sudo dbctl instance db2144 depool
sudo dbctl config commit -m "Depool db2144 T334821"
```
[] Change db2144 weight to mimic the previous weight db2142:
```
sudo dbctl instance db2144 edit
```
[] Update/resolve this ticket.