db1159 needs to be rebooted
Let's promote db1164 to master

When: Monday 29th Aug at 8:30AM UTC
Impact: Read only for a few seconds on the services below:

Services running on m2:

• otrs
• debmonitor
• xhgui
• recommendationapi
• iegreview
• scholarships T243037: Shutdown scholarships.wikimedia.org and archive project
• sockpuppet
• mwaddlink

Switchover steps:

OLD MASTER: db1159

NEW MASTER: db1164

Check configuration differences between new and old master

• $ pt-config-diff h=db1159.eqiad.wmnet,F=/root/.my.cnf h=db1164.eqiad.wmnet,F=/root/.my.cnf
• Silence alerts on all hosts
• Topology changes: move everything under db1164

db-switchover --timeout=1 --only-slave-move db1159.eqiad.wmnet db1164.eqiad.wmnet

• Disable puppet @db1159 and puppet @db1164 puppet agent --disable "switchover to db1164"
• Merge gerrit: https://gerrit.wikimedia.org/r/c/operations/puppet/+/827398
• Run puppet on dbproxy1013 and dbproxy1015 and check the config

puppet agent -tv && cat /etc/haproxy/conf.d/db-master.cfg

• Start the failover

!log Failover m2 from db1159 to db1164 - T316202

root@cumin1001:~/wmfmariadbpy/wmfmariadbpy# db-switchover --skip-slave-move db1159 db1164

• Reload haproxies

dbproxy1013:   systemctl reload haproxy && echo "show stat" | socat /run/haproxy/haproxy.sock stdio
dbproxy1015:   systemctl reload haproxy && echo "show stat" | socat /run/haproxy/haproxy.sock stdio

• kill connections on the old master (db1159)

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): db1159 and db1164

puppet agent --enable && run-puppet-agent

• Check services affected (otrs, debmonitor etc)
• Clean orchestrator heartbeat to remove the old masters' one:
  • server_id=171966512
• Create floating ticket for db1159 to be moved to m3: T316500
• Update/resolve phabricator ticket about failover