Comment 5 for bug 1664025

Somehow mysqld "Normal shutdown" kicked twice around agent upgrading.

00:37 is localtime while 15:37 is UTC.

[/var/log/mysql/error.log]
...
2017-02-12 15:37:47 15242 [Note] /usr/sbin/mysqld: Normal shutdown
...
2017-02-12 15:37:52 15242 [Note] /usr/sbin/mysqld: Shutdown complete
...
2017-02-12 15:38:52 20201 [Note] /usr/sbin/mysqld: Normal shutdown
...
2017-02-12 15:38:56 20201 [Note] /usr/sbin/mysqld: Shutdown complete

[journalctl -u mysql]
Feb 12 15:37:47 juju-50b253-2 systemd[1]: Stopping LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon...
Feb 12 15:37:47 juju-50b253-2 mysql[19583]: * Stopping MySQL (Percona XtraDB Cluster) mysqld
Feb 12 15:37:52 juju-50b253-2 /etc/init.d/mysql[19644]: MySQL PID not found, pid_file detected/guessed: /var/run/mysqld/mysqld.pid
Feb 12 15:37:52 juju-50b253-2 /etc/init.d/mysql[19648]: MySQL PID not found, pid_file detected/guessed: /var/run/mysqld/mysqld.pid
Feb 12 15:37:52 juju-50b253-2 mysql[19583]: ...done.
Feb 12 15:37:52 juju-50b253-2 systemd[1]: Stopped LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon.
Feb 12 15:38:03 juju-50b253-2 systemd[1]: Starting LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon...
Feb 12 15:38:04 juju-50b253-2 mysql[20252]: * Starting MySQL (Percona XtraDB Cluster) database server mysqld
Feb 12 15:38:04 juju-50b253-2 mysql[20252]: ...done.
Feb 12 15:38:04 juju-50b253-2 systemd[1]: Started LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon.

[unit-mysql-0.log]
unit-mysql-0: 00:37:31 INFO juju.worker.upgrader desired tool version: 2.0.2
...
unit-mysql-0: 00:37:44 DEBUG unit.mysql/0.juju-log Leader unit - bootstrap required=True
unit-mysql-0: 00:37:47 INFO unit.mysql/0.juju-log Writing file /etc/mysql/percona-xtradb-cluster.conf.d/mysqld.cnf root:root 444
unit-mysql-0: 00:37:52 INFO unit.mysql/0.config-changed Unknown operation bootstrap-pxc.
unit-mysql-0: 00:37:52 INFO unit.mysql/0.config-changed * Bootstrapping Percona XtraDB Cluster database server mysqld
unit-mysql-0: 00:38:00 INFO juju.worker.leadership mysql/0 will renew mysql leadership at 2017-02-12 15:38:30.142709216 +0000 UTC
unit-mysql-0: 00:38:03 INFO unit.mysql/0.config-changed ...done.
unit-mysql-0: 00:38:04 DEBUG unit.mysql/0.juju-log Bootstrap PXC Succeeded
...

unit-mysql-0: 00:38:51 INFO juju.worker.upgrader upgrade requested from 2.0.2 to 2.0.3