mysql not restarted after mysql_upgrade

[Kived]

After installing mysql-server 5.7, the mysql_upgrade script is run but the server is not restarted following this, which leads to the following issue:

mysql> show status;
ERROR 1682 (HY000): Native table 'performance_schema'.'session_status' has the wrong structure
mysql> show variables like 'perf%';
ERROR 1682 (HY000): Native table 'performance_schema'.'session_variables' has the wrong structure

This is fixed by restarting MySQL after running the mysql_upgrade script.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.12
ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6
Uname: Linux 4.4.0-21-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: GNOME
Date: Thu Apr 21 11:14:58 2016
InstallationDate: Installed on 2015-10-28 (175 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: dist-upgrade
UpgradeStatus: Upgraded to xenial on 2016-03-07 (44 days ago)

[Robie Basak (racb)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This sounds very much like bug 1571764 so I'm marking it as a duplicate for now. If you think it is a different issue, please explain and we can un-dupe it.

[Kived (kived)]

I do not think this is a duplicate of that bug. In my case, the upgrade itself completed without any errors. After the upgrade, I could connect to MySQL, and could even issue some queries against my databases. There were just certain commands, like the ones I showed above, that would error out (and of course these commands are called by the MySQL GUI I use). Simply restarting MySQL - sudo service mysql restart - resolved the issue, so it looks like the postinst hook isn't restarting MySQL after running mysql_upgrade (which modifies the performance_schema tables).

[Robie Basak (racb)]

OK, thanks. I'm not sure that your issue is just because mysqld wasn't restarted after mysqld_upgrade, but we can fix it so that we do that. So I'm deliberately marking this as a dupe of 1576647 that I've created in case it turns out to be something different (in which case we can undupe it).