MySQL upgrade fails on Ubuntu 16.04 - mysql

Question

I have Ubuntu 16.04 running (clean install - no upgrade). MySQL is running fine - but I get this error when I try to update MySQL:
apt-get install
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
2 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up mysql-server-5.7 (5.7.16-0ubuntu0.16.04.1) ...
Checking if update is needed.
Checking server version.
Running queries to upgrade MySQL server.
Checking system database.
mysql.columns_priv OK
mysql.db OK
mysql.engine_cost OK
mysql.event OK
mysql.func OK
mysql.general_log OK
mysql.gtid_executed OK
mysql.help_category OK
mysql.help_keyword OK
mysql.help_relation OK
mysql.help_topic OK
mysql.innodb_index_stats OK
mysql.innodb_table_stats OK
mysql.ndb_binlog_index OK
mysql.plugin OK
mysql.proc OK
mysql.procs_priv OK
mysql.proxies_priv OK
mysql.server_cost OK
mysql.servers OK
mysql.slave_master_info OK
mysql.slave_relay_log_info OK
mysql.slave_worker_info OK
mysql.slow_log OK
mysql.tables_priv OK
mysql.time_zone OK
mysql.time_zone_leap_second OK
mysql.time_zone_name OK
mysql.time_zone_transition OK
mysql.time_zone_transition_type OK
mysql.user OK
The sys schema is already up to date (version 1.5.1).
Checking databases.
ALL DATABASES RETURNED OK
Error occurred: Error during call to mysql_check.
mysql_upgrade failed with exit status 4
dpkg: error processing package mysql-server-5.7 (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mysql-server:
mysql-server depends on mysql-server-5.7; however:
Package mysql-server-5.7 is not configured yet.
dpkg: error processing package mysql-server (--configure):
dependency problems - leaving unconfigured
Errors were encountered while processing:
mysql-server-5.7
mysql-server
E: Sub-process /usr/bin/dpkg returned an error code (1)
Although it's running, I dont like errors. Do you guys have any idea how to fix this issue?
Running dpkg -l | grep mysql gives:
dpkg -l | grep mysql
ii libdbd-mysql-perl 4.033-1ubuntu0.1 amd64 Perl5 database interface to the MySQL database
ii libmysqlclient20:amd64 5.7.16-0ubuntu0.16.04.1 amd64 MySQL database client library
ii mysql-client 5.7.16-0ubuntu0.16.04.1 all MySQL database client (metapackage depending on the latest version)
ii mysql-client-5.7 5.7.16-0ubuntu0.16.04.1 amd64 MySQL database client binaries
ii mysql-client-core-5.7 5.7.16-0ubuntu0.16.04.1 amd64 MySQL database core client binaries
ii mysql-common 5.7.16-0ubuntu0.16.04.1 all MySQL database common files, e.g. /etc/mysql/my.cnf
iU mysql-server 5.7.16-0ubuntu0.16.04.1 all MySQL database server (metapackage depending on the latest version)
iF mysql-server-5.7 5.7.16-0ubuntu0.16.04.1 amd64 MySQL database server binaries and system database setup
ii mysql-server-core-5.7 5.7.16-0ubuntu0.16.04.1 amd64 MySQL database server binaries
ii php-mysql 1:7.0+45+deb.sury.org~xenial+1 all MySQL module for PHP [default]
ii php5.6-mysql 5.6.27-1+deb.sury.org~xenial+1 amd64 MySQL module for PHP
ii php7.0-mysql 7.0.12-1+deb.sury.org~xenial+1 amd64 MySQL module for PHP
Thanks

Answer 1

I've run into this myself and I believe it has to do with how the upgrade process stops/starts/restarts MySQL.
Here is my workaround that I do after an attempted upgrade of MySQL fails.
Start MySQL normally, typically "service mysql start" as root.
As root execute "mysql_upgrade --defaults-file=/etc/mysql/debian.cnf". Hopefully it should complete with no errors or indicate that MySQL is already upgraded.
Edit the file "/var/lib/dpkg/info/mysql-server-5.7.postinst" with your favorite editor. Around line 320 (depending on version) find the line "mysql_upgrade --defaults-file=/etc/mysql/debian.cnf || result=$?". Comment that line out (prepend line with '#'), if should look like "#mysql_upgrade --defaults-file=/etc/mysql/debian.cnf || result=$?". Save the file and exit from the editor.
Rerun the upgrade process and it should indicate that MySQL is now upgraded.
At some point I will dig further to see why the "mysql_upgrade ..." invocation fails during the upgrade but not alone from the command line. But I've not gone through a few iterations of upgrades without issue using this method.
Hope this helps.
'Grip

Answer 2

I've had this issue before, the root cause for this issue was changing the db configuration.
I changed lower_case_table_names = 1 and set the value to one, and when I tried to upgrade it failed with the error you shared in your question.
To solve it, I simple set the value back to 0, restarted the db, and the upgrade worked well for me.
First edit the config:
sudo nano /etc/mysql/my.cnf
change this line:
lower_case_table_names = 0
restart the database
sudo /etc/init.d/mysql restart
Then run the upgrade command

Answer 3

NOTE: This is for upgrading MySQL with "mysql_secure_installation" fix.
Had problems with upgrading MySQL Server 5.7 in Ubuntu 16.04 and I finally located my problem. I enabled "mysql_secure_installation" during my first installation that causes the upgrade script to fail due to password creation error (unsatisfied special character requirement on the automatically generated password in the upgrade script).
While running 'sudo apt upgrade' or 'sudo apt install -f', the error can be traced using this command:
tail -f /var/log/mysql/error.log
In my case, the log shows:
[ERROR] 1819 Your password does not satisfy the current policy
requirements
To fix this, login to mysql and temporarily disable MySQL's validate password plugin:
mysql -u root -p -h 127.0.0.1
mysql> uninstall plugin validate_password;
mysql> exit
make sure to stop the previous upgrade/install and rerun the upgrade/install. Once done, login back to mysql and enable MySQL's validate password plugin;
mysql -u root -p -h 127.0.0.1
mysql> install plugin validate_password SONAME 'validate_password.so';
mysql> exit

Answer 4

always check /var/log/mysqld.log first