Mysql broken after update

Question

I have an up to date Ubuntu 16.04 desktop. I installed a routine update today, which included a MySQL update. Mysql is now broken.

I followed the procedure here: 16.04 upgrade broke mysql-server but now I get: service mysql start Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.

root@civet:~# systemctl status mysql.service
● mysql.service - MySQL Community Server
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: en
   Active: inactive (dead) (Result: exit-code) since Sat 2017-01-21 16:03:52 EST
  Process: 32687 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=e
  Process: 32686 ExecStart=/usr/sbin/mysqld (code=exited, status=0/SUCCESS)
  Process: 15576 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exi
 Main PID: 32686 (code=exited, status=0/SUCCESS)

Jan 21 16:03:52 civet systemd[1]: Failed to start MySQL Community Server.
Jan 21 16:03:52 civet systemd[1]: mysql.service: Unit entered failed state.
Jan 21 16:03:52 civet systemd[1]: mysql.service: Failed with result 'exit-code'.
Jan 21 16:03:52 civet systemd[1]: mysql.service: Service hold-off time over, sch
Jan 21 16:03:52 civet systemd[1]: Stopped MySQL Community Server.
Jan 21 16:03:52 civet systemd[1]: mysql.service: Start request repeated too quic
Jan 21 16:03:52 civet systemd[1]: Failed to start MySQL Community Server.
root@civet:~# service mysql stop
root@civet:~# service mysql start
Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.
root@civet:~# journalctl -xe
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysql.service has failed.
-- 
-- The result is failed.
Jan 21 16:06:09 civet systemd[1]: mysql.service: Unit entered failed state.
Jan 21 16:06:09 civet systemd[1]: mysql.service: Failed with result 'exit-code'.
Jan 21 16:06:09 civet systemd[1]: mysql.service: Service hold-off time over, sch
Jan 21 16:06:09 civet systemd[1]: Stopped MySQL Community Server.
-- Subject: Unit mysql.service has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysql.service has finished shutting down.
Jan 21 16:06:09 civet systemd[1]: mysql.service: Start request repeated too quic
Jan 21 16:06:09 civet systemd[1]: Failed to start MySQL Community Server.
-- Subject: Unit mysql.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mysql.service has failed.
-- 
-- The result is failed.

Any suggestions? Help would be appreciated.

---

Thanks. I have been using mysqldump to make daily backups for some time. I will employ automysqlbackup once I have mysql up and running again. I ran the remove --purge command, followed by the install, and this is what I got (it's been happening like this all day)

Renaming removed key_buffer and myisam-recover options (if present)
mysql_upgrade: Got error: 1524: Plugin 'mysql_old_password' is not loaded while connecting to the MySQL server
Upgrade process encountered error and will not continue.
mysql_upgrade failed with exit status 11
dpkg: error processing package mysql-server-5.7 (--configure):
 subprocess installed post-installation script returned error exit status 1
No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                                          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
Processing triggers for systemd (229-4ubuntu16) ...
Processing triggers for ureadahead (0.100.0-19) ...
Errors were encountered while processing:
 mysql-server-5.7
 mysql-server
E: Sub-process /usr/bin/dpkg returned an error code (1)

I just seem to be going around in circles. Also, the old_password workaround no longer works, so I tried set GLOBAL old_passwords=0;

If I try to connect to mysql I get: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) I have the socket set to that path in my.cnf

Answer 1

I suggest to back up, and then purge and reinstall mysql-server.

Can you install automysqlbackup ?

sudo apt-get install automysqlbackup

Then run automysqlbackup from the command-line, and make also a backup of /etc directory :

sudo /usr/sbin/automysqlbackup

sudo rsync -av /etc/ $HOME/etc-backup/

Check that automysqlbackup created the backups successfully :

sudo ls -la /var/lib/automysqlbackup/daily/

After that remove the mysql server packages, purge the configuration, and reinstall mysql-server :

sudo apt-get remove --purge mysql-server*

sudo apt-get install mysql-server

Put back your mysqldumps, by copying from the mentioned automysqlbackup "daily" dir, unzip the file, and then :

sudo mysql --defaults-file=/etc/mysql/debian.cnf

mysql> create database example-db;
mysql> quit

sudo mysql -u root -p example-db < example-db-daily.sql

Do the same for all of your databases.

Answer 2

Problem solved by reinstall (twice) of mysql. However MySQL Workbench won't connect now, with error: