设置 MySQL 时出错：表 'mysql.plugin' 不存在

Question

I have a MySQL 5.7 instance running without problems on Ubuntu 16, but when i try to install any other package or try to update existing ones through apt-get, i get the following error:

# apt-get upgrade

Setting up mysql-server-5.7 (5.7.20-0ubuntu0.16.04.1) ...
Checking if update is needed.
Checking server version.
Running queries to upgrade MySQL server.
mysql_upgrade: [ERROR] 1146: Table 'mysql.plugin' doesn't exist
mysql_upgrade failed with exit status 5
 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
Errors were encountered while processing:
 mysql-server-5.7
 mysql-server

And if i run a mysqlcheck , it looks like some of the system tables exists but others are missing:

mysql.columns_priv                                 OK
mysql.db                                           OK
mysql.engine_cost
Error    : Table 'mysql.engine_cost' doesn't exist
status   : Operation failed
mysql.event                                        OK
mysql.func                                         OK
mysql.general_log                                  OK
mysql.gtid_executed
Error    : Table 'mysql.gtid_executed' doesn't exist
status   : Operation failed
mysql.help_category
Error    : Table 'mysql.help_category' doesn't exist
status   : Operation failed
mysql.help_keyword
Error    : Table 'mysql.help_keyword' doesn't exist
status   : Operation failed
mysql.help_relation
Error    : Table 'mysql.help_relation' doesn't exist
status   : Operation failed
mysql.help_topic
Error    : Table 'mysql.help_topic' doesn't exist
status   : Operation failed
mysql.innodb_index_stats
Error    : Table 'mysql.innodb_index_stats' doesn't exist
status   : Operation failed
mysql.innodb_table_stats
Error    : Table 'mysql.innodb_table_stats' doesn't exist
status   : Operation failed
mysql.ndb_binlog_index                             OK
mysql.plugin
Error    : Table 'mysql.plugin' doesn't exist
status   : Operation failed
mysql.proc                                         OK
mysql.procs_priv                                   OK
mysql.proxies_priv                                 OK
mysql.server_cost
Error    : Table 'mysql.server_cost' doesn't exist
status   : Operation failed
mysql.servers
Error    : Table 'mysql.servers' doesn't exist
status   : Operation failed
mysql.slave_master_info
Error    : Table 'mysql.slave_master_info' doesn't exist
status   : Operation failed
mysql.slave_relay_log_info
Error    : Table 'mysql.slave_relay_log_info' doesn't exist
status   : Operation failed
mysql.slave_worker_info
Error    : Table 'mysql.slave_worker_info' doesn't exist
status   : Operation failed
mysql.slow_log                                     OK
mysql.tables_priv                                  OK
mysql.time_zone
Error    : Table 'mysql.time_zone' doesn't exist
status   : Operation failed
mysql.time_zone_leap_second
Error    : Table 'mysql.time_zone_leap_second' doesn't exist
status   : Operation failed
mysql.time_zone_name
Error    : Table 'mysql.time_zone_name' doesn't exist
status   : Operation failed
mysql.time_zone_transition
Error    : Table 'mysql.time_zone_transition' doesn't exist
status   : Operation failed
mysql.time_zone_transition_type
Error    : Table 'mysql.time_zone_transition_type' doesn't exist
status   : Operation failed
mysql.user                                         OK
sys.sys_config
Error    : Table 'sys.sys_config' doesn't exist
status   : Operation failed

However, the database is correctly running and if I manually check through an SQL, it looks like the tables exist.

mysql> SHOW TABLES;
+---------------------------+
| Tables_in_mysql           |
+---------------------------+
| columns_priv              |
| db                        |
| engine_cost               |
| event                     |
| func                      |
| general_log               |
| gtid_executed             |
| help_category             |
| help_keyword              |
| help_relation             |
| help_topic                |
| innodb_index_stats        |
| innodb_table_stats        |
| ndb_binlog_index          |
| plugin                    |
| proc                      |
| procs_priv                |
| proxies_priv              |
| server_cost               |
| servers                   |
| slave_master_info         |
| slave_relay_log_info      |
| slave_worker_info         |
| slow_log                  |
| tables_priv               |
| time_zone                 |
| time_zone_leap_second     |
| time_zone_name            |
| time_zone_transition      |
| time_zone_transition_type |
| user                      |
+---------------------------+

I use the innodb_file_per_table=1 setting, and the owner of /var/lib/mysql directory is correctly set to mysql user.

I would like to fix this issue without dumping existing data, but i'm running out of ideas.

Answer 1

Try running:

bash-4.2# mysql_install_db --user=mysql --ldata=/var/lib/mysql/
Installing MariaDB/MySQL system tables in '/var/lib/mysql/' ...
OK

This should install the system tables in data directory. Then restart mysql/mariadb service.

Answer 2

Finally the only thing that solved the problem was to purge and reinstall the mysql library making a backup of the database and restoring it after all the process:

# Backup database
time mysqldump -u root -p database > /var/backups/restore_backup.sql

# Backup config and data
mv /var/lib/mysql /tmp/backups/mysql-lib.bak
cp /etc/mysql/my.cnf /tmp/backups/my.cnf.bak

# Purge library
sudo apt-get remove --purge mysql-server mysql-client mysql-common
sudo apt-get autoremove
sudo apt-get autoclean

# Reinstall
sudo apt-get update
sudo apt-get install mysql-server

# Restore config
cp /tmp/backups/my.cnf.bak /etc/mysql/my.cnf
sudo service mysql restart

# Create database
mysql -u root -p
mysql> CREATE DATABASE database;

# Restore backup
time mysql -u root -p database < /var/backups/restore_backup.sql

Answer 3

I had the same problem today and I managed to solve it without the backup - reinstall - restore steps. (Though I had backup and everyone should!)

In my case, there was a plugin.ibd file in /var/lib/mysql/mysql/ directory, and the other missing tables also had files there, but maybe they were incomplete for some reason.

I did the following:

1. Moved the files of mysql.plugin table to another directory, eg: mv /var/lib/mysql/mysql/plugin.* /other/place/
2. Ran apt-get upgrade -y to see what happens. The upgrade script recreated the mysql.plugin table correctly and complained about another table.
3. I repeated steps above with the table name the upgrade script told me and after recreating 19 tables this way, the upgrade completed successfully.

All steps I made, as root of course:

cd /var/lib/mysql/mysql
mkdir temp
mv engine_cost.*               temp/
mv gtid_executed.*             temp/
mv help_category.*             temp/
mv help_keyword.*              temp/
mv help_relation.*             temp/
mv help_topic.*                temp/
mv innodb_index_stats.*        temp/
mv innodb_table_stats.*        temp/
mv plugin.*                    temp/
mv server_cost.*               temp/
mv servers.*                   temp/
mv slave_master_info.*         temp/
mv slave_relay_log_info.*      temp/
mv slave_worker_info.*         temp/
mv time_zone.*                 temp/
mv time_zone_leap_second.*     temp/
mv time_zone_name.*            temp/
mv time_zone_transition.*      temp/
mv time_zone_transition_type.* temp/
apt-get upgrade -y

I hope it helps someone.

Answer 4

This worked on CentOS 7.9.2009 w/WHM

I did not have to reinstall MySQL. I was able to automatically recreate the bad/missing tables.

as root or sudo

cd /var/lib/mysql/mysql

create directory for temp storage (always backup!)

mkdir /root/temp-mysql-mysql-bak

move files for each bad table to your temp directory

mv TABLE_NAME_HERE.* /root/temp-mysql-mysql-bak/

Examples

mv engine_cost.* /root/temp-mysql-mysql-bak/
mv time_zone.* /root/temp-mysql-mysql-bak/
mv plugin.* /root/temp-mysql-mysql-bak/

Upgrade

yum upgrade -y

MySQL Upgrade

mysql_upgrade --upgrade-system-tables --force

restart

systemctl mysql restart

Answer 5

On Arch Linux

Package: mysql 8.0.29-1 . (need to build from source)

What worked for me ( For new installation ):

1. Rename/Move your current mysql datadir away from your default data directory installation path, in general it can be located at /var/lib/mysql
2. Trigger the following command: mysqld --initialize --user=mysql --basedir=/usr --datadir=/var/lib/mysql to reinitialize the data directory for mysql
3. Proceed to your mysql datadir to check for the presence of the new 'mysql' folder and if this works for you, you may remove the previous mysql datadir ( Note : This may remove all the data previously contained in your database, proceed with caution )