Troubles with ‘mysql.utf8mb4’ => true

ℹ️ Support
1

I just installed a brand new machine with LEMP and NC 17, so there were no old legacies lurking around.

Then I ran into several problems that are all connected to the option

‘mysql.utf8mb4’ => true

in NC’s config file:

  • when a user wants to share a file or folder, no user can be found
  • the admin does not see any user on the user setting page
  • even commands line “occ files:scan --all” fail to work

All these errors can be avoided by disabling that option.

2

Sure, but some Apps require it. And if you setup your DB to encode Multibyte, it seems not to be a good idea to disable it here.

3

MariaDB is setup to use multibyte - at least I think so:

/etc/mysql/mariadb.conf.d/50-server.cnf:

character-set-server = utf8mb4
collation-server = utf8mb4_general_ci

Still, NC tells me:

In AbstractMySQLDriver.php line 106:
                                                                                                                               
  An exception occurred while executing 'SELECT `uid`, `displayname` FROM `oc_users` `u` LEFT JOIN `oc_preferences` `p` ON (`  
  userid` = `uid`) AND (`appid` = 'settings') AND (`configkey` = 'email') WHERE (`uid`  COLLATE utf8mb4_general_ci LIKE ?) OR  
   (`displayname`  COLLATE utf8mb4_general_ci LIKE ?) OR (`configvalue`  COLLATE utf8mb4_general_ci LIKE ?) ORDER BY `uid_low  
  er` ASC' with params ["%%", "%%", "%%"]:                                                                                     
                                                                                                                               
  SQLSTATE[42000]: Syntax error or access violation: 1253 COLLATION 'utf8mb4_general_ci' is not valid for CHARACTER SET 'utf8  
  '                                                                                                                            
                                                                                                                               

In PDOStatement.php line 119:
                                                                                                                               
  SQLSTATE[42000]: Syntax error or access violation: 1253 COLLATION 'utf8mb4_general_ci' is not valid for CHARACTER SET 'utf8  
  '                                                                                                                            
                                                                                                                               

In PDOStatement.php line 117:
                                                                                                                               
  SQLSTATE[42000]: Syntax error or access violation: 1253 COLLATION 'utf8mb4_general_ci' is not valid for CHARACTER SET 'utf8  
  '
4

The database indeed seems not to be configured correctly. Due to the fact that this kind of problem is addressed at least once a week, it would recommend to use the search function of this forum to find an answer on how to configure it correctly.

https://help.nextcloud.com/search?q=COLLATION%20%27utf8mb4_general_ci%27%20is%20not%20valid%20for%20CHARACTER%20SET%20%27utf8

5

Funny: I followed all the instructions found here:

https://docs.nextcloud.com/server/13/admin_manual/configuration_database/mysql_4byte_support.html

And still I get these errors.

6

funny as well: why do you use the admin manual for version 13 to configuere a v17 machine?

7

Because I did not find find any instructions concerning 4byte support on NC 17.

By the way: the instruction still seem to be same:

https://docs.nextcloud.com/server/latest/admin_manual/configuration_database/mysql_4byte_support.html

8

Supplementary question:

I can set

‘mysql.utf8mb4’ => false

in config.php to avoid the trouble that 4byte support seems to cause, but can I suppress the warning about mysql not supporting 4byte characters some how?