[#MDEV-21873] 10.2 to 10.3 upgrade doesn't remove semi-sync reference from mysql.plugin table

I noticed that upgrade from 10.2 -> 10.3 doesn't remove semi-sync reference from mysql.plugin table. As per documentation:

In MariaDB 10.3.3 and later, the Semisynchronous Replication feature is built into MariaDB server and is no longer provided by a plugin. This means that installing the plugin is not supported on those versions. In MariaDB 10.3.3 and later, you can skip right to Enabling Semisynchronous Replication.

So, when Semisynchronous is already part of server then should be removed when upgrade is done to 10.3. It should be handled part of server or mysql_upgrade.

Welcome to the MariaDB monitor.  Commands end with ; or \g.

Your MariaDB connection id is 9

Server version: 10.2.31-MariaDB-log MariaDB Server

MariaDB [(none)]> INSTALL SONAME 'semisync_master';

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> INSTALL SONAME 'semisync_slave';

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SELECT * FROM mysql.plugin;

+----------------------+--------------------+

| name                 | dl                 |

+----------------------+--------------------+

| rpl_semi_sync_master | semisync_master.so |

| rpl_semi_sync_slave  | semisync_slave.so  |

+----------------------+--------------------+

From here, I tried to upgrade from 10.2 to 10.3

# rpm -qa | egrep -i "mysql|mariadb"

MariaDB-common-10.3.22-1.el7.centos.x86_64

MariaDB-backup-10.3.22-1.el7.centos.x86_64

MariaDB-client-10.3.22-1.el7.centos.x86_64

MariaDB-server-10.3.22-1.el7.centos.x86_64

MariaDB-compat-10.2.31-1.el7.centos.x86_64

MariaDB-shared-10.3.22-1.el7.centos.x86_64

Welcome to the MariaDB monitor.  Commands end with ; or \g.

Your MariaDB connection id is 10

Server version: 10.3.22-MariaDB-log MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> SELECT * FROM mysql.plugin;

+-----------------------+--------------------------+

| name                  | dl                       |

+-----------------------+--------------------------+

| rpl_semi_sync_master  | semisync_master.so       |

| rpl_semi_sync_slave   | semisync_slave.so        |

+-----------------------+--------------------------+

As you can see reference to semi_sync plugins still present in mysql.plugin table after upgrade.

# mysql_upgrade

Phase 1/7: Checking and upgrading mysql database

Processing databases

mysql

mysql.column_stats                                 OK

mysql.columns_priv                                 OK

mysql.db                                           OK

mysql.event                                        OK

mysql.func                                         OK

mysql.gtid_slave_pos                               OK

mysql.help_category                                OK

mysql.help_keyword                                 OK

mysql.help_relation                                OK

mysql.help_topic                                   OK

mysql.host                                         OK

mysql.index_stats                                  OK

mysql.innodb_index_stats                           OK

mysql.innodb_table_stats                           OK

mysql.plugin                                       OK

mysql.proc                                         OK

mysql.procs_priv                                   OK

mysql.proxies_priv                                 OK

mysql.roles_mapping                                OK

mysql.servers                                      OK

mysql.table_stats                                  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

Phase 2/7: Installing used storage engines... Skipped

Phase 3/7: Fixing views

Phase 4/7: Running 'mysql_fix_privilege_tables'

Phase 5/7: Fixing table and database names

Phase 6/7: Checking and upgrading tables

Processing databases

information_schema

performance_schema

test

Phase 7/7: Running 'FLUSH PRIVILEGES'

OK

MariaDB [(none)]> SELECT * FROM mysql.plugin;

+-----------------------+--------------------------+

| name                  | dl                       |

+-----------------------+--------------------------+

| rpl_semi_sync_master  | semisync_master.so       |

| rpl_semi_sync_slave   | semisync_slave.so        |

+-----------------------+--------------------------+

[MDEV-21873] 10.2 to 10.3 upgrade doesn't remove semi-sync reference from mysql.plugin table Created: 2020-03-04 Updated: 2022-04-09 Resolved: 2022-03-25
Status:	Closed
Project:	MariaDB Server
Component/s:	Plugins, Scripts & Clients
Affects Version/s:	10.3, 10.4
Fix Version/s:	10.3.35, 10.4.25

[MDEV-21873] 10.2 to 10.3 upgrade doesn't remove semi-sync reference from mysql.plugin table Created: 2020-03-04 Updated: 2022-04-09 Resolved: 2022-03-25