Details
Description
When there are multiple requests to load the same plugin, e.g. both a "plugin_load_add" in the config file and an entry in the mysql.plugin table via "INSTALL PLUGIN", an error message is logged, e.g.:
[ERROR] mariadbd: Plugin 'unix_socket' is already installed.
IMHO this should only be a warning, not an error, as initial loading of the plugin was successful, so no real damage is done by the 2nd loading attempt in most cases.
The exception would be an attempt to load a different version of the same plugin library, but even then a warning should be sufficient IMHO, especially as even the current error output does not terminate server startup.
So both a warning and the current error would go unnoticed if a user doesn't bother to check the error log output, but the current error messages makes the situation sound much more critical than it actually is.
Attachments
Issue Links
- relates to
-
MDEV-32043 mariadb-upgrade should remove mysql.plugin entries for plugins that became bundled
-
- Closed
-
-
-
- Closed
-
-
-
- Closed
-
Activity
This was not so much about error handling on INSTALL PLUGIN, but about a plugin already installed, and so present in the mysql.plugin table, also being loaded via plugin_load_add in the config file(s).
As plugin_load_add happens first when the mysql.plugin table contents are processed later during startup that "Error: plugin already loaded" log line is now raised on every startup, while typically this is not actually much of a problem as trying to load a plugin that is already loaded would just be an idempotent operation.
The server will function the same way regardless of whether a plugin is loaded via plugin_load_add or a prior INSTALL PLUGIN, thus my reasoning that this should merely be a warning, not an error, as server functionality is not impacted.
IF NOT EXISTS would be more consistent with other statements. For example, DROP TABLE fails if the table doesn't exist, it's not a warning because "the table doesn't exist after the statement anyway, no real damage was done"
10.4+:
Can't INSTALL PLUGIN IF NOT EXISTS be used to downgrade any error to a warning?
If a replacement is desired can UNINSTALL PLUGIN IF EXISTS be used before the INSTALL PLUGIN?
The implementation in https://github.com/MariaDB/server/pull/2744 also covers this case.
MariaDB [(none)]> install soname 'locales.so';Query OK, 0 rows affected (0.001 sec)MariaDB [(none)]> shutdown;Query OK, 0 rows affected (0.000 sec)$ sql/mariadbd --no-defaults --datadir=/tmp/${PWD##*/}-datadir --socket=/tmp/${PWD##*/}.sock --plugin-dir=${PWD}/mysql-test/var/plugins/ --verbose --skip-networking --plugin-load-add=locales2023-10-13 10:07:41 0 [Note] Starting MariaDB 10.4.32-MariaDB source revision 3981e9cb385d435d17772c38504982ae9cf8293b as process 393122023-10-13 10:07:41 0 [Note] InnoDB: Using Linux native AIO2023-10-13 10:07:41 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins2023-10-13 10:07:41 0 [Note] InnoDB: Uses event mutexes2023-10-13 10:07:41 0 [Note] InnoDB: Compressed tables use zlib 1.2.132023-10-13 10:07:41 0 [Note] InnoDB: Number of pools: 12023-10-13 10:07:41 0 [Note] InnoDB: Using SSE2 crc32 instructions2023-10-13 10:07:41 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M2023-10-13 10:07:41 0 [Note] InnoDB: Completed initialization of buffer pool2023-10-13 10:07:41 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().2023-10-13 10:07:41 0 [Note] InnoDB: 128 out of 128 rollback segments are active.2023-10-13 10:07:41 0 [Note] InnoDB: Creating shared tablespace for temporary tables2023-10-13 10:07:41 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...2023-10-13 10:07:41 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.2023-10-13 10:07:41 0 [Note] InnoDB: Waiting for purge to start2023-10-13 10:07:41 0 [Note] InnoDB: 10.4.32 started; log sequence number 60961; transaction id 202023-10-13 10:07:41 0 [Note] InnoDB: Loading buffer pool(s) from /tmp/build-mariadb-server-10.4-datadir/ib_buffer_pool2023-10-13 10:07:41 0 [Note] Plugin 'FEEDBACK' is disabled.2023-10-13 10:07:41 0 [Note] InnoDB: Buffer pool(s) load completed at 231013 10:07:412023-10-13 10:07:41 0 [Note] mariadbd: Plugin 'LOCALES' already installed2023-10-13 10:07:41 0 [Note] Reading of all Master_info entries succeeded2023-10-13 10:07:41 0 [Note] Added new Master_info '' to hash table2023-10-13 10:07:41 0 [Note] sql/mariadbd: ready for connections.Version: '10.4.32-MariaDB' socket: '/tmp/build-mariadb-server-10.4.sock' port: 0 Source distribution