MySQL 8.4 Reference Manual Including MySQL NDB Cluster 8.4

7.6.7.1 Installing the Clone Plugin

This section describes how to install and configure the clone plugin. For remote cloning operations, the clone plugin must be installed on the donor and recipient MySQL server instances.

For general information about installing or uninstalling plugins, see Section 7.6.1, “Installing and Uninstalling Plugins”.

To be usable by the server, the plugin library file must be located in the MySQL plugin directory (the directory named by the plugin_dir system variable). If necessary, set the value of plugin_dir at server startup to tell the server the plugin directory location.

The plugin library file base name is mysql_clone.so. The file name suffix differs by platform (for example, .so for Unix and Unix-like systems, .dll for Windows).

To load the plugin at server startup, use the --plugin-load-add option to name the library file that contains it. With this plugin-loading method, the option must be given each time the server starts. For example, put these lines in your my.cnf file, adjusting the plugin library file name extension for your platform as necessary. (The plugin library file name extension depends on your platform. Common suffixes are .so for Unix and Unix-like systems, .dll for Windows.)

[mysqld]
plugin-load-add=mysql_clone.so

After modifying my.cnf, restart the server to cause the new settings to take effect.

Note

The --plugin-load-add option cannot be used to load the clone plugin when restarting the server during an upgrade from a previous MySQL version. In such cases, attempting to restart the server with plugin-load-add=mysql_clone.so raises the error [ERROR] [MY-013238] [Server] Error installing plugin 'clone': Cannot install during upgrade. To keep this from happening, upgrade the server before attempting to start the server with plugin-load-add=mysql_clone.so.

Alternatively, to load the plugin at runtime, use this statement, adjusting the .so suffix for your platform as necessary:

INSTALL PLUGIN clone SONAME 'mysql_clone.so';

INSTALL PLUGIN loads the plugin, and also registers it in the mysql.plugins system table to cause the plugin to be loaded for each subsequent normal server startup without the need for --plugin-load-add.

To verify plugin installation, examine the Information Schema PLUGINS table or use the SHOW PLUGINS statement (see Section 7.6.2, “Obtaining Server Plugin Information”). For example:

mysql> SELECT PLUGIN_NAME, PLUGIN_STATUS
       FROM INFORMATION_SCHEMA.PLUGINS
       WHERE PLUGIN_NAME = 'clone';
+------------------------+---------------+
| PLUGIN_NAME            | PLUGIN_STATUS |
+------------------------+---------------+
| clone                  | ACTIVE        |
+------------------------+---------------+

If the plugin fails to initialize, check the server error log for clone or plugin-related diagnostic messages.

If the plugin has been previously registered with INSTALL PLUGIN or is loaded with --plugin-load-add, you can use the --clone option at server startup to control the plugin activation state. For example, to load the plugin at startup and prevent it from being removed at runtime, use these options:

[mysqld]
plugin-load-add=mysql_clone.so
clone=FORCE_PLUS_PERMANENT

If you want to prevent the server from running without the clone plugin, use --clone with a value of FORCE or FORCE_PLUS_PERMANENT to force server startup to fail if the plugin does not initialize successfully.

For more information about plugin activation states, see Controlling Plugin Activation State.