5.5.3.2 Thread Pool Installation

This section describes how to install MySQL Enterprise Thread Pool. For general information about installing plugins, see Section 5.5.1, “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, configure the plugin directory location by setting the value of plugin_dir at server startup.

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

To enable thread pool capability, load the plugins to be used by starting the server with the --plugin-load-add option. For example, if you name only the plugin library file, the server loads all plugins that it contains (that is, the thread pool plugin and all the INFORMATION_SCHEMA tables). To do this, put these lines in the server my.cnf file, adjusting the .so suffix for your platform as necessary:

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

That is equivalent to loading all thread pool plugins by naming them individually:

[mysqld]
plugin-load-add=thread_pool=thread_pool.so
plugin-load-add=tp_thread_state=thread_pool.so
plugin-load-add=tp_thread_group_state=thread_pool.so
plugin-load-add=tp_thread_group_stats=thread_pool.so

If desired, you can load individual plugins from the library file. To load the thread pool plugin but not the INFORMATION_SCHEMA tables, use an option like this:

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

To load the thread pool plugin and only the TP_THREAD_STATE INFORMATION_SCHEMA table, use options like this:

[mysqld]
plugin-load-add=thread_pool=thread_pool.so
plugin-load-add=tp_thread_state=thread_pool.so

Note

If you do not load all the INFORMATION_SCHEMA tables, some or all MySQL Enterprise Monitor thread pool graphs are empty.

To verify plugin installation, examine the Information Schema PLUGINS table or use the SHOW PLUGINS statement (see Section 5.5.2, “Obtaining Server Plugin Information”). For example:

mysql> SELECT PLUGIN_NAME, PLUGIN_STATUS
       FROM INFORMATION_SCHEMA.PLUGINS
       WHERE PLUGIN_NAME LIKE 'thread%' OR PLUGIN_NAME LIKE 'tp%';
+-----------------------+---------------+
| PLUGIN_NAME           | PLUGIN_STATUS |
+-----------------------+---------------+
| thread_pool           | ACTIVE        |
| TP_THREAD_STATE       | ACTIVE        |
| TP_THREAD_GROUP_STATE | ACTIVE        |
| TP_THREAD_GROUP_STATS | ACTIVE        |
+-----------------------+---------------+

If the server loads the thread pool plugin successfully, it sets the thread_handling system variable to loaded-dynamically.

If a plugin fails to initialize, check the server error log for diagnostic messages.