本节描述了密钥环使用的信息来源。

要查看是否加载了密钥环插件，请检查信息schema PLUGINS 表或使用 SHOW PLUGINS 语句（见第7.6.2节，“获取服务器插件信息”）。例如：

mysql> SELECT PLUGIN_NAME, PLUGIN_STATUS
       FROM INFORMATION_SCHEMA.PLUGINS
       WHERE PLUGIN_NAME LIKE 'keyring%';
+-------------+---------------+
| PLUGIN_NAME | PLUGIN_STATUS |
+-------------+---------------+
| keyring_okv | ACTIVE        |
+-------------+---------------+

要查看存在哪些密钥，请检查性能schema keyring_keys 表：

mysql> SELECT * FROM performance_schema.keyring_keys;
+-----------------------------+--------------+----------------+
| KEY_ID                      | KEY_OWNER    | BACKEND_KEY_ID |
+-----------------------------+--------------+----------------+
| audit_log-20210322T130749-1 |              |                |
| MyKey                       | me@localhost |                |
| YourKey                     | me@localhost |                |
+-----------------------------+--------------+----------------+

要查看是否加载了密钥环组件，请检查性能schema keyring_component_status 表。例如：

mysql> SELECT * FROM performance_schema.keyring_component_status;
+---------------------+-------------------------------------------------+
| STATUS_KEY          | STATUS_VALUE                                    |
+---------------------+-------------------------------------------------+
| Component_name      | component_keyring_file                          |
| Author              | Oracle Corporation                              |
| License             | GPL                                             |
| Implementation_name | component_keyring_file                          |
| Version             | 1.0                                             |
| Component_status    | Active                                          |
| Data_file           | /usr/local/mysql/keyring/component_keyring_file |
| Read_only           | No                                              |
+---------------------+-------------------------------------------------+

一个Component_ status值为Active表示该组件初始化成功。如果组件加载但失败初始化，值为Disabled。