系统表介绍
socket_instances 表提供了 当前MySQL服务器链接的实时快照。 表中每一行代表一个TCP/IP or Unix socket 文件连接 。
| 列名 | 含义 |
|---|---|
| EVENT_NAME | 事件名称 |
| OBJECT_INSTANCE_BEGIN | 内存中唯一地址 |
| THREAD_ID | 内部线程编号 |
| SOCKET_ID | SOCKET 句柄 |
| IP | 客户端IP地址 |
| PORT | 端口号 |
| STATE | 状态 （IDLE/ ACTIVE） |
实例
mysql> SELECT * FROM performance_schema.socket_instances
-> ;
+----------------------------------------+-----------------------+-----------+-----------+----+------+--------+
| EVENT_NAME | OBJECT_INSTANCE_BEGIN | THREAD_ID | SOCKET_ID | IP | PORT | STATE |
+----------------------------------------+-----------------------+-----------+-----------+----+------+--------+
| wait/io/socket/sql/server_tcpip_socket | 44603392 | 1 | 27 | :: | 3306 | ACTIVE |
| wait/io/socket/sql/server_unix_socket | 44603712 | 1 | 34 | | 0 | ACTIVE |
| wait/io/socket/sql/client_connection | 44625152 | 346 | 66 | | 0 | ACTIVE |
+----------------------------------------+-----------------------+-----------+-----------+----+------+--------+
3 rows in set (0.00 sec)