Mysql 连接数以及状态学习笔记

1. 查看最大连接数

show variables like '%max_connections%';

2. 查看线程相关变量

show status where `variable_name` like 'Threads_%';

结果显示

+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| Threads_cached    | 144   |
| Threads_connected | 17    |  //打开的连接数，与show processlist 可能一致，也有可能有差，具体要看你用户的权限，show processlist查看的是与你用户相关的
| Threads_created   | 163   |
| Threads_running   | 9     |  //活跃的连接数，某种程度说也就是当前的并发数
+-------------------+-------+

3. 状态

mysqladmin -u ${user} -h ${host} -p${password} status

结果显示：

Uptime: 11660303  Threads: 28  Questions: 444829773  Slow queries: 774  Opens: 25512  Flush tables: 144  Open tables: 1995  Queries per second avg: 38.149

查看其它状态

mysqladmin -u ${user} -h ${host} -p${password} extended-status