mysql数据库查看连接数、并发数相关信息

小渣渣

首先，附上本文所用的工具，由于，我是远程服务器，所以，无法安装一些数据库的查询工具，所以，只能用自己写的通用查询软件了，如下：

.net/c# 通用数据库查询工具助手[附源码]
http://www.itsvse.com/thread-4201-1-1.html
(出处: 架构师_程序员)

1.mysql> show status like 'Threads%';

[{"Variable_name":"Threads_cached","Value":"0"},{"Variable_name":"Threads_connected","Value":"101"},{"Variable_name":"Threads_created","Value":"119"},{"Variable_name":"Threads_running","Value":"2"}]

Threads_connected #这个数值指的是打开的连接数
Threads_running   #这个数值指的是激活的连接数，这个数值一般远低于connected数值
Threads_connected 跟show processlist结果相同，表示当前连接数。准确的来说，Threads_running是代表当前并发数


2.mysql> show variables like '%max_connections%';

[{"Variable_name":"max_connections","Value":"151"}]

这是是查询数据库当前设置的最大连接数

可以在/etc/my.cnf里面设置数据库的最大连接数
[mysqld]
max_connections = 1000
max_connections 参数可以用于控制数据库的最大连接数：


3.mysql> show variables like '%connect%';

[{"Variable_name":"character_set_connection","Value":"utf8"},{"Variable_name":"collation_connection","Value":"utf8_general_ci"},{"Variable_name":"connect_timeout","Value":"10"},{"Variable_name":"disconnect_on_expired_password","Value":"ON"},{"Variable_name":"init_connect","Value":""},{"Variable_name":"max_connect_errors","Value":"100"},{"Variable_name":"max_connections","Value":"151"},{"Variable_name":"max_user_connections","Value":"0"},{"Variable_name":"performance_schema_session_connect_attrs_size","Value":"512"}]

很多开发人员都会遇见”MySQL: ERROR 1040: Too many connections”的异常情况，造成这种情况的一种原因是访问量过高，MySQL服务器抗不住，这个时候就要考虑增加从服务器分散读压力；另一种原因就是MySQL配置文件中max_connections值过小。

330383477

学习了,谢谢

Arch_shell

感谢分享