max_connections 与 max_used_connections --ERROR 1040: Too many connections

mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 151   |
+-----------------+-------+
1 row in set (0.03 sec)

mysql> show global status like 'max_used_connections';
+----------------------+-------+
| Variable_name        | Value |
+----------------------+-------+
| Max_used_connections | 1     |
+----------------------+-------+
1 row in set (0.19 sec)

secureCRT在打开一个窗口 mysql -uroot -p 登陆

mysql> show global status like 'max_used_connections';
+----------------------+-------+
| Variable_name        | Value |
+----------------------+-------+
| Max_used_connections | 2     |
+----------------------+-------+
1 row in set (0.01 sec)

MySQL比较理想的最大连接数计算方式为：

 

1	max_used_connections / max_connections * 100% ≈ 85%