记录一次mysql连接数最大告警

1、收到告警，mysql连接满了

以下是更改过程，不需要重启mysql，如果永久生效的话需要更改my.cnf文件。

mysql> show variables like '%max_connections%';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 151   |
+-----------------+-------+
1 row in set (0.00 sec)

mysql> set GLOBAL max_connections = 300;
Query OK, 0 rows affected (0.01 sec)

mysql> show variables like '%max_connections%';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 300   |
+-----------------+-------+
1 row in set (0.00 sec)

mysql> quit