Too many connections 要点：

ERROR 1040 (08004): Too many connectionsMYSQL必读

解决办法,这也是centos7下修改mysql连接数的做法：

1)临时修改

MariaDB [(none)]> show variables like "max_connections";

+-----------------+-------+

| Variable_name | Value |

+-----------------+-------+

| max_connections | 214 |

+-----------------+-------+

1 row in set (0.00 sec)

MariaDB [(none)]> set GLOBAL max_connections=1000;

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> show variables like "max_connections";

+-----------------+-------+

| Variable_name | Value |

+-----------------+-------+

| max_connections | 1000 |

+-----------------+-------+

1 row in set (0.00 sec)

　　

2)永久修改：

配置/etc/my.cnf

　　

[mysqld]新添加一行如下参数：

max_connections=1000

　　

重启mariadb服务,再次查看mariadb数据库最大连接数,可以看到最大连接数是214,并非我们设置的1000.

MariaDB [(none)]> show variables like 'max_connections';

+-----------------+-------+

| Variable_name | Value |

+-----------------+-------+

| max_connections | 214 |

+-----------------+-------+

　　

这是由于mariadb有默认打开文件数限制.可以通过配置/usr/lib/systemd/system/mariadb.service来调大打开文件数目.MYSQL必读

配置/usr/lib/systemd/system/mariadb.service

MYSQL必读

[Service]新添加两行如下参数：

LimitNOFILE=10000

LimitNPROC=10000

　　

重新加载系统服务,并重启mariadb服务

systemctl --system daemon-reload

systemctl restart mariadb.service

　　

再次查看mariadb数据库最大连接数,可以看到最大连接数已经是1000

MariaDB [(none)]> show variables like 'max_connections';

+-----------------+-------+

| Variable_name | Value |

+-----------------+-------+

| max_connections | 1000 |

+-----------------+-------+