解决方法是修改/etc/mysql/my.cnf,添加以下一行:
set-variable = max_connections=500
或在启动命令中加上参数 max_connections=500
就是修改最大连接数,然后重启mysql.默认的连接数是100,太少了,所以容易出现如题错误.
以下是mysql.com网站的相关说明:
If you get a Too many connections error when you try to connect to the mysqld server, this means that all available connections are in use by other clients.
The number of connections allowed is controlled by the max_connections system variable. Its default value is 100. If you need to support more connections, you should restart mysqld with a larger value for this variable.
mysqld actually allows max_connections+1 clients to connect. The extra connection is reserved for use by accounts that have the SUPER privilege. By granting the SUPER privilege to administrators and not to normal users (who should not need it), an administrator can connect to the server and use SHOW PROCESSLIST to diagnose problems even if the maximum number of unprivileged clients are connected. See Section 13.5.4.19, “SHOW PROCESSLIST Syntax”.
The maximum number of connections MySQL can support depends on the quality of the thread library on a given platform. Linux or Solaris should be able to support 500-1000 simultaneous connections, depending on how much RAM you have and what your clients are doing. Static Linux binaries provided by MySQL AB can support up to 4000 connections.
PS：方法2
还有个办法就是到/usr/local/share/mysql/下面拷贝个配置文件my-large.cnf 到/etc目录下为my.cnf，再改最大连接数可以把mysql发挥到最大性能
/usr/local/share/mysql/
下有三个配置文件
my-large.cnf 大型数据库应用
my-medium.cnf 中型数据库应用
my-small.cnf 小型数据库应用
在选择 my-large.cnf的时候对内存要求比较高
在到webmin中mysql服务器的配置文件中修改mysql的最大连接数到4000就可以完美解决MySQL的“too many connections”错误了；
mysql连接数增加后内存占用也比较严重；
