Nginx version 1.6, yum install
HTTP {
Limit_conn_zone $binary_remote_addr zone=addr: 10 m;
}

The location/{
Limit_conn addr 1;
}
Add limit parameters, the restart nginx, use ab concurrent test, is invalid, for an IP and no restrictions have been concurrent, change the version is invalid, reference materials including the baidu said m countries is the basic introduction, no explanation, could you tell me who knows nginx limit IP concurrent set do you have any other requirements, why not rev?

And the Module can be ngx_http_limit_conn_module default? Why there is no limit in nginx - V parameter module parameters?