Can nginx has the capability to dynamically limit the connections when the upstream server has full load

[Valentin V. Bartenev]

On Friday 19 August 2016 09:25:46 tjlp at sina.com wrote:
>  Hi,
> 
> I have a scenario: my backend servers provide URL to query whether this sever can accept new connections (the http response body is "true" or "false"). This server also has configuration for the max allowed session. Now I want to use Nginx as load balancer. Does Nginx provide such kind of load balancing configuration: when a backend server can't accept new connection, the new session won't be created for this full server?
> 

Just curious, why is it done this way?

If your server doesn't want to accept new connections,
then why it doesn't just reject them with some error code?

The commercial version of nginx is able to query such kind of URL.
See for details: http://nginx.org/r/health_check

  wbr, Valentin V. Bartenev