We have a auth module in our code that sends requests to a server and waits for response to approve the request before proceeding to forward the request to a proxy server.

We use the function ngx_http_post_request to post the subrequest. 

As I understand, this function adds the request to a queue which is then processed by ngx_http_run_posted_requests function.

We observe that every single subrequest is sent over a new socket connection. Unfortunately, when we scale to more than 1000 concurrent subrequests, we start seeing socket failures.

Is there a way to specify to this function, to maintain a persistent socket connection with the auth server and reuse the same socket connection for sending multiple subrequests?

Any help is appreciated.