Thanks Maxim to taking the time to respond.

> This feature wasn't removed in 5e6142609e48, but rather it was
> changed how things work: instead of doing a full scan over all
> connections on each event loop iteration, nginx now does it only
> once, and also makes sure no new idle connections are added after
> the shutdown signal.
>

I don't fully understand what happens to non-idle keep-alive connections after the shutdown signal is sent.

If I understand correctly, non-idle keep-alive connections will continue to serve requests after a graceful shutdown, until they are terminated by "normal" events, such as:
* connection is closed/terminated by the client
* or by the server, e.g if (r->connection->requests >= clcf->keepalive_requests)
* or if keepalive_timeout is meet
* any other event that would close the connection during normal operation

From reading the code, it looks like this is the expected flow after a graceful shutdown.

I read somewhere that they expected nginx to return "Connection: close" headers to keepalive connections after graceful shutdown signal is sent. But I don't see that is true, and not expected either from reading the code.

Thanks,
Tore