Keepalived Connections Reset after reloading the configuration (HUP Signal)

[Maxim Dounin]

Hello!

On Wed, Oct 07, 2020 at 04:29:50AM -0400, tored wrote:

> I'm looking into the same issue; how to improve graceful shutdown when using
> keep-alive connections.
> 
> It seems nginx at some point had support for doing graceful shutdown (if i
> read the code correctly):
> http://hg.nginx.org/nginx/rev/03f1133f24e8
> 
> But it was removed at a later stage:
> http://hg.nginx.org/nginx/rev/5e6142609e48

You aren't reading the code correctly.

Starting with nginx 0.5.15 (revision 03f1133f24e8), nginx closes 
keepalive connnections when it receives the reconfiguration 
signal.  Quoting CHANGES:

    *) Feature: now the keep-alive connections are closed just after
       receiving the reconfiguration signal.

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.

[...]

-- 
Maxim Dounin
http://mdounin.ru/