Cowboy closes a connection after responding with 503?

[akanashin]

Hi!

I'm seeing a strange situation here.
I need to respond with 503 Service Unavailable and Retry-After to perform something before client returns. And it seems that the connection gets unexpectedly closed. I'm getting this message from the client:

HTTPConnectionPool(host='127.0.0.1', port=8080): Read timed out.
(For HTTPS the message looks similarly).

When I'm responding with 401 in the same situation the client does not report this.
My code only changes respond code and Headers/Body. Nothing but it.

I'm not very familiar with the client code. This is python project nmos-testing-tool.

Now I'm unable to find anything related to Cowboy would close the connection in such a case. Thus the question: does it do it? Or I'm observing something different here?

Thanks

[essen]

It doesn't but if your retry-after is large enough the connection may be dropped by one of the timeouts. You can increase the idle_timeout to avoid that.

[akanashin]

Thanks! I will check this for sure.
Now, is there any way to check state of a connection if I'm only using Cowboy as a HTTP server (providing a Dispath map and using cowboy:start_clear)?

[essen]

Simplest is probably to use dbg to trace events. There are various guides available online but something like this should get you started:

dbg:tracer().
dbg:tpl(cowboy_stream_h, []).
dbg:tpl(cowboy_http, []).
dbg:p(all, c).