Issue with SSE and fcgiwrap in nginx (RESTCONF)

[Sergey A. Osokin]

Hi Rostyslav,
hope you're doing well.

Thanks for the report!

On Tue, May 13, 2025 at 04:39:20PM -0700, Rostyslav Zalevskyy wrote:
> Hello NGINX team,
> 
> I'm working on a RESTCONF server that streams data via SSE.
> 
> When using Apache2 with mod_fcgid, everything works fine:
> multiple clients can connect to /restconf/streams, and each gets a stream.
> 
> However, when switching to nginx + fcgiwrap, only the first connection
> works.
> All other connections hang or cause nginx to become unresponsive until the
> first SSE stream is closed.

[...]

Is there a chance to build nginx with a debugging log as described on
the following page, https://nginx.org/en/docs/debugging_log.html
and tracing fcgi requests.  Please expect a lot of messages in
the nginx error.log file.

Thank you.

-- 
Sergey A. Osokin