can not disable proxy_request_buffering causing upload problem

[darkclip]

I have a backend app that needs to directly handle large file upload post requests.
As far as I know, the only parameter that matters is to turn off proxy_request_buffering, and that's what I've always been doing.
However, it seems no matter where I set the param, npmplus always buffers the client request body. And that cause the large upload fails.
I've also tried lots of other configs seem no effect. (disable http2 http3 modsec etc.) And I also tested on a different backend (sftpgo), the same result.
It seems this issue only happens with npmplus. Any ideas?

[Zoey2936]

How do you know that it is still bufferd?

[darkclip]

For starters, because client_body_buffer_size is set to a relatively small size, a warning of a client request body is buffered to a temporary file keeps popping up.
Second, the backend couldn't receive the post request until the entire file is sent.

[darkclip]

for anyone who has the same problem, the cause of it is due to http 2.0 and above support.
because from nginx to backend, the max proxy version is 1.1, when http/2 request coming in to nginx, nginx will aways buffer request regardless of proxy_request_buffering setting.

[Zoey2936]

do you use crowdsec?

[darkclip]

yes, but I don't think crowdsec is relevant.
upon further investigation, for nginx it's not possible to use different protocols for the same port.
so once set listen for HTTP2 or QUIC for default port, it seems not possible to turn off proxy_request_buffering for any server.

[Zoey2936]

It is relevant, because if you disable it, it should works. At least for proxy_buffering, but it should also fix proxy_request_buffering

[darkclip]

tried your suggestion, no luck. -_-