x/net/http2: if http1 Server's keep-alives are disabled, only do one request

[bradfitz]

As part of #9478, I noticed the HTTP/2 server doesn't respect SetKeepAlivesEnabled.

Do that.

After the first http2 Server response, check:

func (s *Server) doKeepAlives() bool {

And if it's false, start a graceful GOAWAY shutdown.

/cc @tombergan

[tombergan]

HTTP/2 does not support Connection: keep-alive or Connection: close.

http://httpwg.org/specs/rfc7540.html#rfc.section.8.1.2

HTTP/2 does not use the Connection header field to indicate connection-specific header fields

The HTTP/2 protocol is centered around the idea of multiple requests per connection. If someone wants one request per connection, they should just use HTTP/1. Maybe just update the SetKeepAliveEnabled docs?

[bradfitz]

Yeah, simplest case is just documentation.

Or we could even change the advertised ALPN protos at runtime to exclude "h2" if keep-alives are disabled. But h2 + immediate GOAWAY after first response isn't really worse than h1 + "Connection: close".

[gopherbot]

CL https://golang.org/cl/33153 mentions this issue.

[rsc]

Sounds like there was a decision since there is now a CL. Change to NeedsFix?

[gopherbot]

CL https://golang.org/cl/33231 mentions this issue.