Specify when and how to request SVCB/HTTP RRs

[tfpauly]

My initial proposal here is:

• Request HTTPS records for any case where the port is 443 or 80, or the URL has a scheme of http:// or https://
• Request the HTTPS record in parallel with A and AAAA

[DavidSchinazi]

• Request HTTPS records for any case where the port is 443 or 80

This part I'm not convinced about. It's possible to run non-HTTP(S) protocols on those ports

or the URL has a scheme of http:// or https://

This part I agree with. Though I'd phrase it as "application will use HTTP(S)" instead of mentioning the URL - semantically you can create an HTTP connection without having an URL in mind.

• Request the HTTPS record in parallel with A and AAAA

Definitely agree

[tfpauly]

(This ends up updating the current section 4)

[bashi]

This part I agree with. Though I'd phrase it as "application will use HTTP(S)" instead of mentioning the URL - semantically you can create an HTTP connection without having an URL in mind.

"application will use HTTP(S) or WebSocket" (ws:// and wss://) ?

[tfpauly]

Yes, web socket too

[ericorth]

For context, Chrome queries HTTPS whenever the request reaches our DNS stack tagged with a scheme of "http", "https", "ws", or "wss" (but websocket requests are typically internally converted to http/https-schemed URLs before the request gets there anyway). Some requests, e.g. for proxy servers, never have their scheme tagged with the request to the DNS stack and never query HTTPS. I keep meaning to fix that some day.