1914201 - Consider racing TCP and QUIC connections in order to increase the likelihood of establishing an HTTP/3 connection

Status: NEW

(Core :: Networking, enhancement, P3)

Description

[Andrew Creskey [:acreskey]]

In the absence of details on HTTP/3 support from Alt-Svc headers, HTTPS records, or DNS records, we will currently make new connections over HTTP/2.

This bug is to consider racing the tcp connection against a quic connection.

If the host supported HTTP/3, the connection would benefit from reduces latency due the reduction in round trips.

Comment 1

[Andrew Creskey [:acreskey]]

Lars suggested that this could work well if we race when already have the 0-RTT resumption key.

Comment 2

[Andrew Creskey [:acreskey]]

I put this "time to request start by http protocol version" query for Max and on top-level document loads, the time spent connecting, i.e. up to requestStart is about half on HTTP/3 compared to HTTP/2 (~67ms over HTTP/3 vs ~133ms over HTTP/2).

Comment 3

[Lars Eggert [:lars]]

This bug is part of happy eyeballs v3. Do we have a meta-bug for that?