Re: New Version Notification for draft-thomson-http-replay-00.txt

On Tue, Jul 25, 2017 at 03:55:17PM +1000, Martin Thomson wrote:
> On 25 July 2017 at 15:22, Willy Tarreau <w@1wt.eu> wrote:
> >> There's probably some way that we can describe rules for retrying at the
> >> intermediary.  It does save a round trip between the user agent and
> >> intermediary, and there is some potential value in having intermediaries
> >> repair things.  But we lose some of the nicer end-to-end properties by
> >> doing so.
> >
> > In fact I think there are some situations where it can safely be done,
> > specifically if the request was received as 1-RTT, or if the handshake
> > was completed in the mean time because it then becomes equivalent.
> 
> Those are probably both cases where retries are inappropriate.
> 
> If the request arrives over 1-RTT, the intermediary probably shouldn't
> be using 0-RTT.


I see your point. Some users may consider the intermediary as part of the
client, extending it to completely deal with retries, hiding them from the
client.

> If the connection was completed since the 0-RTT attempt was made, that
> doesn't mean that it wasn't replayed already elsewhere.

But that's the same if the client retries, which is why clients are encouraged
not to take too much risk by sending only apparently idempotent methods over
0-RTT.

Willy

Received on Tuesday, 25 July 2017 06:27:00 UTC