Re: 1xx response semantics

[Willy Tarreau <[e-mail]>]

Hi Mark,

On Tue, Jul 05, 2011 at 09:41:59AM +1000, Mark Nottingham wrote:
> One (of many) of the issues with 1xx responses is that people don't know how to surface two responses to one request in APIs and tools. 
> 
> I think we could make things a bit easier for folks if we stated that the headers in a 1xx response are semantically not significant; i.e., it's OK for APIs, etc. to drop them on the floor, because the only information is in the status code.
> 
> This would mean that people shouldn't put headers on a 1xx response and expect applications to see them -- which I think is already the case today.

It's not exact because of 101 which should contain at least Upgrade and
Connection: Upgrade. In fact, 101 is a final status while 100 is an
intermediate one.

Maybe we should indicate that "headers are not significant on intermediate
responses such as 1xx, and are only meaningful on final responses such as
all other ones, including 101" ?

Willy