Re: expect header, clarification of status

Stefan Eissing <stefan.eissing@greenbytes.de> writes:

> I'd like to get a clarification of the HTTP/1.1 Expect header (RFC
> 2616, 14.20).  This feature is very useful to authoring clients,
> however it currently causes interoperability problems far
> outweighting the potential benefits.

What problems?
 
> There has been discussion on the http-wg mailing list ([1]) with the
> statement by Roy that 2616 has broken compatibility to 2068.
>
> There is however no clarification in the errata[2].

The discussion you cited was during the development of RFC 2616; the
errata only attempts to cover issues that arose after publication.
 
> The conclusion I draw from the mentioned discussion is that
> a) clients, talking to HTTP/1.1 servers, cannot rely on correct
>      Expect header support, since they may be talking to 2068
>      compliant servers.
> b) Requests which have a body will cause the client to hang
>     on a 2068 server. Unfortunately, using Expect together with
>     PUT is one of the more attractive use cases.

Section 8.2.3 lays out procedures for both client and server that I
believe work for all the combinations of Expect header
support/non-support. 
 
--
Scott Lawrence        
  http://world.std.com/~lawrence/
  Actively seeking work

Received on Tuesday, 28 January 2003 09:39:06 UTC