Re: Expect: 100-continue and proxies

Joe Orton wrote:
> 2616 s8.2.3 first bullet of the requirements for proxies has a MUST 
> requirement that a proxy forwards the Expect header to the next hop.
> 
> Apache httpd complies with this (whether by design or by accident, I'm 
> not sure), though it makes little sense: the proxy is written to read 
> and forward the entire request body without waiting for an interim 
> response from the server.

The proxy doesn't have to wait, because the client which sent Expect
will not send a request body for the proxy to forward, until the
timeout heuristic triggers.  There is no need for another delay from
the proxy.

> Why is a MUST condition for the server to forward the 100-continue 
> expectation appropriate, regardless of how a proxy handles the client's 
> request body?

Because if it does not, there will be no 100 Continue sent to the
client, and the request body will be unnecessarily delayed.

-- Jamie