[Web-SIG] expect/continue

Mark Nottingham mnot at mnot.net
Fri Aug 27 01:03:36 CEST 2004


I like the Expect/Continue langauge in the latest draft -- thanks!

One thing; the first bullet point gives servers and gateways the option 
of "Reject[ing] all client requests containing an Expect: 100-continue 
header with a '417 Expectation failed' error."

This doesn't seem like a good thing to allow, because it makes server 
implementations that take this path reject ALL requests that use 
expect/continue, with no recourse. The intent of Expect/Continue is 
that it should fall back to normal operation (the request gets sent and 
processed) unless it is explicitly rejected.

So, I think this option should be removed. I can see some scenarios 
where the server can and will be configured to reject all requests over 
a certain size, etc. but rejecting all requests that use this mechanism 
indiscriminately doesn't seem to fall into that case. If an 
implementation doesn't want to deal with expect/continue at all, it has 
two choices;

1) don't claim to be HTTP/1.1 conformant

2) wait until the client decides you don't support expect/continue, and 
sends the request body (this is suboptimal, for obvious reasons).


Mark Nottingham     http://www.mnot.net/

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