Re: (POST) new multi-phase and security
Paul Burchard (burchard@cs.princeton.edu)
Thu, 9 May 96 02:17:10 -0400
[continued from a private discussion of the security implications
of the automatic retry in multi-phase POST...]
Jeffrey Mogul <mogul@pa.dec.com> writes:
> The problem is that if you insist on perfect
> failure-atomicity, you need an end-to-end "commit" mechanism.
[...]
> HTTP operates at least one level too low for that
Yes, that's what is troubling me.
For that reason, I don't think HTTP agents should make any
*automatic* retry decisions for POST, a method which can initiate
arbitrary state changes. You are really inventing a completely new
method, with dramatically different semantics. Call the new method
something else (maybe REPOST?), and let it compete side-by-side with
POST.
In constrast, retry makes much more sense for a method like PUT,
which is in principle idempotent.
> You should also note that the two-phase mechanism is
> entirely at the option of the server.
But at great cost in performance (compared to HTTP/1.0). If a full
wait is the only way to get standard POST semantics in HTTP/1.1,
then my objections re the previous multi-phase draft still stand.
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Paul Burchard <burchard@cs.princeton.edu>
``I'm still learning how to count backwards from infinity...''
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