- From: A Bagi <ahmed.bagi@virgin.net>
- Date: Sat, 29 May 2004 08:36:07 +0100
- To: "Ian Clelland" <ian@veryfresh.com>, <www-talk@w3.org>
Thank you Ian and sorry PUT! The real world can be harsh! ----- Original Message ----- From: "Ian Clelland" <ian@veryfresh.com> To: <www-talk@w3.org> Cc: "A Bagi" <ahmed.bagi@virgin.net> Sent: Saturday, May 29, 2004 7:56 AM Subject: Re: HTTP 1.1 pipelining > On Fri, May 28, 2004 at 09:14:54PM +0100, A Bagi wrote: > > > > Idempotence: the ability of a Document to be transmitted and accepted more > > than once with the same effect as being transmitted and accepted once. This > > somehow does not mean no side-effects (web applications, GET)! > > Only idempotent requests can be pipelined, such as GET and HEAD requests > > with maximum scucess. POST and PUT are dodgy business!! > > Ahmed Bagi > > Manchester > > If we're going by the way that things are *supposed* to be, then PUT > isn't dodgy at all -- you should be able to submit the same PUT request > a hundred times, and have the outcome be the same as submitting it just > once. From the RFC: > > 9.1.2 Idempotent Methods > > Methods can also have the property of "idempotence" in that (aside > from error or expiration issues) the side-effects of N > 0 > identical requests is the same as for a single request. The > methods GET, HEAD, PUT and DELETE share this property. Also, the > methods OPTIONS and TRACE SHOULD NOT have side effects, and so are > inherently idempotent. > > > Of course, in the real world, things may not be this clean. But, for that > matter, neither are GET requests -- web applications routinely take > parameters from URLs and do horrible, non-idempotent things with them. > So from that perspective, GET is kind of dodgy too. Heck, even HEAD > would have side effects in half of the server-side scripts that I've > seen. > > I don't think it makes sense to leave poor PUT out of a pipelining > application just because some developers might be abusing the HTTP > protocol. There are already worse offences out there, that will break > things much harder, than a non-idempotent PUT or two. > > > Ian Clelland > <ian@veryfresh.com> >
Received on Saturday, 29 May 2004 03:38:09 UTC