- From: Mark Nottingham <mnot@mnot.net>
- Date: Thu, 18 Jun 2009 10:48:31 +1000
- To: "Yngve N. Pettersen (Developer Opera Software ASA)" <yngve@opera.com>
- Cc: "ietf-http-wg@w3.org Group" <ietf-http-wg@w3.org>, Henrik Nordstrom <henrik@henriknordstrom.net>
Exactly. This is a problem that can be addressed by evangelisation and education. E.g., Curl until quite recently emitted Pragma: no-cache, but as of this January (IIRC) this changed. On 17/06/2009, at 7:12 AM, Henrik Nordstrom wrote: > mån 2009-06-15 klockan 16:42 +0200 skrev Yngve Nysaeter Pettersen: > >> As I said above: If they made the choice. In many cases I don't >> think they >> did more than select a development environment that made the choice >> for >> them, based on what is supposed to provide a "revalidate each time >> the >> user clicks on a link to this document"-functionality, that is, the >> same >> as "Cache-Control: max-age=0" and "no-cache". > > All environments I have seen support setting these kind of things if > you > care about them, and emit a default "do not cahe this response" header > if the author / site developer using such environment don't care. Most > people who don't care simply do not know, and quite happily try to > accomodate for caching when they learn what it is. > > Blaiming the dev environment for emitting a safe low-performance > default > cache profile won't get us very far, neither is trying to work around > this in the cache layer. This situation will persist, and any > changes we > make to the protocol will only get reflected in those dev environments > using the new names, until the content/site developers gets their acts > together. > > This is a case of careless developers making their sites slower than > they need to be, not a specifacion fault, and not causing an error of > any kind, just slow performance due to content author/developer > ignorance, just as the 100 other asoects which makes web content > delivery slower than it need to be and is as frequently ignored by > content developers/authors. > > Regarding some of the big sites using this that can only be assumed to > be their choice, quite likely due to browser bugs in dealing with > no-cache or Vary:. Many of these sites uses Cookie based logins or > user > identification, with a farily large userbase of "known users" who do > get > slightly modified content compared to anonymous readers. > > Regards > Henrik > -- Mark Nottingham http://www.mnot.net/
Received on Thursday, 18 June 2009 00:49:08 UTC