- From: Werner Baumann <werner.baumann@onlinehome.de>
- Date: Fri, 02 May 2008 19:37:47 +0200
- To: ietf-http-wg@w3.org
I want to remind of how Apache and IIS use weak etags: They create weak etags when the time of the request is within the same second as the last modified date of the resource. This weak etags simple mean: - if the etag matches, the entity is most probably unchanged, but there is a small chance, that it changed. - if the entity changed, it may have changed into anything; there is absolutely no check for anything like semantic equivalence. From this common use of weak etags, it makes sense to not allow weak etags in PUT (lost update problem), but to allow it in full body GET (in case the entity changed, the damage is usually small). The spec is inconsistent in mixing up this kind of "unreliable" etag with semantic equivalence. The issue may be resolved to either side. But of course, associating "semantic equivalence" with weak etags will render most servers none compliant. Werner
Received on Friday, 2 May 2008 17:38:36 UTC