On 23/05/2013 11:37, Igor Galić wrote: > > > ----- Original Message ----- >> >> >> Am 23.05.2013 09:18, schrieb 오재경: >>> As you know, the values of ETag are different depending on origin >>> server even though contents are same. >> >> why should this be the case? > > This has historical (or as I like to call it hysterical) reasons - on > Apache httpd anyways: > > up until 2.2 FileETag used to default to All: > http://httpd.apache.org/docs/2.2/mod/core.html#fileetag > > All includes: Size, MTime, and Inode. INode is pretty much guaranteed > to NOT be the same accross nodes. > > starting httpd 2.3.14, we made sure this is no longer the > case: http://httpd.apache.org/docs/2.4/mod/core.html#fileetag > > The default is now Size and MTime >
Yeah, but not everyone will run httpd, and not all httpd users are on 2.4, so the point should still stand. Spec-wise, there's no guarantee that 2 HTTP servers will calculate the same ETag for a single file. Issac
