- From: Koen Holtman <koen@win.tue.nl>
- Date: Tue, 29 Jun 1999 13:37:54 +0200 (MET DST)
- To: liberte@w3.org (Daniel LaLiberte)
- Cc: mcmanus@appliedtheory.com, danielh@econ.ag.gov, www-talk@w3.org
Daniel LaLiberte: > [...hit metering..] >One workaround might be to send out all documents with the following header: > > Cache-Control: must-revalidate, maxage=0 Picking a nit: it is max-age=0, not maxage=0. > >Then compliant clients should always make If-modified-since requests to >the origin server. I'm using this at hypernews.org, but not for hit >counting - just because any message page might have a new reply. Note that 'must-revalidate' is the strongest HTTP/1.1 revalidation directive you can use on a proxy. It is meant to be used primarily if a failure to revalidate (for example because the link from the cache to the server is down) gives incorrect application behavior. A friendlier way of cache-busting to do hit counting would be to use max-age=0 only, or s-maxage=0 (see rfc2616). And as always, leave out a the Last-Modified header or add an Expires to deal with legacy HTTP/1.0 caches. >But IE 5 might have a bug regarding this must-revalidate feature: it >doesn't redisplay a page when you revisit it from your history with Back >and Forward keys until you hit enter in the location field, or something >like that. That is not a bug in IE5, that is the exact behavior required by the standard. Back is supposed to show the old page you have seen before, not fetch a new copy. See for example section 13.13 of rfc2616. >Daniel LaLiberte >liberte@w3.org Koen.
Received on Tuesday, 29 June 1999 07:38:01 UTC