- From: Jeffrey Mogul <mogul@pa.dec.com>
- Date: Mon, 13 Nov 95 19:13:44 PST
- To: Shel Kaphan <sjk@amazon.com>
- Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
(optional) (3) we extend the set of headers to include the
generalization "validator" which might be used to contain (e.g.) a
date, filesize, hash, checksum, or random number chosen by the server
as pertaining to a unique version of the document, and allow
"validator=<xxxxx>" to appear as a header in server responses as well
as in this header.
As much as it pains me to disagree with someone who is trying to
agree with me ...
The most important feature of a cache-validator is that it is
100.00000000% opaque to clients and caches. Checksums aren't
opaque; dates aren't opaque; hashes aren't opaque.
If the client or cache is able to do anything with the validator
besides send it back to the server, then it won't work. Which
is to say that some creative but misguided programmer will try
to use it in a way that will, sooner or later, make us all unhappy.
-Jeff
Received on Monday, 13 November 1995 19:59:04 UTC