[EMAIL PROTECTED] wrote:
I thought you were referring to the scheme you proposed in an earlier email where you WERE planning on doing just that...
Once again, I probably was just uncelar or, frankly, said what I didn't mean :)
Take your logic just a tiny step farther.
I you know EVERYTHING about the data... then you CERTAINLY can/would.
In the situations in which we are speaking of currently, the "origin" and the "cache" may indeed be the same box, or one controlled by the same person. In these situations, you should be able to "influence" the Vary'ing scheme.
Like I said, if you know alot about the content, then you know when to REALLY vary and when to "cheat."
When does a response REALLY (actually) Vary and why should you have to store tons and tons of responses all the time?
True. But you have to make the decision of which version to server based purely on the clients request headers.If you MD5 and/or hard-CRC/cheksum the actual BODY DATA of a response and it does not differ one iota from another (earlier) non-expired response to a request for the same URI... then those 2 'responses' DO NOT VARY.
Even if you get 25,000 different 'User-Agents' asking for the same URI... there will most probably only be a small sub-set of actual RESPONSES coming from the COS.
Correct. This how using SetEnvIf to set an environment variable is a better solution than varying on the "string value" of the User-Agent header.
Topic for discussion? Kindling for a flame ware? Not sure... but you raise an interesting question.
Yes :)
Only the most recent versions of SQUID make any attempt
to support 'Vary:' at all.
We know a few things about squid. And what you say is true. It supports it "well enough" for what we use it for. We serve 2 billion + hits a day using Squid.
Note: this does not imply that CNN or Time Warner in any way endorse squid or any mentioned product.
Yes. But in the case of caching you own content, as long as you leave the Vary headers in tact, it shouldn't matter how you actually handle the Vary.
It should remain THEIR choice, no matter what.
-- Brian Akins Senior Systems Engineer CNN Internet Technologies