Re: http 1.1. Cache Response Codes...

Have you reviewed RFC 2227 -- "Simple Hit-Metering and Usage-Limiting for
HTTP"? Seems like this RFC is trying to solve your problem. 

Dave Morris

On Thu, 19 Mar 1998, Michael Wexler wrote:

> As a web measurement analyst, one of my worst problems is dealing with
> caching.  Why do we use the code 200 for everything?  Why not design the
> spec in a graduated fashion:
> 
> If browser has url in its local cache, it still sends a get request to the
> server, but an option says "I already have it, just letting you log the
> request". The success code is a 209, "user has non-expired data in cache".
> 
> If a non local cache has the data, same system.  The option can be
> different, and we can even use a different code (210), but for the most
> part, we should just let the 209 mean "cached request".
> 
> This solves many problems:
> 1) path analysis of a user's visit
> 2) advertising requests (not perfectly, given the IAB's recent standards,
> but better than nothing for smaller sites)
> 3) pages per visit calculations are accurate
> 4) this is a minor increase in bandwidth compared to not sending the
> request at all, and is far superior to eliminating caching.