Re: does no-store request invalidate?

My reading is that a no-store request header applies to that request  
only; i.e., it's control information specific to that client, at the  
time it made that request. Otherwise, a malicious client could  
effectively invalidate any cache entry it chose to.

Cheers,

On 26/07/2005, at 9:53 AM, Alex Rousskov wrote:

>
> Hello,
>
>     Responses to HTTP requests with "Cache-control: no-store" are not
> cachable. Recently, we came across a cache that does not cache  
> responses
> to no-store requests but also does not invalidate an older cached  
> entity
> with the same URL. When future requests stop using no-store, the old
> cached entity is served.
>
> For example, the following happens in our test case:
>
>   1. Client requests an entity A without using no-store.
>   2. Cache proxies the transaction and caches the response (entity A).
>
>   3. Client requests the same entity A using "Cache-control: no- 
> store".
>   4. Cache proxies the transaction and does NOT cache the response.
>
>   5. Client requests the same entity A again, without using no-store.
>   6. Cache serves the "old" entity A cached in step #2 above.
>
> Does the cache violate the intent of RFC 2616 in step #6? If yes,  
> should
> that intent be made explicit (I cannot find any explicit rules
> prohibiting the above behavior)?
>
> If no, should the cache check that response in step #4 does not  
> indicate
> that cached entity A is stale? I cannot find explicit rules requiring
> that, but we do have similar rules about 304 and HEAD responses
> invalidating older cached entities.
>
> Thank you,
>
> Alex.
>
>
>
>
>


--
Mark Nottingham     http://www.mnot.net/

Received on Wednesday, 27 July 2005 19:56:16 UTC