Re: Problem with cached entries w/ETag and request without If-None-Match header

Selecting request headers are specified by Vary; If-None-Match is a
conditional request header.

Cheers,

On 16/06/2009, at 12:44 AM, Jason Noble wrote:

> From RFC 2616 13.6:
> ...
> When the cache receives a subsequent request whose Request-URI
> specifies one or
> more cache entries including a Vary header field, the cache MUST NOT
> use such a
> cache entry to construct a response to the new request unless all of
> the
> selecting request-headers present in the new request match the
> corresponding
> stored request-headers in the original request. ...
>
>
> For the case in question, all selecting request headers do not match
> the stored request headers. Therefore, the cache must not use the
> stored entry to construct a response.
>
> --Jason
>
> Mark Nottingham wrote:
>> What requirement in RFC2616 does this violate?
>>
>> On 13/06/2009, at 3:02 AM, Jason Noble wrote:
>>
>>> I recently ran into a bug on Squid 2.7 regarding cached content
>>> with ETags. Currently, if all cached entries for a URL include
>>> ETags, and a request is received for said URL with no If-None-
>>> Match header, Squid will serve a cached entry. This behavior does
>>> not follow RFC 2616. I have attached a patch that prevents Squid
>>> from serving the cached entries in said case here: http://www.squid-cache.org/bugs/show_bug.cgi?id=2677
>>>
>>> I would appreciate any feedback regarding this patch.
>>>
>>> Thanks,
>>> Jason
>>
>> --
>> Mark Nottingham mnot_at_yahoo-inc.com
>>
>>

--
Mark Nottingham       mnot_at_yahoo-inc.com