On 8/04/2014 12:54 p.m., Sylvio Cesar wrote: > Amos, > > I have configured squid.conf > > request_header_access Vary deny all > > put the squid ignores this and still appears the Vary: Accept-Encoding > Is there a way to delete the row of squid Vary: Accept-Encoding? No. That will screw up HTTP. >From the IETF draft which is about to become the new HTTP/1.1 RFC standard (<http://tools.ietf.org/html/draft-ietf-httpbis-p2-semantics-26#section-7.1.4>) " An origin server might send Vary with a list of fields for two purposes: 1. To inform cache recipients that they MUST NOT use this response to satisfy a later request unless the later request has the same values for the listed fields as the original request (Section 4.1 of [Part6]). In other words, Vary expands the cache key required to match a new request to the stored cache entry. " No matter what is done when communicating with the server it is the *received* header from clients which Squid is required to use for cache lookups. ==> Mangling the headers delivered to the server (and thus the ones used to store the object) will only increase the amount of MISS happening on Vary. As later client requests with even the same headers as current client request will not match the headers sent to the server. The best you can do is ensure that the server sees the headers Squid received from the client as accurately as possible (for at least the set mentioned in Vary). Future requests from the same client or others with the same UA and encoding can then HIT. Remember: there is *never* a guarantee of a HIT in real traffic. Caching is a "best effort" mechanism. Amos
