[squid-users] Squid4 has extremely low hit ratio due to lacks of ignore-no-cache

[Amos Jeffries]

On 26/10/2015 9:53 a.m., Yuri Voinov wrote:
> 
> I can not understand why so much dropped for caching of https.

I dont understand what you mean by that.

You started caching HTTPS and ratio dropped?


HTTPS is less than 30% of total traffic. But;

* has a higher proportion of Cache-Control: private or no-store
messages, and

* the store entries for URI with http:// and https:// are different
objects even if the rest of the URI is identical.

* has a larger amount of Chrome 'sdch' encoding requests.

Any one of the above can cause more MISS by increasing the churn of
non-cacheable content. The wider object space is also trying to fit into
the same cache space/capacity, reducing the time any http:// or https://
object will be cached.
 Don't expect HIT rates for HTTP+HTTPS caching to be the same as for
HTTP-only caching. You likely need to re-calculate all your tuning.

Amos