Re: no_cache tag..

Marc-Adrian Napoli wrote:

> Ahh. So the request comes in, the host->IP conversion isn't in Squid's DNS
> cache, so my no_cache ACL on the IP address is ignored because the hostname
> rather than the IP address is used correct?

Correct.

> > acl nowhere dst 0.0.0.0/32
> > http_access deny nowhere
>
> Will I be taking a performance hit on this?

Only on sites not in Squid's DNS cache.

> I can understand how this all works however i'm slightly confused at the
> logic. Even if i don't specify the no_cache for a local webserver, when the
> proxy sees a request for a file on that webserver, shouldn't it hit the
> webserver itself (provided i'm going through the proxy) and then realise
> that the file is different, download it and cache it, serving me the new
> one?

If you have told it so yes.

Caching is about two things:
* Bytes
* Request latency

The byte caching is done by caching the requested contents locally

Latency caching is done by considering the servers response fresh, and
serving it directly from the cache without contacting the origin server
first.

The aggressiveness is tuned by the refresh_pattern settings.

--
Henrik Nordstrom
Squid hacker