Re: [squid-users] questions: cache_dir null & refresh_pattern

mån 2003-02-24 klockan 11.49 skrev alp:
> hi, I have some questions regarding two topics:
>
> 1) i compiled squid with support for cache_dir and used cache_dir null /tmp
> this works fine.
> now, if I use cache_dir null and make some requests, then I get TCP_MEM_HITs
> in access_log. does the cache_dir null directive only means: no caching on
> disk but still in memory???

Yes.

> so in order to cache nothing, I must use a no_cache deny all ???

yes.

> is this right?

yes.

> 2) i have seen, that the usage of refresh_pattern defaults have changed from
> 2.4 to 2.5. but I am not sure if I understand it correctly (henrik also
> answered me something in this stuff):

What changed is that Squid no longer uses the suggested list of
"suitable" refresh patterns if your squid.conf contains none and only
uses the default (which is the same as the '.' refresh pattern in the
suggested list of default patterns).

The actual defaults did not change.

This change was done to make the refresh patterns more consistent as the
list of suggested defaults was only used IFF there was no
refresh_patterns at all. As soon as you defined one refresh pattern this
was what was being used.

In both versions, squid.conf.default contains the exact same list of
suggested refresh_pattern settings, active by deault.

> in 2.4, the three lines (for ftp, gopher and .) are used as default,
> nevertheless they are outcommented or not. right?

Yes and no. The three are only used IFF there is no other
refresh_pattern at all.

> in 2.5, if I outcomment them, they are not used. right?

The default is then used, which "happens" to be the same as the '.'
pattern.

> if so and if i let the outcommented, what happens then to requests? is still
> a default line used (. 0 20% 4320)?

yes.

and so is also the case for Squid-2.4 if none of your defined
refresh_pattern matches the request, if you have any defined.

This change only makes a difference for ftp:// directory listings and
gopher:// requests, and only if you do not have a single refresh_pattern
defined in squid.conf.

With Squid-2.4 these was cached even if you did not have any
refresh_pattern settings in squid.conf at all but most often stopped to
be cached if your defined any custom patterns without having the
suggested defaults also defined in your squid.conf.

With squid-2.5 you need to have matching refresh patterns for these to
get cached, making the behavior consistent when adding/defining custom
refresh_pattern rules.

-- 
Henrik Nordstrom <hno@squid-cache.org>
MARA Systems AB, Sweden