Re: Does squid re-resolve hostnames named in squid.conf?

Bob Franklin writes:

>Hi,
>
>The UK Joint Academic Network (JANET) provides a National Cache which
>individual institutions are supposed to use as their upstream parents.
>To allow them (the National Cache managers) to move institutions around
>between different parent caches in their cache farm, they set up aliases
>for each site to use: 'rdg0.sites.wwwcache.ja.net' is one of ours.
>
>What I'd like to know is, if they change this alias to point at another
>machine, will Squid notice and switch over? Or, does it only resolve the
>hostnames -> IP addresses on startup and we'd need to HUP Squid
>occasionally to have it re-resolve these names?

Squid refreshes its neighbor IP addresses about every hour.

But it also uses the IP cache.

So if your IP cache has high TTLs, or if you use the _dns_ttl_
hack and the DNS entry has a high TTL, it will take longer than
one hour to switch over.

The BIND patches to get real TTLs into Squid can be found at
http://squid.nlanr.net/Squid/FAQ/FAQ-2.html#ss2.9

Duane W.
Received on Wed Sep 16 1998 - 16:21:37 MDT