Re: [squid-users] Squid Proxy not caching DNS

On Tuesday 08 July 2003 09.25, chisholm 27 wrote:
> Hi Henrik,
>
> Thanks. But shouldn't it be not the DNS round robin problem as it's
> the nature of it ? Traversing to next page happens within seconds
> once connection & authentication completed, but the Squid proxy
> queried DNS again thus invoking round robin resolution.

The cause is the broken web server.

The DNS round robin is just was triggers the error in this broken
server.

The server plainly is not designed for a load balanced setup, or they
have selected a load balancing method which is not suitable for their
server. Pick one.

> Shouldn't it be the Squid proxy not caching name long enough (not
> at all here) after initial session established? There's a
> restriction where I am not allowed to add host file here. Can
> something be done on Squid caching ?

You do not need to add it to the systems hosts file, just the hosts
file user by Squid. See the host_file directive in squid.conf.

The side owner can retune their DNS to work better with proxies by
taking the following measures:

1. Make sure their DNS server only returns one IP address per DNS
query

2. Set the TTL of this DNS reply very high, making it very unlikely
the DNS data expires while a user actively browses the site.

However, this will seriously limit the benefits of their selected load
balancing method at the same time.

What should be done is that the site owner either fixes their web
server to share the session information between all servers in their
load balanced setup, or selects another method of load balancing
which keeps users on their assigned server. DNS is NOT such a
method.

Regards
Henrik
Received on Tue Jul 08 2003 - 01:40:22 MDT