Re: [squid-users] round robin DNS and the occassional failing IP.

sön 2008-02-24 klockan 03:54 +1100 skrev Tim Connors:
> I am having trouble on two machines on two completely different networks,
> both using squid -- for months now, a reasonably portion of the time,
> squid fails to get through to google.com.au for the first minute. A
> tcpdump revealed that it was failing when trying to contact the same
> 72.14.203.104 host. After a minute, squid would try the next host in the
> cached DNS result. Since both machines have 4 addresses in their cached
> result of google.com.au, and both included 72.14.203.104, one in 4
> searches would take a minute to get a result.

And google set the TTL of their DNS response to only 5 minute so after 5
minutes Squid's memory of the bad IP is gone..

> In the event that a hostname resolves to n>1 IPs, and one or more of them
> m<=n-1 are timing out (or connection refused and certain other error
> conditions), I think squid should cache this result for a configurable
> time (of the order of days or until a restart, or until DNS has
> refreshed its list of IPs for that host), and then not try that IP
> again until it has exhausted its supply of IPs corresponding to this name.

It caches the bad status until the DNS entry expires or a user forces a
reload.

Regards
Henrik