In <20070707165226.GA22103@dementia.proulx.com>, Bob Proulx wrote:

> Tony Houghton wrote:
> > SA used to kill a different router I used to have, but I don't think
> > that's the problem here.

>
> I don't see how even a low end router would have a problem with the
> amount of data from DNS lookups that could be generated. It must have
> been something else.


I'm pretty sure it was that. I switch my PC off overnight and I noticed
the router would crash shortly after switching it back on and deduced it
was because of the large volume of mail being fetched in one go. It was
OK if I got my PC to use my ISP's DNS instead.

> > I temporarily pointed /etc/resolv.conf to my ISP's servers and
> > restarted spamd, which you'd expect to make at least some
> > difference, but it didn't really. Besides, I can still freely browse
> > the web etc while SA is stalled on these lookups.

>
> You might want to try out one of the RBL check tools.
>
> http://rblcheck.wiki.sourceforge.net/
>
> Basically 'rblcheck 208.77.188.166' and see how long that takes. It
> is very similar to what SA would be doing internally. If that is slow
> then you have a smaller problem to debug. If that is fast then SA's
> dsn lookup is probably not your problem and you can look at other
> things that might be running slowly.


That seems to take about 5 seconds when given a new address, under 1.5s
when repeating one. spamassassin always takes over 10 secs. The debug
output I posted seems to say it is DNS timeouts. There's a whole load of
activity to start with, then it prints several messages which look like
it's waiting for the DNS queries to complete, then a load of messages
saying "dns: timeout", usually after 11 seconds.

--
TH * http://www.realh.co.uk