Re: bind timeouts

On 17 May, Sven Willenberger wrote:
> On Mon, 2004-05-17 at 16:50 +1000, Dennis Kristensen wrote:
>> On Tue, 2004-05-11 at 19:36, Cyrille Lefevre wrote:
>> > On Mon, May 10, 2004 at 08:21:15PM -0700, David Wolfskill wrote:
>> > > >From: "Cyrille Lefevre" <clefevre-lists_at_9online.fr>
>> > 
>> > CC -current
>> > 
>> > > >for some times, I have some troubles to send e-mails, they
>> > > >are returned w/ a host unknown error message (the relay)...
>> > > >I spent a whole day to track down the problem w/o success.
>> > > >...
>> > > >however, it seems to be located around bind, but I don't know
>> > > >if it's the client side or the server side which is broken,
>> > > >maybe the TCP stack !
>> > > 
>> > > >I'm running -current last updated around 18 April 2004.
>> > > 
>> > > I have been tracking both -STABLE and -CURRENT daily for quite a while;
>> > > I don't recall seeing the symptoms you report.
>> > 
>> > someone (Dennis Kristensen) reports me to have similar problems but
>> > forget to CC -current :(
>> 
>> After observing this for some days now (with no progress towards a
>> solution), i think this might be a problem with the kernel rather than
>> BIND. I have a 5.2.1-p5 system that shows the same symptons. It is
>> lightly loaded and the above mentioned symptons start appearing after
>> 1-3 days of uptime. A restart of BIND does not change anything, but af
>> reboot of the system gives me another few days of correct operation.
>> 
>> I hope the above can give someone more hints to what might be going on.
>> I also hope to get some pointers to resource counters i can check to try
>> an identify if something is leaking.
>> 
>> The mail system is standard qmail, qmail-scanner with clamav and
>> spamassassin and vpopmail - all from ports.
>> 
>> Thanks for any hints or information in advance,
>> Dennis Kristensen
> 
> We had issues with qmail and bind playing nice together, with frequent
> "CNAME_lookup_failed_temporarily" entries in the logfiles. Having the
> mailserver use a nameserver that is running tinydns/dnscache solved the
> problem (not really a big surprise knowing djb's disdain for the isc
> product). Why you would start having this issue I don't know, but you
> may want to try the tinydns/dnscache alternative.

<http://www.google.com/search?hl=en&lr=&ie=UTF-8&q=qmail+CNAME&btnG=Search>

This appears to be a fairly common problem and can have a number of
different causes.  The above web search turns up a bunch of info on how
to debug and fix the problem.