Bind9(9.3.2p1) "out of memory"
Mark_Andrews at isc.org
Thu Sep 28 13:38:44 UTC 2006
> In article <efg26t$15un$1 at sf1.isc.org>,
> "Adam Young" <adamy at mountaincable.on.ca> wrote:
> > Hi Stefan,
> > > No idea what BIND does there but i remember there is (was?) a hard limit
> > > of 3GB RAM
> > > per user process [1|2] in default x86-32 kernels.
> > > But as you mentioned you limited max-cache-size to 3GB the question that
> > > springs to my mind is: Do you really need such a huge working set for
> > > your cache? (Assuming its a caching-only server.)
> > > I have been quite lucky with just 380MB on several machines after i used
> > > two split processes per machine and disabled threading with bind9.
> > > Do you already monitor your servers query-load ?
> > > I'd say try limiting the max-cache-size to 2 or even 1GB and then look
> > > at your graphs and see if it has any bad impact on your users.
> > I think I may have found a reason why there are so many queries and why the
> > cache is growing so large.
> > It looks like it is trying to tag on the domains I've listed in
> > /etc/resolv.conf with "search" to either all of the queries, or ones that
> > are failing.
> That's what the "search" option is for! Whenever a lookup fails, the
> resolver tries again with these domains appended.
> > Do you know how to stop this? I tried removing them and restarting bind, bu
> > it still shows the following being queried (ie.):
> > Isc.org
> > Isc.org.localnet.
> > Isc.org.mountaincable.net.
> It shouldn't continue searching after a successful lookup. You need to
> investigate the client, this isn't a problem with the server.
The client is most probably AAAA queries in series rather than
in parallel with A queries. The resolver doesn't stop searching
on NODATA responses.
look for Isc.org, Isc.org.localnet and
Isc.org.mountaincable.net A records stopping on first
match then look for Isc.org, Isc.org.localnet and
Isc.org.mountaincable.net AAAA records stopping on first
looking for Isc.org A and AAAA records and stopping
on either matching then if no match Isc.org.localnet
A and AAAA records and stopping on either matching
then if no match Isc.org.mountaincable.net A and
AAAA records and stopping on either matching.
I can only presume not stopping on NODATA was to handle
looking for A records in the presence of wildcard MX records
in pre RFC 1535 aware resolvers which walked the search
list before multi-label names were tried as is. Most of
the early use of wildcards was to handle email.
> Barry Margolin, barmar at alum.mit.edu
> Arlington, MA
> *** PLEASE post questions in newsgroups, not directly to me ***
> *** PLEASE don't copy me on replies, I'll read them in the group ***
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