BIND 9.3.2 on FreeBSD 6.1 out of control

[Mark Andrews]

> Seems to me like this shouldn't take all that long though, should it?
> What's happening with me is that when it hits the max_cache_size, it
> consumes the CPU indefinitely. The only way to get it to settle down
> is to kill the process and restart it.
> 
> Out of curiosity, do most people set max_cache_size? If not, how is
> BIND not indefinitely growing? If they do, how big is it usually set?
> I'm getting the impression that most people are not experiencing the
> same problems as me, but I have no idea what I could be doing wrong
> because I'm not sure how everyone else has configured their servers.
> My configuration file hasn't changed too much since upgrading from
> BIND 8.
> 
> Patrick

	Every record has a TTL.  Records are removed once that time
	has expired either as a side effect of the lookup or in the
	regular cleaning sweep.  This is no different to BIND 8.

	You could be seeing this which is fixed in BIND 9.4.0rc1.

2116.   [bug]           'rndc reload' could cause the cache to continually
                        be cleaned. [RT #16401]

	If 'rndc reload/reconfig' (not rndc reload zone) was run
	while named was cleaning due to memory constaints it could
	run continually.

	If you are not running 'rndc reload' it should stop.
	
	Mark
 
> On 1/7/07, Mark Andrews <Mark_Andrews at isc.org> wrote:
> >
> > > So is no one else experiencing this sudden surge in CPU usage when
> > > BIND 9 hits its max cache size?
> >
> >         When the cache hits it's max size it trigger's a cleaning
> >         pass which randomly removes 25% of the RRset's in the cache
> >         as well as cleaning those that have expired.  That will
> >         take some cpu usage.
> >
> >         At some point it would be nice to make the overmemory removal
> >         be LRU based rather than random.
> >
> >         Mark
> >
> > > On 1/3/07, patrick <gibblertron at gmail.com> wrote:
> > > > But when it reaches that limit, is there any reason why the named
> > > > process starts eating up all CPU time? The memory size, I can handle
> > > > (and control) -- it's the unexplained CPU usage that concerns me.
> > > >
> > > > This server is a master for 143 domains, and will likely take on many
> > > > more. Is there a way I can see what's in the cache? I'd just like to
> > > > get an idea of how much memory each record takes up so I can do some
> > > > math for future planning on resource requirements.
> > > >
> > > > Patrick
> > --
> > Mark Andrews, ISC
> > 1 Seymour St., Dundas Valley, NSW 2117, Australia
> > PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org
> >
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org