Bind9(9.3.2p1) "out of memory"

[Stefan Schmidt]

On Thu, Sep 21, 2006 at 02:16:32PM -0400, Adam Young wrote:
> Hey guys/girls,

Hi guy,

> I've limited my package of bind9 to 3GB of memory for cache using
> 'max-cache-size'.
> 
> However today, I attempted to make a change and reload the configuration and
> received the following:
> 
> $ sudo /usr/sbin/rndc reload
> rndc: 'reload' failed: out of memory
> 
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
> 24677 bind      25   0 3068m 2.9g 2336 S 99.9 73.6   1567:08 named
> 
> $ uname -a
> Linux ns1 2.6.17-i686 #1 SMP Mon Jul 31 14:27:54 EDT 2006 i686 GNU/Linux
> 
> Any idea why limiting cache size, should have any effect on the ability to
> reload your configuration?

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 [3]?
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.

[1] http://www.spack.org/wiki/LinuxRamLimits
[2] http://marc.theaimsgroup.com/?l=linux-kernel&m=115691246628117&w=4
[3] http://www.campin.net/DNS/graph.html

	Stefan