bind-9.10.0-P2 memory leak?

Thomas Schulz schulz at
Mon Oct 13 18:31:37 UTC 2014

>> ...
>>> Heh thanks, yeah...initially I was erring on the side of caution and using
>>> 9.9.x because it's served us well (~20k recursive clients without any
>>> significant problems).  Meanwhile we've been keeping a close eye on
>>> community comments, and to be honest opinions wax and wane.  Just as I
>>> think it's stabilized, someone else complains.  I suppose sticking to
>>> 9.9.x a bit longer is wise.
>>> That said, based on the 9.10.1 fixes, we will run it through our own perf
>>> tests for comparison.  Upgrades are automated and easy, but I'd obviously
>>> like to go live with the latest version unless there is a strong technical
>>> reason otherwise.
>> FYI, 9.9 is the current Extended Support Version (ESV).  If you're
>> looking for a version of BIND with a long period of maintenance, there
>> will be ongoing 9.9.x, 9.9.x+1 etc. releases and interim patches if needed.
> I mentioned this earlier, but I have been seeing the very large increases
> in process size with Bind 9.9.5-P1 and 9.9.6b1. I have just installed
> 9.10.1rc2 on one of our secondary name servers. In time I will be able
> to see if 9.10.1rc2 shows a bigger increase in process size than 9.9.5-P1
> did. I have restarted 9.9.6b1 with max-cache-size 30M on our primary
> server. Both experiments will take some time before I can tell what
> is happening.

For those seeing this problem on bind 9.10.1, did you upgrade from 9.9.6
or from an earlier version of bind 9.9.*? As mentioned above, I am seeing
this problem on 9.9.6. I do not find bind 9.10.1 growing any faster than
9.9.6 does.

I restarted bind 9.9.6 with a max-cache-size of 30M. We have 3 views.
The inital process size was 36 MB. The process grew to 184 MB. It grew
to 596 MB without the max-cache-size being set and was still growing
when I restarted it.  BUT when I now do an rndc dumpdb -cache, the
named_dump.db file contains only the line

; Dump complete

and nothing else.

So, if you put any limit on the cache size, you will end up with an empty
cache. I do believe that there is a bug that needs to be fixed.

Tom Schulz
Applied Dynamics Intl.
schulz at

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