increasing memory usage (using rpz zones)

Hanspeter Kunz hkunz at
Wed Oct 14 21:29:10 UTC 2020

Hi all,

[replying to my own post]

Apparently it is normal that unbound uses *a lot of RAM* after the
initial load of the rpz zones (point 1 below).

The problem 2, however, is still unsolved. But I was able to track down
the memory leak (point 2 below) somewhat: it only occurs if unbound is
configured to listen on more than one IP address.

I filed a bug here:


On Tue, 2020-09-29 at 14:25 +0200, Hanspeter Kunz via Unbound-users
> Hi all,
> I recently upgraded to unbound 1-11.0 because I needed support for
> rpz
> zones. while the rpz zones work fine, I realized rather quickly, that
> the memory unbound uses is much higher than before and *increases*
> over
> time. when I use a rather large rpz zone it actually unbound's memory
> requirements increases rather dramatically. 
> These are my observations:
> ---
> 1. memory consumption at startup (as reported by pmap)
> a) starting unbound without any rpz zones: 248M
> b) starting unbound with all but the problematic rpz zone: 526M
> c) starting unbound including the problematic rpz zone: 10G (!)
> the total file size of my rpz zones ist 103M, the problematic rpz
> zone
> has a size of 95M. i.e. it is much larger than the other zones. it
> has
> ~1 million entries.
> are such increases in memory consumption to be expected? 
> restarting unbound for case c) also take a very long time (~20s),
> which, however, is reasonable.
> ---
> 2. increased memory consumption after rpz zone transfers/reloads
> as soon as an rpz zone is updated (and I assume unbound triggers a
> transfer and a reload of the zone), memory consumtion increases
> further, for example
> startup: 10G
> 1st reload of the problematic rpz zone: 19G (!!)
> when one if the smaller rpz zone is reloaded, memory consumption
> increases too, but only much slower.
> ---
> I am running debian stable (buster), unbound 1.11.0 (from debian
> backports).
> unbound is configured for 4 threads and I used the suggestions here
> I can send unbound.conf and rpz.conf if that helps, although
> essentially the same settings worked well for years (unbound 1.6.0-
> 3).
> Best,
> Hp
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