[unbound] memory usage

[Olivier Benghozi]

Hi,
We had some memory issues here with unbound after a Debian update with a
new kernel.
It was a (well known) transparent_hugepage issue. Changed it from enabled
to madvise, problem fixed.

You might maybe (or maybe not) hit the same issue?
Check https://access.redhat.com/solutions/46111

And maybe just check for yourself right now on runtime:
echo madvise > /sys/kernel/mm/transparent_hugepage/enabled
echo madvise > /sys/kernel/mm/transparent_hugepage/defrag

then restart unbound...


Le sam. 16 mars 2024 à 04:02, Nicolas Baumgarten via Unbound-users <
unbound-users at lists.nlnetlabs.nl> a écrit :

>
> Hi,
> we have been using unbound for a long time, and we are very happy with it.
>
> But I would like to know a little about memory usage.
> LAtely we are seeing that unbound process grows using all memory and start
> swapping causing a big loss of performance (latency, dropped packets, etc)
>
> The question is that stats metrics (mem*) are stable . They rapidly grow
> after startup and stay at a logical
> maximum and don't keep growing.
>
> But the process size does.
>
> For example, two servers, same config, same hardware:
> version 1.9.1, on redhat 8.7
>
> *Server A uptime 2 hours:*
> unbound-control  stats_noreset | grep mem
> mem.cache.rrset=285212642
> mem.cache.message=142606338
> mem.mod.iterator=16748
> mem.mod.validator=25689380
> mem.mod.respip=0
> mem.mod.subnet=61555940
> mem.streamwait=0
> mem.http.query_buffer=0
> mem.http.response_buffer=0
>
> Unbound proc *RES size 1.6GB, VIRT 1,8 GB*
>
> *Server B uptime 6 days. *
> mem.cache.rrset=285212302
> mem.cache.message=142606461
> mem.mod.iterator=16748
> mem.mod.validator=25689867
> mem.mod.respip=0
> mem.mod.subnet=142614402
> mem.streamwait=0
> mem.http.query_buffer=0
> mem.http.response_buffer=0
>
> Unbound proc *RES size 5.5GB, VIRT 6.2 GB*
>
> As you can see the only difference in memory is the mod.subnet which is
> 60Mb vs 140Mb, but this limit is reached at 4  or 5 hours of
> running and stays there.
>
> Why  is it using almost 4 GB more after a couple of days while caches are
> stable??
> There is some way to control this?
>
> Whe are restarting unbound every two days now (while waiting for a little
> bit more of ram)
>
> Thanks!!
>
>

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