9.16.27 (Raspberry PI package) - memory usage

[vom513]

Hello,

I have an rPi here at home running as a second DNS server to my main (non-rPi) bind instance.  The pi unfortunately only has 1G ram.  I’ve set max-cache-size to 50% and verified it took effect:

root at ns2:~# grep size /var/log/daemon.log
May  1 12:38:23 ns2 named[6295]: /etc/bind/named.conf.options:42: 'max-cache-size 50%' - setting to 461MB (out of 922MB)

This guy only has maybe 10 zones (small internal dns, rdns, some rpz feed zones).  It also has the built-in/empty/rfc1918 zones.

After a day or so - I see that bind is using 800M+  It behaves like it’s using the default 90% max-cache-size setting.

I just saw another thread on the list related to memory issues, and I also did some of my own reading regarding internal memory allocation in 9.16 vs. 9.18.  I don’t pretend to fully understand the details there…  The one thing that caught my eye was that the memory allocation changes were backported to 9.16.25+.  I’m running "BIND 9.16.27-Raspbian (Extended Support Version) <id:96094c5>” - wouldn’t I have these backported changes ?

So my question is - if it’s not cache that’s eating memory - what else could it be ?  Is there something else that’s gradually eating memory that I’m not aware of ?

Is there anything I can do to further troubleshoot - or is the real solution to upgrade to 9.18+ and/or get a machine with more RAM ?

Thanks.