Hi Felix, thanks for willing to debug the issue. Here's a primer:
https://www.isc.org/blogs/2023-BIND-memory-management-explained/ The basics are: 1. configure stats channel 2. look at the memory distribution (internal) to see where the memory goes 3. if there's a really runaway memory, we can use the jemalloc profiling to see exactly where the memory goes Ondrej -- Ondřej Surý (He/Him) [email protected] My working hours and your working hours may be different. Please do not feel obligated to reply outside your normal working hours. > On 15. 9. 2025, at 23:03, Felix J. Ogris <[email protected]> wrote: > > Hi, > > I have noticed that Bind 9.20.x on FreeBSD 14.2 and 14.3 consumes more and > more memory when being used as a resolver. > While top reports a SIZE of 4800 MB and RES of 4600 MB, the XML statistics > channel just reports 209053061 bytes for both malloced and in use. This > instance has been running for about 11 days. > Relevant named.conf snippets: > > zone-statistics no; > dnssec-validation no; > max-cache-size 1024M; > > memstatistics has not been set. > > There are 169 (3 automatic) zones configured statically to ground zone > "127.in-addr.arpa", zone "example.com", and such. No RPZs, no dynamic zone > updates. It runs as unprivileged user in a chroot on a VM with 2 CPU cores. > rndc flush did never release any memory. Instead, I sporadically observed > SIZE increasing as soon as rndc flush returned. > On the very same system, Bind 9.18.x levels off around 300-400 megs, even > when it had been running for several weeks. > Both 9.20.x and 9.18.x were compiled locally from the FreeBSD ports system > using just these four options: > > IDN (International Domain Names support) > TCP_FASTOPEN (RFC 7413 support) > STATS_XML (Enable XML statistics channel) > GSSAPI_NONE > > FreeBSD 14.3 provides clang version 19.1.7 as C compiler, and jemalloc > 5.2.1-0 as system memory allocator. Machine type is amd64. > As the memory usage of my resolver at home grows more slowly, I assume the > growth rate depends on the number of queries and/or answers. > When being used as an authorative server, Bind 9.20 uses very little memory > and does not increase, comparable to 9.18. > I am willed to debug this behaviour, but will need support to do so. Any > suggestions are welcome. > > -Felix > -- > Visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from > this list. -- Visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list.
