Thanks Seth. I'll make the adjustments and monitor performance.
On Wed, Nov 26, 2025 at 12:37 PM Seth Van Buren < [email protected]> wrote: > I think you missed the point. See: > https://nlnetlabs.nl/documentation/unbound/howto-optimise/ > > Set > *-slabs > to a power of 2 close to the > num-threads > value. Do this for > msg-cache-slabs > , > rrset-cache-slabs > , > infra-cache-slabs > and > key-cache-slabs > . This reduces lock contention. > > I service several hundred thousands of simultaneous clients with 10,000s > queries per second on only 12 threads. Cache response time is less than > 1ms, average response time is < 10ms. My hosts (I have 3 of them) have 16 > threads/cores each, I leave 4 threads to do some server busy work like > stats and logs collection. More threads doesn’t always mean better > performance and in your case since your slab count is low you’re going to > have a lot of lock contention. > > Cheers > > > *From: *sir izake <[email protected]> > *Date: *Wednesday, 26 November 2025 at 7:35 pm > *To: *Seth Van Buren <[email protected]> > *Cc: *[email protected] <[email protected]> > *Subject: *Re: How to measure cache hit resolution time in unbound 1.24.1 > > Hi Seth > > The server is dedicated for this purpose hence the high number of threads > > below configs are in place: > > num-queries-per-thread: 4096 > msg-cache-size: 10G > rrset-cache-size: 20G > key-cache-size: 1G > > Thank you > > On Wed, Nov 26, 2025 at 3:34 AM Seth Van Buren < > [email protected]> wrote: > > Your thread should be equal to or lower than the number of slabs. > > The thread count seems extremely high, you should not need so many. You > should set num-queries-per-thread. Try 16384 > > Can you also paste your memory settings and Cache settings? > > > *From: *sir izake <[email protected]> > *Date: *Tuesday, 25 November 2025 at 8:08 pm > *To: *Seth Van Buren <[email protected]> > *Cc: *[email protected] <[email protected]> > *Subject: *Re: How to measure cache hit resolution time in unbound 1.24.1 > > Hi Seth > > num-threads: 64 > msg-cache-slabs: 32 > rrset-cache-slabs: 32 > infra-cache-slabs: 32 > key-cache-slabs: 32 > ratelimit-slabs: 32 > ip-ratelimit-slabs: 32 > > The physical server is a dell 640 with specs below > > hw.ncpu: 104 > hw.model: Intel(R) Xeon(R) Gold 6230R CPU @ 2.10GHz > > Thank you > Isaac > > > On Tue, Nov 25, 2025 at 5:13 AM Seth Van Buren < > [email protected]> wrote: > > Home many cores/slabs are you using? > > *From: *Unbound-users <[email protected]> on > behalf of sir izake via Unbound-users <[email protected]> > *Date: *Tuesday, 25 November 2025 at 2:51 pm > *To: *[email protected] <[email protected]> > *Subject: *How to measure cache hit resolution time in unbound 1.24.1 > > Hi > > I have installed unbound 1.24.1 on FreeBSD 14.3 OS. My cache hit rate is > 76% with over 20% coming through recursive replies. > > The median time for recursive replies is 440ms while the avg is 520ms. > > This setup has been running for over 72hrs. I expect stats to improve but > that is not happening. > > Just wanted to find out if there is a way to measure the cache hit > resolution time in a dashboard? > > Can I do anything to improve cache hit ratio? > > Can I also improve the recursive reply time? > > I am using unbound_exporter to monitor stats in grafana > > My configs have been adjusted as follows: > rrset-cache-size: 20G > msg-cache-size: 10G > cache-min-ttl: 1800 > > I am using the root hint files directly on the server for recursive lookup > and not forwarding to any public resolver > > Thank you > > Regards, > Isaac > > >
