Maintained by: NLnet Labs

[Unbound-users] Performance tuning tips?

Sven Ulland
Thu Feb 7 14:09:15 CET 2013


On 02/07/2013 01:45 PM, Jaco Lesch wrote:
> num-threads: 64

This is likely to work against your goal, as thread management / query
distribution will start using more cpu than necessary. I'd rather tune
it down to a reasonable number that can still comfortably serve all
requests.

I did the same sort of optimization as you, and set threads to 16.
While it worked fine, I later switched to 4 threads after figuring out
a bit more about threads and how things work in the OS:

http://www.unbound.net/pipermail/unbound-users/2012-July/002452.html
https://unbound.net/pipermail/unbound-users/2012-February/002240.html
http://serverfault.com/questions/411868/multithreading-with-multi-queue-nic-on-smp-system

It may not apply directly to your Solaris setup, but it's worth
investigating.

My resolvers consistently serve 30k-40k+ reqs/sec (some threads are up
to around 12k reqs/sec each, due to uneven balance), with load around
0.6 and CPU use around 2.0--10.0% sys and ~2.0% user, depending on the
hardware it runs on (Intel Xeon L5520 or L5640, 2x socket, quad/hex
cores with hyperthreading). I run them on Linux 3.2.

sven