[Unbound-users] unbound performance tuning
beastie24 at gmail.com
Sun Oct 19 12:18:55 UTC 2008
I'm using unbound for a couple of months as a default recursor in one
middle level installation and I like it so far :)
Now I have a paln to replace BIND with unbound in one big ISP network
(average recursion load is 50K requests/sec).
I have a question about how to tune unbound to allow him handle that
volumes. That parameters should I adjust to get maximum performance?
We have two CPU socket quard core Xeon server with 12GB of RAM running
FreeBSD 7 STABLE. Unbound will be compilled without libevent and
without threading, and we will start 8 unbound processes (num-threads:
8) using 1024MB cache size for each.
I have a couple of ideas about that should be tuned, but I would like
to ask - am I right, or I'm missing somthing? This post is request for
AFAIK unbound handle incoming requests this way:
So, I should pay attention for that potential bottlenecks:
1) num-queries-per-thread: - "The number of queries that every thread
will service simultaneously". If one process will have more than this
nuber of simultaneousl requests then it will drop exceeded requests?
2) msg-cache-size: - After queue has arrived into unbound it will be
saved in msg-cache and will wait there until resolving process will be
free to handle it? If msg-cache has no free space then new arrived
queues will be dropped?
3) outgoing-range: - the nuber of random ports that resolving process
can simultaneously use for sending requests out of unbound. If this
nuber is low, then msg-cache will grow in size and that can produce
So, if that is right, I should set num-queries-per-thread: to 10240,
msg-cache-size: to 512MB and outgoing-range: to somthing close to 1024
(1024 - the limit of unbound's builtinmini-event event handler because
I don't use libevent). I will tune FreeBSD sysctl limits for this
(default FreeBSD 7 ulimit -n is 12328 and ulimit -d is 512M).
I assume this unbound.conf will be ok?
access-control: 0.0.0.0/0 allow
access-control: ::0/0 allow
Thanks in advance for any comment.
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