Bind-9.6 and Heavy Cpu Load

Jeff Lightner jlightner at
Sun Sep 27 12:06:45 UTC 2009

If this was an existing installation and the CPU load suddenly increased
you might want to check where the queries are coming from.  Not so long
ago I found what appeared to be a brute force attack on DNS server by
sending the same queries over and over from the same range of IPs in
Romania.   Blacklisting that range resolved the issue.

-----Original Message-----
From: bind-users-bounces at
[mailto:bind-users-bounces at] On Behalf Of Fajar A. Nugraha
Sent: Saturday, September 26, 2009 2:47 PM
To: Bind
Cc: Bind Users List
Subject: Re: Bind-9.6 and Heavy Cpu Load

On Sun, Sep 27, 2009 at 1:28 AM, Bind <bind at> wrote:
> The number of requests is 2700 recieved pps and 2500 transmit pps.

> also i forced it to use both cpu`s,(in prstat -a command the STATE
> column,shows named uses cpu0 then after moment it changed to cpu2) but
> cpu load exists.

- the numbers you gave are queries per second
- your v880 has 1.5GHz Ultra sparc III CPU (or similar)

and considering:
- BIND's atomic locking performs better on some platform than others
(my experience was on x86 vs ppc)
- query per second numbers on

I'd say you're probably cpu bound and there's nothing much you can do
about it. You already disabled logging, right? This is just a rough
estimate though, YMMV. If you have a 2 or 4-way x86 server you can try
it and see if it performs better.

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