Minimize impact of NXDOMAIN requests

[Mark Andrews]

> Hi,
> 
> someone refer me to this list on discussing BIND
> specific questions.
> 
> In fact, we are using BIND9.2.5, BIND9.3.1 as cache
> server, which provide public service. I noticed that
> the NXDOMAIN keep increasing. The amount of NXDOMAIN
> forms a large part of cache server load. Is there any
> method to minimize impact of such requests on BIND?
> 
> Joe
> 
> 
> ********************
> I run "rndc stats" continuously( interval is less than
> 2 seconds), it's shown:
> 
> ====================
> success 17950622
> referral 225680
> nxrrset 1691861
> nxdomain 11203490
> recursion 3648017
> failure 1363923
> ...
> --- Statistics Dump --- (1116319437)
> +++ Statistics Dump +++ (1116322885)
> success 18889882
> referral 229772
> nxrrset 1809835
> nxdomain 11474755
> recursion 3825876
> failure 1415044
> ....
> --- Statistics Dump --- (1116322885)
> +++ Statistics Dump +++ (1116322886)
> success 18890342
> referral 229772
> nxrrset 1809868
> nxdomain 11474873
> recursion 3825976
> failure 1415052
> ....
> --- Statistics Dump --- (1116322886)
>  
> *********************

	What's the problem.  78 nxdomain/sec is not a lot. 

	If you really want to go futher you need to look at the
	queries themselves and look for patterns in them.

	Mark
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org