Logging question.

[MexiAce]

I am running a couple of DNS servers (Bind 8).  We use Keynote for web
perfomance statistics to our site.  I am seeing a number of DNS lookup
errors in the report.  What kind of logging can I enable that will tell me
if the DNS servers are being over-utilized and can't handle the load, or if
there is another reason that we are seeing the DNS lookup errors.  I am
assuming at this point that the number of DNS lookup errors are very small
compared to the successful lookups because of the amount of web traffic to
our site.

Thanks.