Hi to all,
We upgraded our Caching-Publishing DNS servers from bind-9.2 to
bind-9.4.2-P2 at our 4 IBM x346 2 Core CPU 2.80GHz RHEL4-U3 x86_64 and
16GB Mem. But we had experienced problems w/ it with too many open files
problem. We resolved it by increasing the FD_SETSIZE at
/usr/include/bits/typesizes.h and defining the
STD_CDEFINES="-DISC_SOCKET_FDSETSIZE=4096" during compilation. Here's our
configure options:

--build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu
--target=x86_64-redhat-linux-gnu \
--with-libtool --enable-threads --enable-ipv6 --with-pic --with-openssl=yes
--enable-largefile \

Using iptraf, we're having total rates of around 20Mbps of traffic per
server. named.stats.txt showed that failure is very high and recursions
compare w/ success. CPU utilization averages at 40-60 per server and memory
rise to 20 to 50 % Utilization. We've seen many SERVFAIL from our tcpdumps
going to legitimate domains and about 3-5 times dig to a domain before the
queries became sucessful.

Is this CPU and Memory issue and do we need to upgrade our Boxes or its
bind(named) limitation?

We would like to seek your support and recommendation for our setup.