[Pdns-users] PDNS 3.3 flood

[Dmitry Rybin]

Hello!
There is a problem with work pdns 3.3 in nx-domain flood (15kqps)-
very slow answers or no answers.

Backend answers very fast (unbound) and not affected by this type of flood.
pdns-server                        3.3.1
linux debian 7.1

How can i fix it?

allow-axfr-ips=127.0.0.1
allow-recursion=XXXXXX, ::1, ::/0, ::1/128,
config-dir=/etc/powerdns
daemon=yes
disable-axfr=no
distributor-threads=1
guardian=yes
launch=bind
bind-config=/etc/powerdns/namedb/named.conf
bind-check-interval=300
local-address=127.0.0.1, XXXXXX
local-ipv6=::1
local-port=53
log-dns-details=yes
log-failed-updates=no
logging-facility=2
loglevel=4
module-dir=/usr/lib/powerdns
queue-limit=1500
receiver-threads=4
setgid=pdns
setuid=pdns
slave=yes
socket-dir=/var/run
webserver=yes
webserver-address=XXXXXXXXXX
webserver-password=XXXXXX
webserver-port=8081
version-string=4.9.8
do-ipv6-additional-processing=yes