BIND response time is relatively high

[alaa m zidan]

 hi ,
I noticed that at peak hours, BIND response time is relatively high for some servers.non-cached query takes over 700msI set some kernel parameters to tune the network and sockets for redhat 6 and set some global options to tune the BIND by modifying the cache settings, but neither I get the cache I set the limit to filed up, nor I get better performance.
some settings are as below,
kernel sysctl:============net.ipv4.ip_local_port_range = 1024 65535
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.core.rmem_max = 33554432
net.core.wmem_max = 33554432net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_max_orphans = 400000net.core.somaxconn = 4096net.ipv4.tcp_rmem = 4096 87380 33554432
net.ipv4.tcp_wmem = 4096 65536 33554432

bind named.conf global options:=========================        cleaning-interval 1440;
        max-cache-ttl 2419200;
        max-ncache-ttl 86400;
        max-cache-size 5120m;
server specs:===========memory is 8GB
memory usage is not exceeding 20% or 1.7GB while the cache is limited to 5GB as shown in the settings above, i wouldn't be more happier if i could have seen memory utilization spikes to the sky.
could you please suggest !!!


thanks



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/bind-users/attachments/20150126/1a69c9bc/attachment.html>