Performance issues

[John Hascall]

Is this happening about every hour?
We've seen this when named decides it is cleaning time.
http://www.zytrax.com/books/dns/ch7/periodic.html#cleaning-interval

John


> Hi,
> 
> We are running bind 9.3.3 on 1 hidden master and 2 slaves with 2GB  
> Ram and "old" 2GHz Xeon. We have 150 queries/s average on each slave  
> with 300 queries/s in max peak. On these servers we have about 150  
> "lights" zones with Authority. We have done 2 views, one for our  
> client (about 20'000 in peak) which is open for recursives queries  
> and one for external which provide only the zones we have authority  
> on (no cache for it).
> For example of queries repartition, at 20h00 yesterday we have  
> about : 5 failures/s, 70 recursives/s, 40 nxdomain/s, 5 nxrrset/s and  
> 150 success/s...
> 
> We have some performance issue on the slaves. Sometimes the queries  
> on one of our authority zones (on one A record) can take some seconds  
> to be executed ! (in average it takes less than 8ms)... This  
> performance issues are not linked to load issues on server. We are  
> monitoring load (average load is 0,1 per minute), packets (average is  
> 150p/s), bandwith (average is 20kB/s), processus, ping time, ... The  
> bind performance issues can occure when we have only 150 queries/s  
> with a low load... we see nothing strange in the stats (like tcp or  
> udp explosions, or very high number of packets)...
> 
> Are these issues "normal"? We are thinking about a solution with 2  
> front servers providing only cache services (open to our clients  
> only, for recursives) and with 2 slaves and 1 master dedicated to the  
> authoritatives zones (nor recursive, hidden to our clients). Could  
> this be a real solution for better performances?
> 
> Regards
> 
> David
> 
> ##### some of our named.conf #####
> # blacklist contains only 1 IP
> # recursive is quite high... because
> # sometimes 1000 recursives is not enough
> ##############################
> options {
>          directory       "/etc/namedb";
>          pid-file        "/var/run/named/pid";
>          dump-file       "/var/dump/named_dump.db";
>          statistics-file "/var/stats/named.stats";
>          version         "None of your business";
>          // we accept transfers only to our slaves
>          allow-transfer {
>                  key dns3-dns2.; # Our slave
>                  key dns3-dns1.; # Our slave
>          };
>          recursive-clients 2500;
>          blackhole { blacklist; };
> };
> 
> view "internal-in" in {
>          match-clients { our_clients; };
>          recursion yes;
>          additional-from-auth yes;
>          additional-from-cache yes;
>          include "zones.conf";
> };
> 
> view "external-in" in {
>          match-clients { any; };
>          recursion no;
>          additional-from-auth no;
>          additional-from-cache no;
>          include "zones.conf";
> };
> 
>