bind machine performance for around 500 domains

[David Nolan]

--On Tuesday, May 02, 2006 10:29:39 -0700 Gaud <gaud at gaudtechnologies.com> 
wrote:

>
> I expect that this server will have to handle 350,000 hit per day
>


Thats all?  Authoritative only, or recursive queries as well?

I've got a production authoritative dns server with 420 zones (forward & 
reverse), thats taken 275,000 requests in the last 2.5 hours.  This is a 
slave that does around 150K incremental transfers from the master per day. 
The servers is a P3 1.4Ghz processor, with 1G of RAM.  Linux 2.4.30, Bind 
9.3.1.  Bind is using 19M of RAM.  The average CPU load on the server is 
0.019, with a max in the last day of 0.25.

I've got a recursive server thats taken 475,000 requests in just under 3 
hours, same hardware & software, average CPU load of 0.18, max of 1.34. 
Bind is using 90M of RAM.

I can't recall ever having a performance problem with my authoritative 
servers.  The recursive servers used to occasionally have issues during an 
incoming spam wave, because they were getting bombarded with RBL queries by 
the mail servers.  We added one extra machine to our pool of servers to 
help with the load, but ultimately the solution was to add an additional IP 
to each of the DNS servers and configure the mail servers to send queries 
to those IPs.  Since Bind queues incoming request per-interface, the 
overload of queries from the mail servers no longer effected the ordinary 
user DNS requests.

-David Nolan
 Network Software Designer
 Computing Services
 Carnegie Mellon University