ns1 & ns2 load balancing

[Barry Margolin]

In article <dak36n$2q3e$1 at sf1.isc.org>,
 Brad Knowles <brad at stop.mail-abuse.org> wrote:

> 	The algorithm used inside of BIND is that it keeps track of 
> response time from all nameservers that are advertised as being 
> authoritative for a given zone, and every time a query request comes 
> in for a given zone, it will usually ask the nameserver that it 
> thinks is fastest.  The algorithm is designed so that it will age the 
> data it has over time, and will periodically ask the other 
> nameservers, to refresh the response time information it has about 
> them.

Also, if the response times of multiple servers are close, it treats 
them as equal.  It will either cycle through them or choose them 
randomly, I'm not sure, but either way should produce reasonable load 
balancing.

The important thing to remember is that no one outside the server 
administrator can tell the difference between master and slave servers.  
All they see is a list of NS records, with no priority specified 
(contrast this with MX records, that have an explicit preference field).  
So there's no reason for them to prefer the master over the slaves, and 
they're just as likely to query one or the other.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***