DNS Server Farm

[Scott Lambert]

On Tue, Aug 05, 2003 at 07:42:21AM +0200, Blaz Zupan wrote:
> > Seeing as a "real" load balancer, like a ServerIron XL, can be
> > found on Ebay for next to nothing these days, it's a very workable
> > solution.  We just built such a solution for a network with about
> > 550,000 users and it works just fine.  2 or 3 good boxes and a load
> > balancer will also be much cheaper than a box at each pop.
>
> But you still have a single point of failure. You have all your boxes
> located at a single location. If you have a power failure or other
> catastropic event at that location, your whole DNS setup fails, while
> the rest of the network works just fine, just without a working DNS
> server. Same thing if your load balancer fails.

What he said.  Even with my twenty thousand users, I put a DNS server   
at each of the regional hubs.  That way any of the regions could be     
down without affecting the other users.  It happenned more often than   
I liked despite us doing everything right.  Ok, almost everything.      
Ninety percent of our downtime was telco related.  It was a rural ISP   
spread out across most of one state dealing with 5 or 6 telcos.         

I really wanted a DNS / outbound SMTP server in each PoP but couldn't
cost justify it.

If you want a load balancer, and they are cheap, why not put one in each
regional hub and have several smaller clusters?

-- 
Scott Lambert                    KC5MLE                       Unix SysAdmin
lambert at lambertfam.org