dealing with many domains/zones

[Barry Margolin]

In article <csavpf$21vg$1 at sf1.isc.org>,
 Robert Montgomery <mogtnomr at yahoo.com> wrote:

> If I have a large number of domains (500K+), is it
> faster to just rsync the zone & conf files (creating
> multiple masters) instead of using slaves & zone
> transfers?

How often do the zones change?  If they're fairly static, then there's 
not much point in optimizing this.  The overhead of checking for serial 
number changes in DNS is pretty light.

> I just need to do anything I can to minimize downtime
> during reloads and synching of slaves (or multiple
> masters).

If you use zone transfers, there's no downtime at all.  The server just 
reloads zones as it transfers them, with virtually no noticeable 
downtime while it's doing it.

If you use rsync, you'll have to reload the nameserver, which will 
require it to scan the directory for all the modified files.  If many of 
them have changed, and the zone files are large, there could be a 
noticeable hiccup.

However, one way in which the rsync may be better is if you need many 
zones to update at once.  With zone transfers, it may take quite some 
time for thousands of zones to transfer; each will be reloaded as they 
do, so they'll be out of sync while others are still waiting to 
transfer.  With rsync, you can do all the file transfers first, and then 
tell named to reload them all.

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