DDNS, Notify and IXFR

[Jerry Scharf]

Kevin,

I have the same take that Brad has that there isn't a loop here, since
it's the updates that cause the notify not the IXFRs.

I think adding a config option that sets a collection time for aggregating
notifies would be nice, but that is based on being ignorant of the code
complexity of doing such. I think it would be better to have it operate as
a damping timer after a notify is sent out rather than a delay on sending
a notify. I would expect this to be a per zone option.

This has been looming for a while now. It's hard for me to really come up
with a strong case for DNS at slave update rates < 5-10s, but it's easy to
get in the burst situation even if it's not steady state like Kevin
described.

jerry