Subject: Load (re)balancing for renewals.

From: Steve Gonczi <[email-masked]>
Date: Fri, 11 Feb 2000 14:01:35 -0500

Hello,

I have been thinking about how renewals happen when the DHC Failover
protocol is running.

If the primary server goes down several times, potentially all clients will
migrate over and start renewing from the backup.  
Even after normal operations are restored, the clients will keep renewing
from the backup. 

Currently there is no mechanism to migrate some of these renewing clients
back to the primary. (apart from shutting down the backup).
I posit that ideally, 50% of the clients renewals would be handled by each
server during normal operation.

What do you all think about using the load balancing protocol to accomplish
this?
During normal ops, the load balancing hash could be used to selectively
ignore renewal attempts. This would cause the ignored clients
to broadcast @t2, and as a result, switch over to the other server.

sG

---

From: Ted Lemon <[email-masked]>
Date: Fri, 11 Feb 2000 11:19:01 -0800

Hm.  What about sending the other server's IP address back in the
server identifier option once it comes back up, if you receive a
request for an address for which you're not the primary?  We could
then use your strategy to account for clients that don't notice the
switch.  We could also strategically send a short T2 (t1 == t2, for
example) to clients to which we are responding because the server that
is primary for them is down.

			       _MelloN_