[Pacemaker] designing a load balancer - request for comments

[Klaus Darilion]

Hi!

I wonder if someone gives me some ideas how to achieve automatic
failover between my redundant load balancers. The setup I want to
implement is:


            server1                   server2
             ip1                        ip2
                <-----virtual-IP------->

The load-balancer is a SIP proxy (Kamailio) which acts as registrar and
load balancer for several Asterisk servers.

Kamailio should always be running on both servers. Replication of
Registrations is done on SIP level between the to servers (using the
'real' IP). The Registrar/LoadBalancer service itself is provided on the
virtual-IP, thus the SIP traffic is handled either on server1 or server2.

If the Kamailio process dies, it should be restarted. If it fails to
start or fails to often (flapping) the virtual-IP should be migrated to
the other node. Of course failover should also happen if one server dies
completely.

I wonder how I should implement this. Of course the virtual-IP sould onl
be active on a host where Kamailio is active too.

How do I make Kamailio active on both nodes? Just a "clone" as with the
"ping resource"?

How do I try to recover a Kamailio problem (restart) a few times before
migrating the virtual-IP to the other node?

I do not expect a complete configuration, but would appreciate if
someone can suggest a "big picture", e.g. cloning, groups, dependencies ...

Thanks
Klaus