Experiment stateless loadbalancing using DTLS connection ID

[sbernard31]

The idea is to use DTLS connection ID to be able to load-balance traffic.

This idea is more detailed here.

[boaks]

I currently update my experimental Californium build-in cid load-balancer support.

Future Improvements

One technique, to eliminate the 20% penalty of forwarding and backwarding the messages, is to not backward them, just send them direct to the load-balancer. Normal load-balancer will drop such messages, but if a load-balancer use that message to update the destination entry, that results in close to NO penalty. The benefit of that is, that the load-balancer doesn't need to know about the cid-details, just that backwards traffic is used to "reverse update the address".

Maybe as idea for next year:

Adapt the rule

• if yes and packet comes from "not associated" real server, we drop the packet

to

• if yes and packet comes from "not associated" real server, update the association and we modify source address (source NAT) replacing real server address by the virtual server ip address.

optionally.