Support multiple cb-network controllers

[yunkon-kim]

It would support multiple cb-network controllers without a scheduler.

Each host (VM) records the dynamic changes of its local network. For example, VM1 can record its local network changes twice and VM2 can record its local network change once. In any order, the cb-network controller must distinguish those and only need to deal with one of them.

To distinguish each sporadic update in multiple data sets, I have developed a mechanism with the lease and compare-and-swap (CAS). The cb-network controllers try to lease a temporal key by CAS. (It's like acquiring a workload (i.e., handling of data update).).**

• A cb-network controller acquires the temporal key if the key doesn't exist.
• The other cb-network controllers will pass to acquire the key because the key was already generated by the others.

The temporal key will be removed after a certain period of time (i.e., TTL was assigned to the lease)

[Proposed method]

• Try to acquire a workload by Compare-And-Swap (CAS) and Lease
• Handle the workload by a cb-network controller, which acquires the workload

[yunkon-kim]

[A sketch for multiple cb-network controllers concept and missions]