How to know if all DNS have switched to the floating IP upgrade?
Added a floating IP to the server A, everything working and looking good.
Next step would be changing our DNS record to point to the floating IP instead of pointing to the droplet IP.
We expected the networking charts of the droplet to let us discern traffic from both IP's, but all we get is an aggregate traffic (I think/hope!).
How could we discern when it is "safe" to assume that every DNS in the world have replicated and all traffic is flowing through the floating IP, so we can float it to the new (upsized and updated) replicated server B?