You switched to the new one while the old one was down... that's not the same as switching between two live systems. Though, perhaps, in this particular case, the procedure might be.

Ah, I see. If we have to bring HN down for a few minutes, or (more likely) put it into readonly mode for a bit, we can do that–especially if it makes the process simpler and/or less risky.

Lol missed this comment while writing mine.

Not a problem in a thread about replicas and redundancy :)

So there's this great joke about cache coherency.

I'm sure you'll get it, eventually.

He can choose to do it the easy way and just take an outage to move it, or possibly go into read only mode while moving.

We tend to over engineer things as if it’s the end of the world to take a 10 minute outage… and end up causing longer ones because of the added complexity.