It's not meant to be a perfect analogy. The replication analogy is mostly talking about the tradeoff between performance and cost. So it's less about "replicating" the ip addresses (which is not happening). On that front, maybe distribution would be a better term. Instead of storing a single piece of data on a single host (unicast), they are distributing it to a set of hosts.
Overall, it seems like they are treating ip addresses as data essentially, which becomes most obvious when they talk about soft-unicast.
Anyway, I just found it interesting to look at this through this lens.
"Overall, it seems like they are treating ip addresses as data essentially"
Spot on!
In past:
* /24 per datacenter (BGP), /32 per server (local network) (all 64K ports)
New:
* /24 per continent (group of colos), /32 per colo, port-slice per server
This is totally hierarchical. All we did is build a tech to change the "assignment granularity". Now with this tech we can do... anything we want. We're not tied to BGP, or IP's belonging to servers, or adjacent IP's needing to be nearby.
The cost is the memory cost of global topology. We don't want a global shared-state NAT (each 2 or 4-tuple being replicated globally on all servers). We don't want zero-state (a machine knowing nothing about routing, just BGP does the job). We want to select a reasonable mix. Right now it's /32 per datacenter.... but we can change it if we want and be more, or less specific than that.
Overall, it seems like they are treating ip addresses as data essentially, which becomes most obvious when they talk about soft-unicast.
Anyway, I just found it interesting to look at this through this lens.