I have multiple caches which are co-located to each other and performing some low latency business logic through data affinity and backing maps between them.
Now I need to replicate "one" of those caches to another site (active-passive topology).
my understanding is that for the federation, I have to put the cache on a federated-scheme, and for co-location I need to keep it on distributed-scheme / cache service with relevant key association defined.
How do I combine the two?
Federated caching extends distributed caching. As such, the configuration between the two is very similar.
You could try changing your distributed-schemes to replicated-schemes for the caches you wish to be federated. For any caches that would use the scheme that you don't want federated, you can add <federated>false</federated> the appropriate <cache-mapping>.