[zellyn]

I can speak most directly to Go, where I've been working. You could potentially use one of the maps-to-DNS service discovery systems, although that's limited.

At Square, we created a custom balancer (https://godoc.org/google.golang.org/grpc#Balancer) which not only handles updates from the service discovery system in order to manage the pool of connections, but also handles which connection to use per-call (so we can do targeting of specific capabilities, datacenters, etc.)