You not necessarily need to roll out a discovery service. You can put services behind a DNS, load balancer... and load balancers can be smart enough to mark a n

You not necessarily need to roll out a discovery service. You can put services behind a DNS, load balancer... and load balancers can be smart enough to mark a node as down. Now if you need more granularity than that, there's for instance Zookeeper ephemeral nodes, that get deleted when the client stops emitting heartbeats.