Heartbeating is only used for failure detection. Because raft is a consensus mechanism, failure detection is allowed to return false positives. In practice fals

Heartbeating is only used for failure detection. Because raft is a consensus mechanism, failure detection is allowed to return false positives. In practice false positives cause a blip in throughout as a new leader gets elected, but since they are rare it isn't a big problem. Because of the weak guarantees needed by the failure detector, you can use efficient mechanisms like gossip to reduce the bandwidth required. You pay some detection latency for that in return. It sounds like cockroachdb doesn't do that right now, but they could. It isn't some fundamental problem with consensus systems (it is a completely separate problem).