Clarify whether replicated streams are Full-Sync or not about nats.docs HOT 1 CLOSED

Stream replication in NATS implements the Raft protocol which provides quorum-based consistency of writes. This means that when a cluster receives a message to be stored in a stream, a majority of the replicas must successfully store the message before an ack is sent back to the client. For three replicas the majority would be two. For five replicas the majority would be three. The other replicas will still receive and/or sync the data, but only a quorum needs to store before an ack is returned to the client.

In the case of replica(s) being unavailable (server down, etc), the same rule applies. As long as there is a majority available, writes will still be accepted to the stream.

from nats.docs.