ReplicaIsBehind returns whether the given peer replica is considered behind according to the raft log.

ReplicaMayNeedSnapshot determines whether the given peer replica may be in need of a raft snapshot.

LocalReplicaNotLeader means that the local replica is not the Raft leader, so it does not keep track of enough progress information about peers to determine whether they are in need of a Raft snapshot or not.

NoRaftStatusAvailable is only possible in tests.

NoSnapshotNeeded means that the local replica knows for sure that the peer replica does not need a Raft snapshot.

ReplicaMatchBelowLeadersFirstIndex means that the local Raft leader has determined that the peer replica's latest matching log index is below the leader's log's current first index.

ReplicaStateProbe means that the local Raft leader is still probing the peer replica to determine the index of matching tail of its log.

ReplicaStateSnapshot means that the local Raft leader has determined that the peer replica needs a Raft snapshot.

ReplicaUnknown means that the peer replica is not known by the Raft leader and is not part of the Raft group.

ReplicaNeedsSnapshotStatus enumerates the possible states that a peer replica may be in when the local replica makes a determination of whether the peer may be in need of a Raft snapshot.