Malachi.Cluster.RingMachine (malachi v0.22.7)

A ra (Raft) state machine that replicates Malachi.Cluster.Ring, the cluster's durable routing topology.

apply/3 delegates to the pure, deterministic Ring.apply/2, so the ring becomes Raft-replicated with no logic in the machine itself, exactly the shape of Malachi.Cluster.MetadataMachine and Malachi.Cluster.LeaseMachine. Unlike the lease machine it needs no clock: the ring's guards are compare-and-set on version and fence, both carried in the command.

Versioned through Malachi.Cluster.MachineVersion, which also keeps an unknown command from raising here: Ring.apply/2 has no catch-all clause.