4.0 Overview

4.0.1 Node Lifecycle

Each node cycles through four states:

BOOT → REGISTER → SYNC → STEADY.

Nodes in STEADY phase participate in voting and replication; failed nodes trigger redistribution.

4.0.2 Self-Healing Algorithm

When a node drops below the quorum signal threshold, the mesh automatically triggers:

1. Delta replay from last SnapshotID
2. Counter parity recheck
3. Reallocation of cell authority

4.1 IBM Cloud Regions, Zones, and HA Topology (Live Behavior) : [U2]

Each region acts as an authority zone — nodes broadcast heartbeats through region-scoped multicast channels; failover crosses regions when TTLs expire.

[U2] : https://cloud.ibm.com/docs/vpc?topic=vpc-about-vpc

4.1.1 Heartbeat Stream

async fn heartbeat_loop(node_id: Uuid, tx: Sender<Heartbeat>) {
    loop {
        tx.send(Heartbeat::new(node_id)).await.ok();
        tokio::time::sleep(Duration::from_secs(2)).await;
    }
}

Each node publishes heartbeats tagged with region and zone metadata.