Phase 4: Twin Event Journal

[nilsonfh]

Phase 4: Twin Event Journal

Milestone 3 — Ditto-Style Twin Layer. Roadmap phase 4 of 6.

Goal

Cada cambio de twin/atributo/relación emite un evento durable; el WS deja de depender de broadcasts in-process para multi-réplica.

Requirement

• R4 — Event journal: stream TF_TWIN_EVENTS declarativo (max_age/max_bytes) con eventos de twin/atributo/relación + fan-out WS multi-réplica.

Plans (2)

• 04-01 (Wave 1) — Declarative TF_TWIN_EVENTS stream + control-plane event publisher (values.yaml + bootstrap converge + guard coverage + internal/twinevents publisher wired into twin/attribute/relation writers incl. silent writers device_state + alarm materializer)
• 04-02 (Wave 2) — WS multi-réplica fan-out via the journal (journal consumer feeding the broadcasters, documented replace-vs-complement decision, retention guard playbook + docs)

Success Criteria

• Stream TF_TWIN_EVENTS (tf.twin.events.<tenant>.<type>.<id>) declarado en values.yaml con max_age/max_bytes y verificado por el guard de streams
• flow-core publica eventos en cada write de twin/atributo/relación del control plane (incluidos los writers hoy silenciosos: device_state, alarm materializer)
• Fan-out WS multi-réplica consumiendo el journal (decisión documentada: reemplaza o complementa los 3 broadcasters in-process)
• Retención del stream cubierta por el patrón de guards ("failed Job IS the alert")

Next Action

Run /legion:build to execute Phase 4.