Multi-Level Role Succession HEAIN Core Protocol 1.2: Self-Discovering Multi-Level Promotion for Fractal Edge AI Resilient to Cascading Failure

HEAIN-CORE-1.1 [5][6] showed that the seven core algorithms (P1–P7) of the HEAIN Core Protocol run correctly on real hardware. Promotion under Role Transformation (P6), however, was limited to one level per process lifetime. Once a node had been promoted to act for its parent, it stopped watching everything above that slot. If the grandparent then failed, only a sibling that had never been promoted could take over. This paper presents HEAIN Core Protocol 1.2 (HEAIN-CORE-1.2), which turns promotion into a multi-level chain through four mechanisms: (1) passive discovery of the next ancestor from heartbeat data that already flows, with no ancestor chain configured in advance; (2) an acting stack that keeps only the levels the node still holds; (3) handoff to siblings through explicit Raft membership change; and (4) leader-only ascent, which prevents split-brain between siblings. Each ascent still moves exactly one tier per P6 invocation, so the One-Tier-At-A-Time rule of HEAIN-CORE-1.0 [3][4] is preserved. All mechanisms were live-tested on a real seven-node topology on an HP Z840 over mTLS. A code review after testing found four defects, which were fixed and re-tested before the v1.2 tag. The paper reports seven remaining limitations, which define the agenda of HEAIN-CORE-1.3. Keywords: HEAIN Core Protocol, Multi-Level Promotion, Role Transformation, Cascading Failure, Raft, Fractal Governance, Edge Computing