PHASE 7 OBSERVABILITY MODEL — VISIBILITY WITHOUT CONTROL¶
Project: AeroDB Phase: Phase 7 — Control Plane, Admin UI, and Operator Tooling Status: AUTHORITATIVE · NON-NEGOTIABLE
1. Purpose of This Document¶
This document defines the observability model for Phase 7.
Its purpose is to ensure that:
- Operators can understand system behavior
- Failures can be investigated post‑incident
- Decisions can be reconstructed and explained
…without observability ever becoming a control mechanism.
Observability exists to illuminate reality, not to change it.
2. Foundational Principle¶
Observability must be strictly passive.
Observability:
- MAY read kernel state
- MAY read event streams
- MAY read audit logs
Observability:
- MUST NOT trigger actions
- MUST NOT influence control flow
- MUST NOT infer or recommend decisions
If observability alters behavior, it is incorrect.
3. Sources of Observability¶
Phase 7 observability is derived from authoritative sources only:
- Kernel event streams (Phases 0–6)
- Kernel state snapshots
- Phase 6 explanation artifacts
- Phase 7 audit logs
No synthetic or speculative sources are allowed.
4. Observability Surfaces¶
Phase 7 MAY expose the following surfaces.
4.1 State Views¶
- Current cluster topology
- Node roles and liveness
- Replication state and lag
- Promotion / demotion state
Rules:
- Views must reflect a single kernel snapshot
- Partial or mixed views are forbidden
4.2 Event Timelines¶
- Ordered kernel events
- Promotion state transitions
- Failover‑related decisions
Rules:
- Events must be immutable
- Ordering must be explicit
- Gaps must be visible, not hidden
4.3 Explanation Views¶
- Pre‑execution explanations
- Rejection explanations
- Invariant references
Rules:
- Explanations must be deterministic
- Explanations must reference concrete invariants
4.4 Audit Trails¶
- Operator commands
- Confirmations
- Outcomes
Rules:
- Append‑only
- Tamper‑evident
- Never editable
5. Temporal Semantics¶
Observability must respect explicit time semantics.
Rules:
- Every observation is timestamped
- Clock source must be declared
- Ordering must not rely on wall‑clock assumptions
If ordering is uncertain, it must be marked as such.
6. Observability and Failure¶
Under failure conditions:
- Observability may degrade
- Observability may become unavailable
But:
- Kernel behavior must remain unchanged
- Control plane behavior must remain unchanged
Observability failure is never a reason to retry or act.
7. Observability and Determinism¶
Given identical inputs and kernel state:
- Observability output must be identical
- Explanations must not vary
UI rendering differences must not affect semantics.
8. Forbidden Observability Patterns¶
Phase 7 MUST NOT:
- Suggest actions
- Highlight “recommended” paths
- Auto‑select defaults based on state
- Hide or smooth over failures
Observability must present facts, not guidance.
9. Privacy and Sensitivity Boundaries¶
Observability MUST respect conceptual boundaries:
- Sensitive kernel internals may be summarized
- Raw data exposure must be intentional
This document defines visibility boundaries, not access control.
10. Observability and Testing Requirements¶
The observability model MUST be tested to ensure:
- Observability never triggers control actions
- Missing observability does not alter behavior
- Explanations match kernel decisions
Tests must simulate:
- Partial observability
- Delayed event streams
- Missing logs
11. Final Statement¶
Observability exists to explain what happened, not to decide what should happen.
It must remain:
- Passive
- Deterministic
- Honest
If observability ever influences action, Phase 7 is wrong.
This observability model is authoritative.
END OF PHASE 7 OBSERVABILITY MODEL