aituner/docs/intervention-response-v2-phase-aware-protocol-20260714.md

Phase-aware telemetry intervention-response v2 protocol

Status: FROZEN BEFORE THE SYSTEMATIC 10% DECILE AUDIT.

Date: 2026-07-14 (Asia/Singapore).

Correction to v0/v1

The 5/10-second analyses tested an ultra-early verifier. They did not test whether telemetry observed after the engine has developed queue, batch, and KV state can guide tuning. The P1 replay lasts 60 seconds after time scaling, and the 5/10-second prefixes contain only a small fraction of its requests.

V2 therefore replaces absolute cutoffs with replay phase. The old audits and their negative decisions remain immutable, but their claim is narrowed to the first 5/10 seconds.

Historical corrective audit

The historical audit is development-only and cannot become confirmatory after the horizon concern was observed.

• Infer each trial's intended replay duration as selected requests divided by offered requests per second. All trials must agree.
• Find every complete 10% replay decile supported by every trial. Analyze all such deciles; selecting only the best horizon is forbidden.
• At each decile report both:
  • cumulative state from replay start to the checkpoint; and
  • the non-overlapping 10%-wide state block ending at the checkpoint.
• Report admitted/completed request coverage, response-versus-repeat statistics, telemetry versus external-outcome efficacy, and per-feature trajectory drift.
• Reuse the frozen v1 action and repeat pairs and the frozen response and incremental-efficacy thresholds. These thresholds are descriptive in V2; passing one post-hoc horizon does not open a contribution claim.

If early stopping prevents complete observation of the replay phases, the historical decision is REQUIRES_UNCENSORED_PHASE_AWARE_PILOT, independent of which early decile looks best.

Uncensored matched pilot

The pilot is a mechanism gate, not paper evidence.

• Hardware/engine/model: solo placement on dash0, 4 NVIDIA H20 GPUs, patched vLLM 0.24.1.dev3+opprof, Qwen3-30B-A3B, fixed TP=4.
• Action: MNS 16 -> 64; topology, model, engine build, workload, arrival sequence, offered load, and all other settings remain fixed.
• Workload: chat_w20260312_1000 at replay-time scale 0.5, hence 300 seconds.
• Offered loads per GPU: 1.5, 2.125, and 3.125 requests/s. These supply a low control and the two already-observed P1 pressure regimes.
• Repetitions: three disjoint session bands, exact request sequence matched across action endpoints. Endpoint order alternates A/B, B/A, A/B; load order is counter-rotated across repetitions.
• A fresh server receives the accepted long-request warm-up and a bounded burn-in before each measured session.
• SLO-unrecoverable early stop is disabled. Every run must observe the full 300-second arrival window; a separate 360-second safety deadline may mark a run invalid but cannot manufacture a full-run label.
• Cumulative checkpoints: 10%, 25%, 50%, 75%, and 100%, or 30/75/150/225/300 seconds. Quarter blocks are analyzed separately from cumulative means.
• A measured Layer-1 interval is complete only when its start-boundary, end-boundary, and maximum internal record gaps are each at most one second; timestamps must be monotonic.
• Placement is serialized. Co-location remains forbidden because Phase 6 observed material co-location-induced outcome shifts.
• Hard cap: 8 H20-hours including startup, warm-up, burn-in, invalid attempts, and cleanup.

Gates

Data validity requires complete 300-second Layer-1 coverage, zero dropped records, exact request/arrival/length hashes across action endpoints, monotonic timestamps, full request accounting, idle GPUs before and after each session, and no co-resident GPU process.

Mechanism evidence requires at least two telemetry features whose matched action response exceeds same-config repeat noise at the same pair of consecutive checkpoints under the unchanged v1 response thresholds. Those features must also have a consistent direction in at least two of the three load regimes.

Decision evidence additionally requires both action-efficacy classes and at least one of the phase-stable mechanism features to reach leave-one-repetition-out balanced accuracy at least 0.75 and exceed the best external prefix outcome by at least 0.15 at two adjacent predeclared checkpoints from 25% onward. Without label balance the pilot can adjudicate mechanism evidence only.

No H20 run is launched if the local analyzer/tests, manifest preflight, GPU probe, command dry-run, projected cost, or cleanup plan fails.