aituner/docs/intervention-response-v3-two-load-protocol-20260714.md

Phase-aware telemetry intervention-response v3 protocol

Status: FROZEN AFTER A NON-COMPARATIVE OPERATIONAL FAILURE AND BEFORE V3 RUNS.

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

Why v2 was invalid

The first v2 session completed the 300-second arrival windows at 1.5 and 2.125 requests/s/GPU. At 3.125 requests/s/GPU, MNS=16 could not drain the admitted requests before the 450-second client timeout. The session produced no result and no MNS=64 action endpoint was run. V2 is therefore an invalid operational attempt, not evidence for or against the telemetry hypothesis.

This failure was observed before any MNS action comparison. V3 excludes only the unmeasurable overload point and reruns every retained point on fresh servers; it does not reuse the completed v2 low/mid results.

Question and hypothesis

Question: after enough replay time for queue, batch, and KV state to develop, does an MNS intervention create telemetry responses that exceed workload-repeat noise, and does any such response predict whether the intervention repairs the full-run SLO outcome better than external prefix outcomes alone?

Hypothesis: increasing MNS from 16 to 64 has little value at the 1.5 requests/s/GPU control load but can repair the 2.125 requests/s/GPU pressure load. Queue, running-set, batch, or KV telemetry should expose the difference at stable replay phases. Label balance is an assumption to test, not a fact.

Frozen setup

• Solo placement on dash0 GPU 0-3: 4 NVIDIA H20 GPUs, Qwen3-30B-A3B, patched vLLM 0.24.1.dev3+opprof, fixed TP=4.
• Action: MNS 16 -> 64; all other engine and workload parameters fixed.
• Workload: chat_w20260312_1000, replay-time scale 0.5, hence 300 seconds.
• Loads per GPU: 1.5 control and 2.125 pressure requests/s. The failed 3.125 overload point is excluded from V3 and retained only as a failure artifact.
• Three disjoint request bands. Each MNS action pair has exact request, arrival, and input-length hashes. Endpoint order is A/B, B/A, A/B; load order is low/mid, mid/low, low/mid.
• Every session starts a fresh server, then runs the accepted 16-request long warm-up and bounded burn-in before measured runs.
• SLO-unrecoverable early stop is disabled. Measured results must cover the full 300-second arrival window and must not be early-stopped.
• Cumulative checkpoints are 10%, 25%, 50%, 75%, and 100%; non-overlapping quarter blocks are also reported.
• A Layer-1 interval is complete only if timestamps are monotonic and its start, end, and maximum internal record gaps are each at most one second.
• Incremental V3 cap is the unused portion of the original 8 H20-hour cap. The exact prior cost and V3 cap are machine-recorded in the manifest.

Frozen gates

Data validity requires six uncensored sessions, six action pairs, eight same-config repeat pairs, exact action-pair hashes, full request accounting, zero Layer-1 drops, continuous coverage, all stream/footer invariants, no co-resident compute process, idle GPUs before and after sessions, nonnegative counters, bounded ratios, non-identical per-config state, and monotonic request coverage across checkpoints. Any red flag stops analysis.

Mechanism evidence requires at least two telemetry features to exceed the unchanged v1 repeat-noise thresholds at the same pair of adjacent checkpoints. Those features must have a direction consistent in both retained load regimes.

Decision evidence additionally requires at least two positive and two negative full-run action-efficacy labels, valid leave-one-repetition-out folds, and at least one phase-stable mechanism feature whose balanced accuracy is at least 0.75 and at least 0.15 above the best external prefix-outcome feature at two adjacent predeclared checkpoints from 25% onward.

V3 remains a development mechanism pilot. Even OPEN_E2E_POLICY_TEST opens a held-out tuning-policy experiment; it is not itself a paper performance claim.