- Delete unreachable best_needs_push block in _handle_combined and the
four orphaned helpers (_handle_cached_prefill_offload,
_handle_direct_read_offload, _query_bootstrap_hit,
_get_bootstrap_client). Their only caller was the retired PUSH gate;
see REPORT §3.9 errata for the rejected experiments (cc6e562, 4c583f2).
- Extract pick_instance_unified_hybrid as a pure function returning
(chosen, idx, decision_dict). The decision dict carries the review #7
breakdown fields (decision, affinity_idx/chosen_idx, cache_hit/ratio,
avg_num_requests, fallback_score, tie_break_used).
- Add LMetric-fallback tie-breaker (primary score, then new_uncached,
num_requests, round-robin) so new sessions don't all pin to inst 0
when BS=0 across the board.
- Drop the lmetric-policy affinity write so --policy lmetric stays
affinity-free per review #3.
- Mark --max-offload-inflight / --offload-mode / --cache-gate-ratio /
--decode-iteration-s as [DEPRECATED] in --help; flags remain accepted
so scripts/bench.sh and legacy launchers don't break.
- Revert uncommitted overload_factor 2.0->1.5 default; H7 sweep already
rejected this knob (within noise). Future sweeps should go via CLI.
Tests: add 6 hybrid-policy tests in tests/test_proxy_pick.py covering
affinity-hit, overload break, low-cache fallback, tie-break rotation,
lmetric purity, and breakdown field shape. 19/19 pass.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- Replace mutable module constants (HEAVY_THRESHOLD/OVERLOAD_FACTOR/
MAX_OFFLOAD_INFLIGHT/PREFILL_THROUGHPUT/RDMA_OVERHEAD_S/
CACHE_CAPACITY_BLOCKS) with a Settings dataclass + SETTINGS singleton.
__main__ now mutates SETTINGS so CLI overrides survive even when the
module is imported as a library (e.g. by tests/) (D5).
- Add --max-offload-inflight CLI flag (M3) and read it from SETTINGS.
- Add --cache-gate-ratio CLI flag and a real gate before the cost-model
branch: if cache_hit/input_length < ratio, mark cache_gate_REASON and
fall back to colocated. cache_ratio is no longer a write-only field
(B4).
- P candidate selection penalises instances already running offloaded
HEAVY prefills, so back-to-back HEAVY requests don't pile onto the
same P (M2).
- bench.sh forwards --max-offload-inflight / --cache-gate-ratio to the
proxy.
- Tests cover SETTINGS knobs + the heavy_threshold-driven P-offload
penalty.
- tests/test_metrics.py asserts the new linear-interp _percentile against
hand-computed expected values (single value, two-value interpolation,
endpoints, numpy-equivalent linear default, on-integer rank).
- tests/test_proxy_pick.py exercises InstanceState LRU eviction and
move-to-end on hit, plus session-affinity stickiness, the overload
fallback, the active_p_offloads penalty, and lmetric scoring. The
proxy is loaded by file path with stub fastapi/uvicorn/httpx modules
so the suite runs without the FastAPI server deps installed.
- pyproject.toml gets a hatchling wheel target and a [tool.pytest]
section so `uv run --extra dev pytest` works out of the box.
