Three fixes from the B3 audit:
1) joined_analysis.hotspot_index used sorted[n//2] as median, which
returns the ~60th percentile for n=8 (even-length). Systematically
under-states the hotspot index. Recomputed values:
lmetric 2.238 -> 2.253 (+0.7%)
load_only 1.140 -> 1.294 (+13.5%)
sticky 2.349 -> 2.728 (+16.1%)
unified 3.350 -> 3.667 (+9.5%)
capped 1.937 -> 2.020 (+4.3%)
Qualitative ranking preserved; "capped only modestly reduces hotspot"
story holds with ~10% drop instead of the previously reported 13%.
Added test_hotspot_index_uses_true_median_for_even_n to lock in the
fix.
2) b3_analyze.sh's pct() helper used floor-indexed percentile
sorted[int(p*(n-1))], inconsistent with metrics._percentile and
joined_analysis._percentile which both use linear interpolation.
Now matches.
3) b3_sweep.sh's capped step called run_policy "capped", but the
proxy's argparse has no "capped" choice, so the hot-sweep variant
would have crashed on this step. The actual capped data was
produced via b3_isolated_policy.sh with --policy lmetric. Replace
the broken inline call with an explicit launch_proxy lmetric +
inline replayer block so the sweep script matches the data path
it documents.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Smoke validation on dash0 surfaced three real bugs that broke
interference and failure-attribution labels end-to-end:
1. endpoint_url in metrics is the proxy URL (e.g. http://h:9200);
the vLLM worker URL lives in breakdown's routed_to. The
interference index and label path were taking endpoint_url first,
so every request looked routed to a non-existent worker and the
overlap counter stayed at zero.
2. _normalize_worker hard-coded base port 8000, so a smoke run on
port 9100 resolved to engine_1100 instead of engine_0. Added a
--worker-map URL=engine_id CLI flag and _resolve_worker() that
prefers the explicit map and falls back to the heuristic.
3. vLLM rewrites the per-step rid as cmpl-<proxy_id>-<i>-<hash>, so
the str equality check between per_req rid and our proxy
request_id never matched -> every prefill step looked like
"other request prefill", which would have flipped overlap to
100%. Added _vllm_rid_matches() that strips the cmpl-/chatcmpl-
prefix.
After the fix, the same smoke run reports interference_index = 22.9
across 24 overlap / 6 clean requests on a single instance, which is
the expected shape for serial dispatch into a cold engine.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
New analysis/characterization/joined_analysis.py joins replayer
metrics.jsonl + proxy breakdown.json + worker_state.jsonl by
request_id, plus engine_*.jsonl by worker_id, and emits:
- joined.jsonl per-request merged record
- reuse_decomposition.json real intra/cross/shared classification
using session_id + hash_ids + cached_tokens
- interference_index.json TPOT_p90(same-worker prefill overlap)
/ TPOT_p90(clean), per Batch 2
- hotspot_index.json max/median worker TTFT-p90, per Batch 3
- failure_label.jsonl per-slow-request cause label, per Batch 5
- failure_breakdown.json label histogram
- window_summary.json SRR warmup/steady/drain aggregates
Closes the analyzer side of Phase A; replaces the
status: unavailable placeholders the existing scaffold emits when
join sources are missing.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
