The first B2 run produced metrics with ttft_s=null/tpot_s=null for
every decode request because the OpenAI-style payload did not set
return_token_ids: true, and the parser only inspected
choices[0].token_ids. With token_ids missing the loop skipped every
chunk, so no per-token timestamps were captured and the aggregator
returned interference_index=null on all 10 cells.
Fix:
- send return_token_ids: true in the payload (matches replayer.replay)
- also accept text-delta chunks as token signals (fallback for
servers that drop token_ids despite the flag)
vLLM engine_state was fine; only the load-gen metric capture was
broken.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Gahow Wang
b9f324f2e6