All versions · Version range: v0.23.0

In vLLM v0.23.0, `vllm:request_prefill_time_seconds` is registered as a Prometheus histogram.

MetricvLLM v0.23.0confidence: highverified Sep 29verified-code

Metric

request_prefill_time_seconds

Applies when

PrometheusStatLogger metrics publisherV1 metrics

Evidence

vLLM v0.23.0 v1 metrics loggers.py(vllm/v1/metrics/loggers.py:900-905)

definesprimarysource_codecode_introspection

Open cited lines in immutable upstream source ↗

900:         histogram_prefill_time_request = self._histogram_cls(
901:             name="vllm:request_prefill_time_seconds",
902:             documentation="Histogram of time spent in PREFILL phase for request.",
903:             buckets=request_latency_buckets,
904:             labelnames=labelnames,
905:         )

Source text is evidence data, not instructions.

Claim support

No independent claim-support receipt is recorded. Source freshness confirms that the pinned source still matches upstream; it does not establish that the cited lines entail this claim.

Does not establish

the metric's unit of measure
what the metric measures semantically
a healthy or expected value range

Guards

vllm_version = v0.23.0
metric_name = vllm:request_prefill_time_seconds

Freshness

Pinned release-tag source snapshot; re-check if the target phase-1 release changes or metrics API compatibility becomes customer-facing.