All versions · Version range: v0.23.0

In vLLM v0.23.0, `vllm:kv_block_reuse_gap_seconds` is registered as a Prometheus histogram when `observability_config.kv_cache_metrics=True`.

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

Metric

kv_block_reuse_gap_seconds

Applies when

PrometheusStatLogger metrics publisherV1 metricsobservability_config.kv_cache_metrics=True

Evidence

vLLM v0.23.0 v1 metrics loggers.py(vllm/v1/metrics/loggers.py:987-997)

definesprimarysource_codecode_introspection

Open cited lines in immutable upstream source ↗

987:             histogram_kv_block_reuse_gap = self._histogram_cls(
988:                 name="vllm:kv_block_reuse_gap_seconds",
989:                 documentation=(
990:                     "Histogram of time gaps between consecutive KV cache block "
991:                     "accesses. Only the most recent accesses are recorded "
992:                     "(ring buffer). Sampled metrics (controlled by "
993:                     "--kv-cache-metrics-sample)."
994:                 ),
995:                 buckets=kv_cache_residency_buckets,
996:                 labelnames=labelnames,
997:             )

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:kv_block_reuse_gap_seconds

Freshness

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