Schema.ai· vLLM
vLLM official site ↗vLLM v0.23.0API up

In vLLM v0.23.0, vllm:num_preemptions increments from IterationStats.num_preempted_reqs, which is increased when engine-core events mark requests as preempted.

MetricvLLM v0.23.0confidence: highverified 14 min agoverified-code

Metric

num_preemptions

Applies when

V1 engine-core preemption eventsPrometheusStatLogger metrics publisher

Evidence

vLLM v0.23.0 v1 metrics stats.py(vllm/v1/metrics/stats.py:419-426)
definesprimarysource_codecode_introspection
vLLM v0.23.0 v1 metrics loggers.py(vllm/v1/metrics/loggers.py:1149-1150)
definesprimarysource_codecode_introspection

Does not establish

  • that every preemption is caused by KV cache pressure
  • which config knob should be changed
  • the operational severity of a given counter value

Guards

  • vllm_version = v0.23.0
  • metric_name = vllm:num_preemptions
  • runtime_component = scheduler

Freshness

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