vllm.v1.metrics.prometheus

_prometheus_multiproc_dir module-attribute

_prometheus_multiproc_dir: Optional[TemporaryDirectory] = (
    None
)

logger module-attribute

logger = init_logger(__name__)

get_prometheus_registry

get_prometheus_registry()

Get the appropriate prometheus registry based on multiprocessing configuration.

Returns:

Name	Type	Description
Registry		A prometheus registry

Source code in vllm/v1/metrics/prometheus.py

def get_prometheus_registry():
    """Get the appropriate prometheus registry based on multiprocessing 
    configuration.

    Returns:
        Registry: A prometheus registry
    """
    if os.getenv("PROMETHEUS_MULTIPROC_DIR") is not None:
        logger.debug("Using multiprocess registry for prometheus metrics")
        registry = CollectorRegistry()
        multiprocess.MultiProcessCollector(registry)
        return registry

    return REGISTRY

setup_multiprocess_prometheus

setup_multiprocess_prometheus()

Set up prometheus multiprocessing directory if not already configured.

Source code in vllm/v1/metrics/prometheus.py

def setup_multiprocess_prometheus():
    """Set up prometheus multiprocessing directory if not already configured.

    """
    global _prometheus_multiproc_dir

    if "PROMETHEUS_MULTIPROC_DIR" not in os.environ:
        # Make TemporaryDirectory for prometheus multiprocessing
        # Note: global TemporaryDirectory will be automatically
        # cleaned up upon exit.
        _prometheus_multiproc_dir = tempfile.TemporaryDirectory()
        os.environ["PROMETHEUS_MULTIPROC_DIR"] = _prometheus_multiproc_dir.name
        logger.debug("Created PROMETHEUS_MULTIPROC_DIR at %s",
                     _prometheus_multiproc_dir.name)
    else:
        logger.warning("Found PROMETHEUS_MULTIPROC_DIR was set by user. "
                       "This directory must be wiped between vLLM runs or "
                       "you will find inaccurate metrics. Unset the variable "
                       "and vLLM will properly handle cleanup.")

shutdown_prometheus

shutdown_prometheus()

Shutdown prometheus metrics.

Source code in vllm/v1/metrics/prometheus.py

def shutdown_prometheus():
    """Shutdown prometheus metrics."""

    path = _prometheus_multiproc_dir
    if path is None:
        return
    try:
        pid = os.getpid()
        multiprocess.mark_process_dead(pid, path)
        logger.debug("Marked Prometheus metrics for process %d as dead", pid)
    except Exception as e:
        logger.error("Error during metrics cleanup: %s", str(e))

unregister_vllm_metrics

unregister_vllm_metrics()

Unregister any existing vLLM collectors from the prometheus registry.

This is useful for testing and CI/CD where metrics may be registered multiple times across test runs.

Also, in case of multiprocess, we need to unregister the metrics from the global registry.

Source code in vllm/v1/metrics/prometheus.py

def unregister_vllm_metrics():
    """Unregister any existing vLLM collectors from the prometheus registry.

    This is useful for testing and CI/CD where metrics may be registered
    multiple times across test runs.

    Also, in case of multiprocess, we need to unregister the metrics from the 
    global registry.
    """
    registry = REGISTRY
    # Unregister any existing vLLM collectors
    for collector in list(registry._collector_to_names):
        if hasattr(collector, "_name") and "vllm" in collector._name:
            registry.unregister(collector)