venv/lib/python3.12/site-packages/jupyter_server/prometheus/metrics.py

"""
Prometheus metrics exported by Jupyter Server

Read https://prometheus.io/docs/practices/naming/ for naming
conventions for metrics & labels.
"""

try:
    # Jupyter Notebook also defines these metrics.  Re-defining them results in a ValueError.
    # Try to de-duplicate by using the ones in Notebook if available.
    # See https://github.com/jupyter/jupyter_server/issues/209
    from notebook.prometheus.metrics import (
        HTTP_REQUEST_DURATION_SECONDS,
        KERNEL_CURRENTLY_RUNNING_TOTAL,
        TERMINAL_CURRENTLY_RUNNING_TOTAL,
    )

except ImportError:
    from prometheus_client import Gauge, Histogram

    HTTP_REQUEST_DURATION_SECONDS = Histogram(
        "http_request_duration_seconds",
        "duration in seconds for all HTTP requests",
        ["method", "handler", "status_code"],
    )

    TERMINAL_CURRENTLY_RUNNING_TOTAL = Gauge(
        "terminal_currently_running_total",
        "counter for how many terminals are running",
    )

    KERNEL_CURRENTLY_RUNNING_TOTAL = Gauge(
        "kernel_currently_running_total",
        "counter for how many kernels are running labeled by type",
        ["type"],
    )


__all__ = [
    "HTTP_REQUEST_DURATION_SECONDS",
    "TERMINAL_CURRENTLY_RUNNING_TOTAL",
    "KERNEL_CURRENTLY_RUNNING_TOTAL",
]