Class Summary

prometheus_client/metrics.py:505–572

A Summary tracks the size and number of events. Example use cases for Summaries: - Response latency - Request size Example for a Summary: from prometheus_client import Summary s = Summary('request_size_bytes', 'Request size (bytes)') s.observe(512) # Obse

class Summary(MetricWrapperBase):
    """A Summary tracks the size and number of events.

    Example use cases for Summaries:
    - Response latency
    - Request size

    Example for a Summary:

        from prometheus_client import Summary

        s = Summary('request_size_bytes', 'Request size (bytes)')
        s.observe(512)  # Observe 512 (bytes)

    Example for a Summary using time:

        from prometheus_client import Summary

        REQUEST_TIME = Summary('response_latency_seconds', 'Response latency (seconds)')

        @REQUEST_TIME.time()
        def create_response(request):
          '''A dummy function'''
          time.sleep(1)

    Example for using the same Summary object as a context manager:

        with REQUEST_TIME.time():
            pass  # Logic to be timed
    """
    _type = 'summary'
    _reserved_labelnames = ['quantile']

    def _metric_init(self) -> None:
        self._count = values.ValueClass(self._type, self._name, self._name + '_count', self._labelnames,
                                        self._labelvalues, self._documentation)
        self._sum = values.ValueClass(self._type, self._name, self._name + '_sum', self._labelnames, self._labelvalues, self._documentation)
        self._created = time.time()

    def observe(self, amount: float) -> None:
        """Observe the given amount.

        The amount is usually positive or zero. Negative values are
        accepted but prevent current versions of Prometheus from
        properly detecting counter resets in the sum of
        observations. See
        https://prometheus.io/docs/practices/histograms/#count-and-sum-of-observations
        for details.
        """
        self._raise_if_not_observable()
        self._count.inc(1)
        self._sum.inc(amount)

    def time(self) -> Timer:
        """Time a block of code or function, and observe the duration in seconds.

        Can be used as a function decorator or context manager.
        """