Prometheus.ex v1.0.0-alpha3 Prometheus.Metric.Summary

Summary metric, to track the size of events.

Example use cases for Summaries:

Response latency;
Request size;
Response size.

Example:

defmodule MyProxyInstrumenter do

  use Prometheus.Metric

  ## to be called at app/supervisor startup.
  ## to tolerate restarts use declare.
  def setup() do
    Summary.declare([name: :request_size_bytes,
                     help: "Request size in bytes."])

    Summary.declare([name: :response_size_bytes,
                     help: "Response size in bytes."])
  end

  def observe_request(size) do
    Summary.observe([name: :request_size_bytes], size)
  end

  def observe_response(size) do
    Summary.observe([name: :response_size_bytes], size)
  end
end

Summary

Macros

declare(spec)

Creates a summary using spec. Summary cannot have a label named “quantile”

dobserve(spec, amount \\ 1)

Observes the given amount. If amount happened to be a float number even one time(!) you shouldn’t use observe/2 after dobserve

new(spec)

Creates a summary using spec. Summary cannot have a label named “quantile”

observe(spec, amount \\ 1)

Observes the given amount

observe_duration(spec, fun)

Observes the amount of microseconds spent executing fun

reset(spec)

Resets the value of the summary identified by spec

value(spec)

Returns the value of the summary identified by spec. If there is no summary for given labels combination, returns :undefined

Macros

declare(spec)

Creates a summary using spec. Summary cannot have a label named “quantile”.

If a summary with the same spec exists returns false.

Raises Prometheus.Error.MissingMetricSpecKey if required spec key is missing.
Raises Prometheus.Error.InvalidMetricName if metric name is invalid.
Raises Prometheus.Error.InvalidMetricHelp if help is invalid.
Raises Prometheus.Error.InvalidMetricLabels if labels isn’t a list.
Raises Prometheus.Error.InvalidMetricName if label name is invalid.

dobserve(spec, amount \\ 1)

Observes the given amount. If amount happened to be a float number even one time(!) you shouldn’t use observe/2 after dobserve.

Raises Prometheus.Error.InvalidValue exception if amount isn’t a positive integer.
Raises Prometheus.Error.UnknownMetric exception if a summary for spec can’t be found.
Raises Prometheus.Error.InvalidMetricArity exception if labels count mismatch.

new(spec)

Creates a summary using spec. Summary cannot have a label named “quantile”.

observe(spec, amount \\ 1)

Observes the given amount.

observe_duration(spec, fun)

Observes the amount of microseconds spent executing fun.

Raises Prometheus.Error.UnknownMetric exception if a summary for spec can’t be found.
Raises Prometheus.Error.InvalidMetricArity exception if labels count mismatch.

reset(spec)

Resets the value of the summary identified by spec.

Raises Prometheus.Error.UnknownMetric exception if a summary for spec can’t be found.
Raises Prometheus.Error.InvalidMetricArity exception if labels count mismatch.

value(spec)

Returns the value of the summary identified by spec. If there is no summary for given labels combination, returns :undefined.

Raises Prometheus.Error.UnknownMetric exception if a summary for spec can’t be found.
Raises Prometheus.Error.InvalidMetricArity exception if labels count mismatch.