Class: Prometheus::Client::Histogram

Inherits:
Metric
  • Object
show all
Defined in:
lib/prometheus/client/histogram.rb

Overview

A histogram samples observations (usually things like request durations or response sizes) and counts them in configurable buckets. It also provides a sum of all observed values.

Defined Under Namespace

Classes: Value

Constant Summary collapse

DEFAULT_BUCKETS =

DEFAULT_BUCKETS are the default Histogram buckets. The default buckets are tailored to broadly measure the response time (in seconds) of a network service. (From DefBuckets client_golang)

[0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1,
2.5, 5, 10].freeze

Instance Attribute Summary

Attributes inherited from Metric

#base_labels, #docstring, #name

Instance Method Summary collapse

Methods inherited from Metric

#get, #values

Methods included from UsesValueType

#value_class, #value_object

Constructor Details

#initialize(name, docstring, base_labels = {}, buckets = DEFAULT_BUCKETS) ⇒ Histogram

Offer a way to manually specify buckets

Raises:

  • (ArgumentError) 


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# File 'lib/prometheus/client/histogram.rb', line 59

def initialize(name, docstring, base_labels = {},
               buckets = DEFAULT_BUCKETS)
  raise ArgumentError, 'Unsorted buckets, typo?' unless sorted? buckets

  # Precompute both orders once per metric. Shared across all label sets
  # to avoid per-value allocation and per-observe reverse calls.
  @buckets = buckets.dup.freeze
  @buckets_descending = @buckets.reverse.freeze

  super(name, docstring, base_labels)
end

Instance Method Details

#observe(labels, value) ⇒ Object 



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# File 'lib/prometheus/client/histogram.rb', line 75

def observe(labels, value)
  label_set = label_set_for(labels)
  synchronize { @values[label_set].observe(value) }
end

#type ⇒ Object 



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# File 'lib/prometheus/client/histogram.rb', line 71

def type
  :histogram
end