class Prometheus::Histogram

Overview

A Histogram samples observations (usually things like request durations or response sizes) and counts them in configurable buckets.

Use a Histogram to track size distributions, such as:

Request duration
Response sizes
Queue length variations

Example:

# Create with custom buckets
histogram = Histogram.new(
  "response_time",
  "Response time in seconds",
  [0.1, 0.5, 1.0, 2.0, 5.0]
)

# Observe values
histogram.observe(0.25)

Histograms track:

Count per bucket (number of values <= bucket upper bound)
Total sum of all observed values
Count of all observed values

Defined in:

metrics.cr

Constructors

.new(name : String, help : String, buckets : Array(Float64), labels = Labels.new)

Instance Method Summary

#collect(io : IO) : Nil
#collect : Array(Sample)
#observe(value : Number, labels : Labels | Nil = nil)
#type : String

Instance methods inherited from class `Prometheus::Metric`

, , , ,

Constructor methods inherited from class `Prometheus::Metric`

Constructor Detail

def self.new(name : String, help : String, buckets : Array(Float64), labels = Labels.new) #

Instance Method Detail

def collect(io : IO) : Nil #

def collect : Array(Sample) #

def observe(value : Number, labels : Labels | Nil = nil) #

def type : String #

prometheus