histogram-3.js

'use strict';

// Histogram
// Multiple Labels
// Single Value per Label

const { register, Histogram } = require('..');

const h = new Histogram({
	name: 'test_histogram',
	help: 'Example of a histogram',
	labelNames: ['code', 'color'],
});

h.labels('200', 'blue').observe(0.4);
h.labels('200', 'blue').observe(0.6);

h.observe({ code: '200', color: 'blue' }, 0.4);

register.metrics().then(str => console.log(str));

/*
Output from metrics():

# HELP test_histogram Example of a histogram
# TYPE test_histogram histogram
test_histogram_bucket{le="0.005",code="200",color="blue"} 0
test_histogram_bucket{le="0.01",code="200",color="blue"} 0
test_histogram_bucket{le="0.025",code="200",color="blue"} 0
test_histogram_bucket{le="0.05",code="200",color="blue"} 0
test_histogram_bucket{le="0.1",code="200",color="blue"} 0
test_histogram_bucket{le="0.25",code="200",color="blue"} 0
test_histogram_bucket{le="0.5",code="200",color="blue"} 2
test_histogram_bucket{le="1",code="200",color="blue"} 3
test_histogram_bucket{le="2.5",code="200",color="blue"} 3
test_histogram_bucket{le="5",code="200",color="blue"} 3
test_histogram_bucket{le="10",code="200",color="blue"} 3
test_histogram_bucket{le="+Inf",code="200",color="blue"} 3
test_histogram_sum{code="200",color="blue"} 1.4
test_histogram_count{code="200",color="blue"} 3

*/