OpenTelemetry Metrics SDK
OpenTelemetry metrics allow a user to collect data and export it to a metrics backend like Prometheus.
Installation
npm install --save @opentelemetry/metrics
Usage
Counter
Choose this kind of metric when the value is a quantity, the sum is of primary interest, and the event count and value distribution are not of primary interest. Counters are defined as Monotonic = true
by default, meaning that positive values are expected.
const { MeterRegistry } = require('@opentelemetry/metrics');
const meter = new MeterRegistry().getMeter('your-meter-name');
const counter = meter.createCounter('metric_name', {
labelKeys: ["pid"],
description: "Example of a counter"
});
const labels = meter.labels({ pid: process.pid });
const boundCounter = counter.bind(labels);
boundCounter.add(10);
Gauge
Gauge metrics express a pre-calculated value. Generally, this kind of metric should be used when the metric cannot be expressed as a sum or because the measurement interval is arbitrary. Use this kind of metric when the measurement is not a quantity, and the sum and event count are not of interest. Gauges are defined as Monotonic = false
by default, meaning that new values are permitted to make positive or negative changes to the gauge. There is no restriction on the sign of the input for gauges.
const { MeterRegistry } = require('@opentelemetry/metrics');
const meter = new MeterRegistry().getMeter('your-meter-name');
const gauge = meter.createGauge('metric_name', {
labelKeys: ["pid"],
description: "Example of a gauge"
});
const labels = meter.labels({ pid: process.pid });
const boundGauge = gauge.bind(labels);
boundGauge.set(10);
See examples/prometheus for a short example.
Measure
Work in progress
Useful links
License
Apache 2.0 - See LICENSE for more information.