@opentelemetry/metrics

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 { MeterProvider } = require('@opentelemetry/metrics');

// Initialize the Meter to capture measurements in various ways.
const meter = new MeterProvider().getMeter('your-meter-name');

const counter = meter.createCounter('metric_name', {
  description: 'Example of a counter'
});

const labels = { pid: process.pid };

// Create a BoundInstrument associated with specified label values.
const boundCounter = counter.bind(labels);
boundCounter.add(10);

Observable

Choose this kind of metric when only last value is important without worry about aggregation

const { MeterProvider, MetricObservable } = require('@opentelemetry/metrics');

// Initialize the Meter to capture measurements in various ways.
const meter = new MeterProvider().getMeter('your-meter-name');

const observer = meter.createObserver('metric_name', {
  description: 'Example of a observer'
});

function getCpuUsage() {
  return Math.random();
}

const metricObservable = new MetricObservable();

observer.setCallback((observerResult) => {
  // synchronous callback
  observerResult.observe(getCpuUsage, { pid: process.pid, core: '1' });
  // asynchronous callback
  observerResult.observe(metricObservable, { pid: process.pid, core: '2' });
});

// simulate asynchronous operation
setInterval(()=> {
  metricObservable.next(getCpuUsage());
}, 2000)

See examples/prometheus for a short example.

Value Recorder

ValueRecorder is a non-additive synchronous instrument useful for recording any non-additive number, positive or negative. Values captured by ValueRecorder.record(value) are treated as individual events belonging to a distribution that is being summarized. ValueRecorder should be chosen either when capturing measurements that do not contribute meaningfully to a sum, or when capturing numbers that are additive in nature, but where the distribution of individual increments is considered interesting.

Useful links

• For more information on OpenTelemetry, visit: https://opentelemetry.io/
• For more about OpenTelemetry JavaScript: https://github.com/open-telemetry/opentelemetry-js
• For help or feedback on this project, join us on gitter

License

Apache 2.0 - See LICENSE for more information.

Changelog

0.9.0

:boom: Breaking Change

• opentelemetry-api, opentelemetry-exporter-prometheus, opentelemetry-metrics
  • #1120 feat: add the UpDownCounter instrument (@mayurkale22)
  • #1126 feat!: remove label keys as they are no longer part of the spec (@naseemkullah)
• opentelemetry-api, opentelemetry-metrics
  • #1117 chore: rename meaure to value recorder (@dyladan)
• opentelemetry-api, opentelemetry-core, opentelemetry-tracing
  • #1058 feat: spec compliant sampling result support (@legendecas)

:rocket: (Enhancement)

• Other
  • #1181 feat: add node-plugins-all package (@dyladan)
• opentelemetry-plugin-fetch, opentelemetry-plugin-xml-http-request, opentelemetry-web
  • #1121 chore: adding plugin-fetch and example (@obecny)
• opentelemetry-node
  • #1153 feat: add OPENTELEMETRY_NO_PATCH_MODULES (@markwolff)
  • #1151 chore(todo): add missing span sampling test (@markwolff)
• opentelemetry-exporter-jaeger
  • #965 feat(opentelemetry-exporter-jaeger): http sender (@leonardodalcin)
• opentelemetry-exporter-zipkin
  • #1138 feat(opentelemetry-js): infer zipkin service name from resource (@rezakrimi)
• opentelemetry-plugin-xml-http-request
  • #1133 fix(plugin-xml-http-request): support sync requests (@johnbley)
• opentelemetry-metrics
  • #1145 chore: creating new metric kind (@obecny)
• opentelemetry-exporter-collector
  • #1204 feat: collector exporter custom headers and metadata (@mwear)
• opentelemetry-exporter-zipkin
  • #1202 Adds possibility to set headers to zipkin exporter (@obecny)

:bug: (Bug Fix)

• opentelemetry-exporter-collector
  • #1197 fix(exporter-collector): default endpoint for node and browser (@davidwitten)
• opentelemetry-context-zone-peer-dep
  • #1209 chore: fixing zone from which to fork a new zone (@obecny)

:sparkles: (Feature)

• opentelemetry-semantic-conventions
  • #1160 refactor(attributes): move enums to @opentelemetry/semantic-conventions (@markwolff)

:books: (Refine Doc)

• Other
  • #1192 Fix_typo (@shivkanya9146)
  • #1147 ci: lint markdown files (@naseemkullah)
  • #1142 chore: template prometheus endpoint in examples rather than hardcode (@naseemkullah)
  • #1217 chore: fix markdown linting and add npm script (@dyladan)

Committers: 13

• David W. (@davidwitten)
• Bartlomiej Obecny (@obecny)
• Daniel Dyla (@dyladan)
• Mark Wolff (@markwolff)
• Mayur Kale (@mayurkale22)
• Naseem (@naseemkullah)
• Valentin Marchaud (@vmarchaud)
• legendecas (@legendecas)
• Shivkanya Andhare (@shivkanya9146)
• Leonardo Dalcin (@leonardodalcin)
• @rezakrimi
• John Bley (@johnbley)
• Matthew Wear (@mwear)