OpenTelemetry Collector Metrics Exporter for web and node

Note: This is an experimental package under active development. New releases may include breaking changes.

This module provides a metrics-exporter for OTLP (http/json) using protocol version v0.20.0.

Installation

npm install --save @opentelemetry/exporter-metrics-otlp-http

Service Name

The OpenTelemetry Collector Metrics Exporter does not have a service name configuration. In order to set the service name, use the service.name resource attribute as prescribed in the OpenTelemetry Resource Semantic Conventions. To see sample code and documentation for the traces exporter, visit the Collector Trace Exporter for web and node.

Metrics in Web

The OTLPMetricExporter in Web expects the endpoint to end in /v1/metrics.

import { MeterProvider, PeriodicExportingMetricReader } from '@opentelemetry/sdk-metrics';
import { OTLPMetricExporter } from '@opentelemetry/exporter-metrics-otlp-http';

const collectorOptions = {
  url: '<opentelemetry-collector-url>', // url is optional and can be omitted - default is http://localhost:4318/v1/metrics
  headers: {}, // an optional object containing custom headers to be sent with each request
  concurrencyLimit: 1, // an optional limit on pending requests
};
const metricExporter = new OTLPMetricExporter(collectorOptions);
const meterProvider = new MeterProvider({});

meterProvider.addMetricReader(new PeriodicExportingMetricReader({
  exporter: metricExporter,
  exportIntervalMillis: 1000,
}));

// Now, start recording data
const meter = meterProvider.getMeter('example-meter');
const counter = meter.createCounter('metric_name');
counter.add(10, { 'key': 'value' });

Metrics in Node

const { MeterProvider, PeriodicExportingMetricReader } = require('@opentelemetry/sdk-metrics');
const { OTLPMetricExporter } = require('@opentelemetry/exporter-metrics-otlp-http');
const collectorOptions = {
  url: '<opentelemetry-collector-url>', // url is optional and can be omitted - default is http://localhost:4318/v1/metrics
  concurrencyLimit: 1, // an optional limit on pending requests
};
const metricExporter = new OTLPMetricExporter(collectorOptions);
const meterProvider = new MeterProvider({});

meterProvider.addMetricReader(new PeriodicExportingMetricReader({
  exporter: metricExporter,
  exportIntervalMillis: 1000,
}));

// Now, start recording data
const meter = meterProvider.getMeter('example-meter');
const counter = meter.createCounter('metric_name');
counter.add(10, { 'key': 'value' });

Environment Variable Configuration

In addition to settings passed to the constructor, the exporter also supports configuration via environment variables:

| Environment variable | Description | |---------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | OTEL_EXPORTER_OTLP_ENDPOINT | The endpoint to send metrics to. This will also be used for the traces exporter if OTEL_EXPORTER_OTLP_TRACES_ENDPOINT is not configured. By default http://localhost:4318 will be used. /v1/metrics will be automatically appended to configured values. | | OTEL_EXPORTER_OTLP_METRICS_ENDPOINT | The endpoint to send metrics to. By default https://localhost:4318/v1/metrics will be used. v1/metrics will not be appended automatically and has to be added explicitly. | | OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE | The exporters aggregation temporality preference. Valid values are cumulative, delta, and lowmemory. cumulative selects cumulative temporality for all instrument kinds. delta selects delta aggregation temporality for Counter, Asynchronous Counter and Histogram instrument kinds, and selects cumulative aggregation for UpDownCounter and Asynchronous UpDownCounter instrument kinds. lowmemory selects delta aggregation temporality for Counter and Histogram instrument kinds, and selects cumulative aggregation for UpDownCounter, Asynchronous Counter and Asynchronous UpDownCounter instrument kinds. By default cumulative is used. |

Settings configured programmatically take precedence over environment variables. Per-signal environment variables take precedence over non-per-signal environment variables.

Running opentelemetry-collector locally to see the metrics

1. Go to examples/otlp-exporter-node
2. Follow the instructions there to observe the metrics.

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 in GitHub Discussions
• For exporting metrics via gRPC please check exporter-metrics-otlp-grpc
• For exporting metrics via protobuf please check exporter-metrics-otlp-proto

License

Apache 2.0 - See LICENSE for more information.