Workiva/opentelemetry-dart

OpenTelemetry for Dart

This repository is the Dart implementation of the OpenTelemetry project. All contributions and designs should follow the OpenTelemetry specification.

Project Status

Signal	Status
Traces	Beta
Metrics	Alpha
Logs	Unimplemented

Getting Started

This section will show you how to initialize the OpenTelemetry SDK, capture a span, and propagate context.

Initialize the OpenTelemetry SDK

import 'package:opentelemetry/sdk.dart'
    show
        BatchSpanProcessor,
        CollectorExporter,
        ConsoleExporter,
        SimpleSpanProcessor,
        TracerProviderBase;
import 'package:opentelemetry/api.dart'
    show registerGlobalTracerProvider, globalTracerProvider;

void main(List<String> args) {
  final tracerProvider = TracerProviderBase(processors: [
    BatchSpanProcessor(
        CollectorExporter(Uri.parse('https://my-collector.com/v1/traces'))),
    SimpleSpanProcessor(ConsoleExporter())
  ]);

  registerGlobalTracerProvider(tracerProvider);
  final tracer = globalTracerProvider.getTracer('instrumentation-name');
}

Capture a Span

import 'package:opentelemetry/api.dart' show StatusCode, globalTracerProvider;

void main(List<String> args) {
  final tracer = globalTracerProvider.getTracer('instrumentation-name');

  final span = tracer.startSpan('main');
  try {
    // do some work
    span.addEvent('some work');
  } catch (e, s) {
    span
      ..setStatus(StatusCode.error, e.toString())
      ..recordException(e, stackTrace: s);
    rethrow;
  } finally {
    span.end();
  }
}

Propagate Context

Intra-process

In order to parent spans, context must be propagated. Propagation can be achieved by manually passing an instance of Context or by using Dart Zones.

See the attach detach context examplefor more information.

Inter-process

In order to parent spans between processes, context can be serialized and deserialized using a TextMapPropagator, TextMapSetter, and TextMapGetter.

See the W3C context propagation example for more information.

High Resolution Timestamps

A tracer provider can register a web-specific time provider that uses the browser's performance API instead of DateTime when recording timestamps for a span's start timestamp, end timestamp, and span events.

import 'package:opentelemetry/web_sdk.dart' as web_sdk;

final tracerProvider =
    web_sdk.WebTracerProvider(timeProvider: web_sdk.WebTimeProvider());

Important Note: Span timestamps may be inaccurate if the executing system is suspended for sleep. See https://github.com/open-telemetry/opentelemetry-js/issues/852 for more information.

Contributing

In order to generate protobuf definitions, you must have protoc installed and available in your path.

Publishing New Versions

Only Workiva maintainers can publish new versions of opentelemetry-dart. See Publishing opentelemetry-dart