Azure Core tracing library for JavaScript

This is the core tracing library that provides low-level interfaces and helper methods for tracing in Azure SDK JavaScript libraries which work in the browser and Node.js.

Getting started

Installation

Install this library using npm as follows

npm install @azure/core-tracing

Key Concepts

The @azure/core-tracing package supports enabling tracing for Azure SDK packages, using an OpenTelemetry Tracer. If you are using OpenCensus instead, we provide an OpenCensusTracerWrapper that allows you to convert an OpenCensus Tracer into an OpenTelemetry Tracer.

By default, all libraries log with a NoOpTracer that takes no action. To change this, you have to use setTracer to set a new default Tracer.

Examples

Example 1 - Setting an OpenTelemetry Tracer

const opentelemetry = require("@opentelemetry/core");
const { BasicTracer, SimpleSpanProcessor } = require("@opentelemetry/tracing");
const { ZipkinExporter } = require("@opentelemetry/exporter-zipkin");
const { setTracer } = require("@azure/core-tracing");

const exporter = new ZipkinExporter({
  serviceName: "azure-tracing-sample"
});
const tracer = new BasicTracer();
tracer.addSpanProcessor(new SimpleSpanProcessor(exporter));

opentelemetry.initGlobalTracer(tracer);

const rootSpan = opentelemetry.getTracer().startSpan("root");

// Call some client library methods and pass rootSpan via tracingOptions.

rootSpan.end();
exporter.shutdown();

Example 2 - Setting an OpenCensus Tracer

const tracing = require("@opencensus/nodejs");
const { ZipkinTraceExporter } = require("@opencensus/exporter-zipkin");
const {
  setTracer,
  OpenCensusTracerWrapper,
  OpenCensusSpanWrapper
} = require("@azure/core-tracing");

const tracer = tracing.start({ samplingRate: 1 }).tracer;

tracer.registerSpanEventListener(
  new ZipkinTraceExporter({
    serviceName: "azure-tracing-sample",
    bufferTimeout: 2
  })
);
setTracer(new OpenCensusTracerWrapper(tracer));
tracer.startRootSpan({ name: "root" }, async (rootSpanEx) => {
  const rootSpan = new OpenCensusSpanWrapper(rootSpanEx);
  // Call some client library methods and pass rootSpan via tracingOptions.
  rootSpanEx.end(); // rootSpan.end() should work as well
});

Example 3 - Passing parent Spans to library operations

// Given a BlobClient from @azure/storage-blob
const result = await blobClient.download(undefined, undefined, {
  tracingOptions: {
    spanOptions: { parent: rootSpan }
  }
});

Contributing

If you'd like to contribute to this library, please read the contributing guide to learn more about how to build and test the code.