React-tracing NPM

📈 React Tracing

Goal

react-tracing enables React and React Native developers to build faster products by making the real-world performance visible. Although it is optimized for React and React Native we also support pure JS.

For this we want to use well-known tooling from the backend world and bring it to the frontend, so that engineering teams might gain a better understanding where a loading time improvement might help the most.

Imagine having graphs like this showing real users using your (web-)app when you want to decide which performance issue to tackle next:

Introduction

Terminology

This section aims to give you a small overview into the language used in opentracing

Term	Description
span	a single operation that is traced
child span	like functions calls are nested, spans can be, too

How we manage your spans

In other tracing solutions you have to define which span is the child of which, but react-tracing handles this for you. Therefore react-tracing uses a stack, making use of Javascripts Single-Threadedness, to determine which spans should rely on each other. This stack is stored in the global scope (it's a bit ugly, do you have a better idea?) under window.reactTracing.stack or global.reactTracing.stack.

Supported Tracing Implementations

We can use every opentracing solution in general, but currently there is only one, therefore it is not configurable yet. As soon as there are other solutions we will add them here.

zipkin-javascript-opentracing

Working with multiple systems

Every time you send a fetch or xhr request with react-tracing's instrumented versions of them the X-B3-TraceId, X-B3-SpanId HTTP headers are set, so that your server can pick the span up and extend the tracing context.

Environment Setup

You need a Zipkin instance running on an accessible server. For development puropses you can start one with docker: docker run -d -p 9411:9411 openzipkin/zipkin

Usage

import Tracing from "react-tracing";
const tracer = new Tracing({
    serviceName: "Frontend",
    endpoint: "http://localhost:9111",
    kind: "client", // default
});

// TRACKING HTTP REQUESTS
// ======================

// You have two options here depending on your style of usage
// a) You can either use it locally, enabling you to set a different service name per fetch
const defaultFetch = tracer.fetch();
const tracingXhr = tracer.xhr({ XMLHttpRequest }); // last param optional, otherwise a global is used

// b) You can choose to let us handle everything for you
// This mutates the global fetch and XHR request
tracer.initGlobalNetworkTracer();

// You can define a span that generates you the span names, this is the default one.
// If you want to use the default and a third param pass anything that is not a function as the second parameter.
const getSpanName = ({ url, method, body }) => `${url}-${method}`;
const tracedFetch = tracer.fetch({ getSpanName, fetch});



// TRACKING USER ACTIONS
// =====================

// You can use it in React
const Link = tracer.component("a")

// You can use it in React Native
const Touchable = tracer.component(TouchableHighlight);

// Every onPress / onClick / onLongPress is wrapped with a function like this
// If a promise is returned, the span will end once it resolves or rejects
const clickHandler = function() {
    return fetch("http://foo.de").then(...);
};
const tracedClickHandler = tracer.wrap(clickHandler);

// Usage in the component
const MyTracedComponent = () => (
  <Touchable
    tracingName="create-new-order"
    // Either use static additional infos
    tracingInfo={{
      buttonLabel: 'ClickMe',
      userId: 42,
    }}
    // Or use dynamic ones
    tracingInfo={e => ({
      clickPosition: e.targetX,
    })}
    {...usualProps}
  >
    <Text>ClickMe</Text>
  </Touchable>
);



// ADD YOUR OWN TRACING
// ====================

function myVeryLongFunction() {
  tracing.startSpan("Long Function");
  asyncFunction().then(() => {
     tracing.startSpan("Synchronous Bitcoin Mining");
     try {
      mineBitcoinsAndDonateThem();
     } catch(e) {
       // Something went wrong, let's log the error
       tracing.log({
         miningError: e
       });
     }
     tracing.finishSpan();
  }).finally(() => {
    tracing.finishSpan();
  });
}