Instrumentile GL

Instrumentile GL is a plugin for Mapbox GL JS for tracking page render time for embed pages. It updates the original Instrumentile project by @camilleanne for Mapbox GL JS.

Tracking these metrics is important in order for Mapbox to understand the performance of tile loading for users, in addition to the performance of different Content Delivery Networks (CDN), such as Amazon and Akamai. We also collect these metrics in order to watch for network neutrality violations from different ISPs.

The implementation relies upon the performance.timing API, which is fully available in Mapbox GL JS >=0.44.0 via the collectResourceTiming option. Data is collected from front-end embeds and pushed through mapbox-events to api-events.

Firefox Compatibility

As of this writing, the current version of Firefox Quantum (58) suffers from a bug affecting the accessibility of the performance.timing API in web workers. This is slated to be fixed in Firefox 60. In the meantime, relevant parts of Mapbox GL JS and Instrumentile GL will fail silently.

Installation

npm install @mapbox/instrumentile-gl

Usage

const mapboxgl = require('mapbox-gl');
const instrumentile = require('@mapbox/instrumentile-gl');

mapboxgl.accessToken = VALID_ACCESS_TOKEN;

// optional check for web worker performance API support -- avoids errors on Mapbox GL 0.44 & 0.45
instrumentile.supportsWebWorkerPerformanceCollection(function(err, supported) {
    const map = new mapboxgl.Map({
        container: 'map',
        style: 'mapbox://styles/mapbox/streets-v9',
        collectResourceTiming: supported
    });

    const inst = new instrumentile(map, {
        token: VALID_ACCESS_TOKEN,
        api: 'https://api.tiles.mapbox.com', // this is the default
        source: 'whatevs' // optional source string that is sent along every event
    });
});

Tests

Unit tests can be run with npm test and use mapbox-gl-js-mock. The somewhat tautologous nature of these unit tests means that browser-based integration testing is essential.

To run these integration tests, run npm run test-browser and open your browser to http://localhost:3000/. Map load, GeoJSON and Vector Tile events should fire in the course of the map loading. You will need to click and pan the map to fire their corresponding events.

Deploying

Ensure you are authed and run bin/deploy.sh.