gql-profiler

GraphQL Profiler

A standalone performance profiler for GraphQL resolvers

Getting Started

Installation

Add the profiler to your project dependencies.

npm install --save gql-profiler
yarn add gql-profiler

Choose a reporter, wrap your resolvers with the profiler and use the reporter whenever you want:

import express from 'express';
import { makeExecutableSchema } from 'graphql-tools';
import bodyParser from 'body-parser';
import { graphqlExpress, graphiqlExpress } 'apollo-server-express';
import { profileResolvers, htmlReporter } from 'gql-profiler';
import typeDefs from './typeDefs';
import resolvers from './resolvers';

const reporter = htmlReporter();

const schema = makeExecutableSchema({
  typeDefs,
  resolvers: profileResolvers(resolvers, { reporter }),
});

const app = express();

app.get('/profiler', (req, res) => {
    res.send(reporter.getHtml());
});

app.use('/graphql', bodyParser.json(), graphqlExpress({ schema }));

app.listen(3000, () => {
    console.log('Server listening at http://localhost:3000');
});

The profiler report will be available at http://localhost:3000/profiler

Configuration

profileResolvers(resolvers, {
    reporter, // A reporter to gather your data (see the list below) - Mandatory
    enabled: true, // If false, the resolvers aren't profiled
    disableInProduction: true, // Force disable the profiler the env is production
    env: process.env.NODE_ENV,
    getResolverName: () => '', // Function to get the resolver name
});

Available Reporters

nullReporter

import { nullReporter } from 'gql-reporter';
const reporter = nullReporter();

Does literaly nothing and doesn't have useful API.

memoryReporter

import { memoryReporter } from 'gql-reporter';
const reporter = memoryReporter();
const events = reporter.getEvents(); // Retrieve each resolver calls
const hierarchy = reporter.getHierarchy(); // Same, but in a dependency tree
reporter.reset(); // Delete all data in the reporter

htmlReporter

import { htmlReporter } from 'gql-reporter';
const reporter = htmlReporter();
const events = reporter.getEvents(); // Retrieve each resolver calls
const hierarchy = reporter.getHierarchy(); // Same, but in a dependency tree
const html = reporter.getHtml(); // Build a nice HTML page with charts
reporter.reset(); // Delete all data in the reporter

More soon?

• websocketReporter
• chromeDevtoolsReporter
• redisReporter
• traceEventFormatReporter

Write your own reporter

Write a reporter is very simple, here is an example for of a consoleReporter:

import uuid from 'uuid';

const consoleReporter = () => ({
    // Instanciate a new event that will be passed through the other functions
    newEvent: (resolver, args, name) => {
        return { id: uuid.v4(), name };
    },
    start: (evt) => {
        console.log(`${evt.name}#${evt.id} started at`, new Date());
    },
    end: (evt, result) => {
        console.log(`${evt.name}#${evt.id} ended at`, new Date());
    },
    error: (evt, error) => {
        console.log(`${evt.name}#${evt.id} encountered an error at`, new Date());
        console.error(error);
    },
});

Only the newEvent function is mandatory. But if you don't provide any of these function, the profiler will fail silently without crashing the resolver.

License

Comfygure is licensed under the MIT License, sponsored and supported by marmelab.