easygraphql-load-tester is a node library created to make load testing on GraphQL based on the schema; it'll create a bunch of queries, that are going to be the ones used to test your server.

Installation

To install the package on your project just run on the root of your project

$ npm install easygraphql-load-tester --saved-dev

$ yarn add easygraphql-load-tester -D

easygraphql-load-tester

Supported packages

1. Using .artillery() with a artillery setup.
2. Using .k6() with a k6 setup.
3. Using .createQuery() that'll create the queries, so you can use with your favorite load tester.

How to use it?

• Import easygraphql-load-tester package.
• Read the schema.
• Initialize the tester, and pass the schema as the first argument.
  • If there are multiples schemas pass an array with the schemas an argument.
  • Note: In order to use multiples schema files, the queries and mutations must be extended. +
• The second argument is the arguments on the queries, only if there are some of them.

One schema file

'use strict'

const LoadTesting = require('easygraphql-load-tester')
const fs = require('fs')
const path = require('path')

const userSchema = fs.readFileSync(
  path.join(__dirname, 'schema', 'user.gql'),
  'utf8'
)

const loadTester = new LoadTesting(userSchema)

Multiples schemas files

'use strict'

const LoadTesting = require('easygraphql-load-tester')
const fs = require('fs')
const path = require('path')

const userSchema = fs.readFileSync(
  path.join(__dirname, 'schema', 'user.gql'),
  'utf8'
)
const familySchema = fs.readFileSync(
  path.join(__dirname, 'schema', 'family.gql'),
  'utf8'
)

const loadTester = new LoadTesting([userSchema, familySchema])

Using GraphQL.js

'use strict'

const { GraphQLSchema, GraphQLObjectType, GraphQLString } = require('graphql')
const LoadTesting = require('easygraphql-load-tester')

const schema = new GraphQLSchema({
  query: new GraphQLObjectType({
    name: 'RootQueryType',
    fields: {
      hello: {
        type: GraphQLString,
        resolve() {
          return 'world'
        },
      },
    },
  }),
})

const loadTester = new LoadTesting(schema)

Artillery

To use with artillery, you must have it installed in your project, in case you don't have it just run:

$ npm install artillery --saved-dev

index.js

You should configure your index.js file:

'use strict'

const fs = require('fs')
const path = require('path')
const LoadTesting = require('../../lib')

const familySchema = fs.readFileSync(path.join(__dirname, 'schema.gql'), 'utf8')

const args = {
  getFamilyInfoByIsLocal: {
    isLocal: true,
    test: ['a', 'b'],
    age: 10,
    name: 'test',
  },
  searchUser: {
    name: 'demo',
  },
  createUser: {
    name: 'demo',
  },
  createCity: {
    input: {
      name: 'demo',
      country: 'Demo',
    },
  },
}

const easyGraphQLLoadTester = new LoadTesting(familySchema, args)

const customQueries = [
  `
    query SEARCH_USER($name: String!) {
      searchUser(name: $name) {
        name
      }
    }
  `,
]

const testCases = easyGraphQLLoadTester.artillery({
  customQueries,
  onlyCustomQueries: true,
  queryFile: true,
  withMutations: true,
})

module.exports = {
  testCases,
}

Artillery options

type ArtilleryOptions = {
  customQueries?: string[]
  onlyCustomQueries?: boolean
  selectedQueries?: string[]
  queryFile?: boolean
  queryFilePath?: string
  withMutations?: boolean
}

This is optional, you can leave the second argument empty, if you don't want to pass any options

Custom queries

You can pass custom queries to test on your load test. To create them, create an array of strings (queries). You can use variables, and it's going to use the variables defined on the arguments used to initialize LoadTesting or, you can pass the value of the argument searchUser(name: "demo") {...}

const customQueries = [
  `
    query SEARCH_USER($name: String!) {
      searchUser(name: $name) {
        name
      }
    }
  `,
]

Only custom queries

If this is set to true it's going to use the custom queries passed.

Selected queries

You can select a list of the queries you want to test, to do this, you must create an array of strings with the name of the queries to test; this is optional, if you don't create it, all the queries are going to be tested.

const selectedQueries = ['getFamilyInfo', 'searchUser']

Query file

You can select, if you want to save a json file with all the queries that where tested, to do it, on the options pass queryFile: true, if you don't pass anything it is not going to be saved.

Query file path

You can select the path that you want to use to save the query file, if it's not set it'll use by default path.resolve()

Mutations

You can use easygraphql-load-tester to test your mutations as well; to do it, on the options pass withMutations: true, if you don't pass anything it is only going to test the queries. If you set withMutations: true, don't forget to add the input values on the args

artillery.yml

The artillery file should have this minimum configuration, you can add yours in case it is needed:

config:
  target: 'http://localhost:5000/'
  phases:
    - duration: 5
      arrivalRate: 1
  processor: './index.js'
scenarios:
  - name: 'GraphQL Query load test'
    flow:
      - function: 'testCases'
      - loop:
          - post:
              url: '/'
              json:
                query: '{{ $loopElement.query }}'
                variables: '{{ $loopElement.variables }}'
          - log: '----------------------------------'
          - log: 'Sent a request to the {{ $loopElement.operation }}: {{ $loopElement.name }}'
          - log: 'And variables {{ $loopElement.variables }}'
        over: cases

In this case the server is running on http://localhost:5000/

How to run it

To run your load test, add this script on your package.json:

"scripts": {
  "easygraphql-load-tester": "artillery run artillery.yml"
}

and then run on the terminal

$ npm run easygraphql-load-tester

In this case the artillery file is called artillery, but you can name yours with your favorite name and run artillery run <MY_FILE_NAME>.yml

Result

The result is going to be something like this if you apply the basic configuration

 All virtual users finished
 Summary report @ 15:03:05(-0500) 2018-11-17
   Scenarios launched:  5
   Scenarios completed: 5
   Requests completed:  40
   RPS sent: 8.95
   Request latency:
     min: 1.2
     max: 13
     median: 2
     p95: 6
     p99: 13
   Scenario counts:
     GraphQL Query load test: 5 (100%)
   Codes:
     200: 40

k6

To use with k6, you must have it installed on your computer, in case you don't have it, visit the installation guide

index.js

You should configure your index.js file:

'use strict'

const fs = require('fs')
const path = require('path')
const LoadTesting = require('../../lib')

const familySchema = fs.readFileSync(path.join(__dirname, 'schema.gql'), 'utf8')

const args = {
  getFamilyInfoByIsLocal: {
    isLocal: true,
    test: ['a', 'b'],
    age: 10,
    name: 'test',
  },
  searchUser: {
    name: 'demo',
  },
}

const easyGraphQLLoadTester = new LoadTesting(familySchema, args)

const queries = [
  `
    query SEARCH_USER($name: String!) {
      searchUser(name: $name) {
        name
      }
    }
  `,
]

easyGraphQLLoadTester.k6('k6.js', {
  customQueries: queries,
  selectedQueries: ['getFamilyInfo', 'searchUser'],
  vus: 10,
  duration: '10s',
  queryFile: true,
  out: ['json=my_test_result.json'],
})

The first argument is the name of the k6 configuration file

K6 options

type K6Options = {
  customQueries?: string[]
  onlyCustomQueries?: boolean
  selectedQueries?: string[]
  queryFile?: boolean
  queryFilePath?: string
  withMutations?: boolean
  vus?: number
  duration?: string
  iterations?: number
  out?: string[]
}

This is optional, you can leave the second argument empty, if you don't want to pass any options

Custom queries

You can pass custom queries to test on your load test. To create them, create an array of strings (queries). You can use variables, and it's going to use the variables defined on the arguments used to initialize LoadTesting or, you can pass the value of the argument searchUser(name: "demo") {...}

const customQueries = [
  `
    query SEARCH_USER($name: String!) {
      searchUser(name: $name) {
        name
      }
    }
  `,
]

Only custom queries

If this is set to true it's going to use the custom queries passed.

Selected queries

You can select a list of the queries you want to test, to do this, you must create an array of strings with the name of the queries to test; this is optional, if you don't create it, all the queries are going to be tested.

const selectedQueries = ['getFamilyInfo', 'searchUser']

Query file

You can select, if you want to save a json file with all the queries that where tested, to do it, on the options pass queryFile: true, if you don't pass anything it is not going to be saved.

Mutations

You can use easygraphql-load-tester to test your mutations as well; to do it, on the options pass withMutations: true, if you don't pass anything it is only going to test the queries. If you set withMutations: true, don't forget to add the input values on the args

Virtual users

You can select how many virtual users do you want for your tests, just pass to the options vus: <NUMBER_OF_VUS>.

Duration

You can select the duration for your tests, just pass to the options duration: '<DURATION>s'. It should be a string with units of the time e.g. s

Iterations

You can select the number of iterations to run by passing iterations: <ITERATIONS>. It should be an integer.

Out

You can also make k6 output detailed statistics in JSON format by using the --out/-o option for k6 run. More info

k6.js

The k6 file should have this minimum configuration, you can add yours in case it is needed:

Note: dont' change the name and the route of the queries ./easygraphql-load-tester-queries.json

import http from 'k6/http'

const queries = JSON.parse(open('./easygraphql-load-tester-queries.json'))

export default function() {
  for (const query of queries) {
    const url = 'http://localhost:5000/'
    const payload = JSON.stringify({
      query: query.query,
      variables: query.variables,
    })
    const params = { headers: { 'Content-Type': 'application/json' } }
    http.post(url, payload, params)
  }
}

In this case the server is running on http://localhost:5000/

How to run it

To run your load test, add this script on your package.json:

"scripts": {
  "easygraphql-load-tester": "node index.js"
}

and then run on the terminal

$ npm run easygraphql-load-tester

How to use it with your actual queries

1. Install in your project merge-graphql-schemas
2. Import all your queries:

   const queries = fileLoader(path.join(__dirname, '..', '**/*.graphql'))

3. Pass them as customQueries in the options, with onlyCustomQueries: true as well.
4. Set in the args the values to used on the variables of the queries/mutations.

Success cases

If you want to share your success case using easygraphql-load-tester feel free to create a PR so the community can learn from your story.

Importance of using dataloaders

Some time ago I was working on a GraphQL project that includes activities and each activity can have some comments with the info of the user that created the comment. The first thing that you might think is that it is a problem of query n + 1 , and yes; it is!

I decided to implement dataloaders but for some reason, there was an error on the implementation, so it wasn't caching the query and the result was a lot of request to the database. After finding that issue I implemented it on the right way reducing the queries to the database from 46 to 6.

Results without dataloaders

All virtual users finished
Summary report @ 10:07:55(-0500) 2018-11-23
  Scenarios launched:  5
  Scenarios completed: 5
  Requests completed:  295
  RPS sent: 36.88
  Request latency:
    min: 1.6
    max: 470.9
    median: 32.9
    p95: 233.2
    p99: 410.8
  Scenario counts:
    GraphQL Query load test: 5 (100%)
  Codes:
    200: 295

Results with dataloaders

All virtual users finished
Summary report @ 10:09:09(-0500) 2018-11-23
  Scenarios launched:  5
  Scenarios completed: 5
  Requests completed:  295
  RPS sent: 65.85
  Request latency:
    min: 1.5
    max: 71.9
    median: 3.3
    p95: 19.4
    p99: 36.2
  Scenario counts:
    GraphQL Query load test: 5 (100%)
  Codes:
    200: 295

Examples

You can check the example

License

The MIT License

Copyright (c) 2018 EasyGraphQL

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.