Performance Testing an Api using Artillery and Faker

I needed to do some performance testing on a lambda, behind an api gateway to just prove that it scaled well, and my initial thought was to turn to something I’ve used before, such as Gatling, JMeter or Siege. I decided to try out artillery.io, and was very impressed!!


According to their site:

Artillery is a modern, powerful & easy-to-use load testing toolkit. Use it to ship scalable applications that stay performant & resilient under high load

Its a library, in node, which is extremely easy to setup and use. The documentation isn’t the best in terms of examples, but I managed to soldier on.

What I was testing was an api, which I needed to post a block of json. Since I wanted the payload to be dynamic (each payload needed to have a different email address), I used Faker, which is another node library which will generate random, but realistic style data for a variety of data fields such as emails, phone numbers, addresses, dates, colours images etc. It seems to be able to do pretty much anything!


First you need to install faker and artillery from npm

npm i artillery faker

Then you will need to create your artillery config file. Here is the one I used:

  • fullapplication-test.yml

  target: "https://url-changed.com"
  processor: "./random-fullapplication-payload.js"
    - duration: 120
      arrivalRate: 5
  - name: "FullApplication Requests"
      - function: "generateRandomPayload"
      - post:
          url: "/fullapplication"
          json: "{{payload}}"        

This sends, for 2 minutes, 5 requests per second to https://url-changed.com/fullapplication using a post and the payload that I generate in the function “generateRandomPayload”.

  • random-fullapplication-payload.js
'use strict';
var Faker = require('faker');
module.exports = {

function generateRandomPayload(userContext, events, done) {    
  var payload = {

  payload.Email =  Faker.internet.exampleEmail();  
  userContext.vars.payload = payload;  
  return done();

When the function is called, the payload is generated based on my template, and I swap out the email, based on the value generated from Faker.

Runnning and reporting

To run the test, and generate the report i ran the following command

artillery run -o report.json fullapplication-test.yaml
artillery report report.json

The html outputted report contains a really good breakdown of how the test performed. I was pretty impressed to get so much out of it, for only an hour or so’s work!!

Summary report @ 12:13:28(+0100) 2018-06-21
 Scenarios launched:  600
 Scenarios completed: 600
 Requests completed:  600
 RPS sent: 4.42
 Request latency:
   min: 1269.7
   max: 29066
   median: 4183
   p95: 15118.6
   p99: 17637.6
 Scenario counts:
   FullApplication Requests: 600 (100%)
   201: 550
   500: 49
   504: 1

Written on June 21, 2018.