How to do simultaneous request calls using Postman collections

Newman is a command line collection runner for Postman. It allows you to run and test a Postman Collection directly from the command line. It is built with extensibility in mind so that you can easily integrate it with your continuous integration servers and build systems.

With Newman and Async, you can do simultaneous request calls which will be very helpful for performance tests.

Here are what you'll need to do to get it working:

1. Install Newman by following the instructions on http://blog.getpostman.com/2015/04/09/installing-newman-on-windows/
   In my case, I didn’t have to install Python to get it working.
2. Create/use a folder for the tests
3. Export a Postman collection into a file
   
4. Export a Postman environment that you want to invoke the calls to
   
5. Open a command prompt in administrator mode on the folder from step 2
6. Install async module by typing npm install --save async
7. Create a .js file

var path = require('path'),
  async = require('async'), //https://www.npmjs.com/package/async
  newman = require('newman'),

  parametersForTestRun = {
    collection: path.join(__dirname, 'postman_collection.json'), // your collection
    environment: path.join(__dirname, 'postman_environment.json'), //your env
  };

parallelCollectionRun = function(done) {
  newman.run(parametersForTestRun, done);
};

// Runs the Postman sample collection thrice, in parallel.
async.parallel([
    parallelCollectionRun,
    parallelCollectionRun,
    parallelCollectionRun
  ],
  function(err, results) {
    err && console.error(err);

    results.forEach(function(result) {
      var failures = result.run.failures;
      console.info(failures.length ? JSON.stringify(failures.failures, null, 2) :
        `${result.collection.name} ran successfully.`);
    });
  });



8. Run the .js file from step 7 from command prompt node fileName.js