Load testing script Atlas

loadTest.js

const MongoClient = require("mongodb").MongoClient;
const { LoremIpsum } = require("lorem-ipsum");
const cluster = require('cluster');

const MONGOURI = "MONGO_URI";
const DB = "test_db";
const COLL = "test_coll";


/* Lorem Ipsum Generator */
/* USAGE - lorem.generateWords */
const lorem = new LoremIpsum({
  sentencesPerParagraph: {
      max: 8,
      min: 4
  },
  wordsPerSentence: {
      max: 16,
      min: 4
  }
});

function generateSampleDocument(batchSize, docLength) {
  const types = ["string", "date"];
  const wBatch = [];
    const doc = {
      field1: lorem.generateWords(),
      field2: lorem.generateWords(),
      field3: lorem.generateWords(),
      field4: lorem.generateWords(),
      cdt: new Date(),
      udt: new Date()
    }

  return doc;
}


async function main(pid) {
  // setup client
  const client = new MongoClient(MONGOURI, { minPoolSize: 2999, maxPoolSize: 3000, useNewUrlParser: true });
  // Connect to the mongodb client
  await client.connect().catch(console.error);

  console.log("Connection Created", new Date().getTime())

  // Setup collection
  const collection = client.db(DB).collection(COLL);

  collection.insertOne(generateSampleDocument()).then(() => {
    console.log("Sample Inserted");
  })

  // run the load
  for (let counter = 0; counter < 100000; counter++) {
    collection.insertOne(generateSampleDocument()).then(_ => {});
  }

  console.log("Function Completed = " + pid + " = " + new Date().getTime());
}

if (cluster.isMaster) {
  console.log(`Master ${process.pid} is running`);

  // Fork workers.
  for (let i = 0; i < 2; i++) {
    cluster.fork();
  }

  cluster.on('exit', (worker, code, signal) => {
    console.log(`worker ${worker.process.pid} died`);
  });
} else {
  // Workers can share any TCP connection
  // In this case it is an HTTP server
  main(process.pid).catch(e => {
    console.error(e);
  })

  console.log(`Worker ${process.pid} started`);
}



// const client = new MongoClient(MONGOURI, { useNewUrlParser: true, useUnifiedTopology: true });
// client.connect(err => {
//   if (err) {
//     console.error(err);
//     return;
//   }

//   /* Client Collection */
//   const coll = client.db(DB).collection(COLL);


//   /* Generate Sample Document */

//   for (let i = 0; i < 10000000; i++) {
//     coll.insertOne(generateSampleDocument());  
//   }
// });

package.json

{
  "name": "poc-tool-node",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.17.1",
    "lorem-ipsum": "^2.0.3",
    "mongodb": "^3.6.1"
  }
}