main.js

const express = require('express');
const app = express();
const { Worker } = require('worker_threads')

app.get('/', (req, res) => {
  res.send('Hello Express app!')
});

app.listen(7860, () => {
  console.log('server started');
});

function runService(workerData) {
  return new Promise((resolve, reject) => {
    const worker = new Worker('./index.js', { workerData });
    worker.on('message', resolve);
    worker.on('error', reject);
    worker.on('exit', (code) => {
      if (code !== 0)
        reject(new Error(`Worker stopped with exit code ${code}`));
    })
  })
}

for(var i = 0;i < 8;i++){
  runService(1)
}