NodeJS Concurrency

concurrency.js

const http = require('http');
const cluster = require('cluster');

if (cluster.isMaster) {
    
    console.info('Starting...');

    console.info('Worker master started');
    
    const numCpus = require('os').cpus().length;

    for (var cpu = 0; cpu < numCpus; cpu++) {
        cluster.fork();
    }

    for (var id in cluster.workers) {
        workerEvents(cluster.workers[id]);
    }

} else {

    console.info('Starting worker ' + cluster.worker.id);

    http.createServer((request, response) => {

        const time = (Math.random() * 10) * 100;

        setTimeout(() => {
            response.end('ok');
            process.send({ datetime: new Date() });
        }, time);

    }).listen(8000);

}

function workerEvents (worker) {

    worker.on('message', (data) => {
        console.log('Worker ' + worker.id + ' response ' + data.datetime);
    });

    worker.on('exit', () => {
        console.log('Worker ' + worker.id + ' exited');

        console.info('Starting new worker');

        workerEvents(cluster.fork());
    });

}