var http = require('http');
http.createServer(function (req, res) {
 res.writeHead(200, {'Content-Type': 'text/plain'});
 res.end('Hello World\n');
}).listen(8080, 'localhost');
console.log('Server running at http://localhost:8080');

When to use Node.js?

You should have heard of this proverb:

"If all you have is a hammer, everything looks like a nail!"

This makes a lot of sense in this context. Node.js is not a technology to depend on all the application problems that you intend to solve and if not chosen wisely, the decision will backfire. Node.js is well suited for applications that are expected to handle a huge amount of concurrent connections. Also, it should be noted that it is most suited for applications where each incoming request requires very few CPU cycles. This means that if you intend to do computation-intensive tasks on requests, it will end up blocking the event loop—thereby impacting other requests concurrently processed by the web server. Node.js is well suited for real-time web applications, such as chat rooms, collaboration tools, online games, and so on. So when deciding whether to use or not use Node.js, we should analyze the application context seriously and figure out whether Node.js really suits the context of the application.

As we have briefly gone through the features and concept of Node.js, now let's look into the NoSQL and MongoDB side.