NodeJS Scaling - Scaling the x-axis

To scale along the x-axis means to clone your app. This means running the exact same application in another instance, and then handling the traffic between the two instances instead of one. For example, let's say you have a business or a server that provides advice to clients. As word gets out about your business, you'll be providing a lot of advice. This could lead to long lines and long wait times among your clients. 

How are you going to deal with all this traffic? 

Well, one option is to clone your booth. That is to open more advice booths, and split the traffic between them. Each booth provides the exact same service, and they each operate independently on a part of the traffic. We just scaled our advice booth across the x-axis. We can scale our node application, even the monolith, by running separate instances of the same application and then splitting the traffic between those instances. 

We can scale further along the x-axis by running multiple instances of our application on multiple machines. Today, it's rather easy to scale our application by running multiple instances across multiple data centers positioned worldwide. If a particular area or region gets more traffic, you simply clone more instances in that region.