The preference for scaling out

Scaling out is a better scaling solution compared to scaling up. Scaling up or down means resizing VM instances. When a VM is resized, it generally needs to be restarted, which has its own disadvantages. First, there is downtime for the machine. Second, if there are active users connected to the application on that instance, they might face the unavailability of the application, or they might even have lost transactions. Scaling out does not impact existing VMs. It provisions newer machines and adds them to the group.