Introduction: Scale the Application

In this chapter, we’ll scale the app up and down. The methods we’ll learn are manual and require a human to implement them. In the real world, we’ll use a Horizontal Pod Autoscaler (HPA) to make scaling automatic. These are beyond the scope of this course, but the things we’ll learn here will be extremely valuable.

However, Kubernetes also has objects that enable automatic scaling, but they’re beyond the scope of a quick start course.

We’ve split the chapter as follows.

• Prerequisites

• Scale an application up

• Scale an application down

• The role of labels

• Declarative vs. imperative

Prerequisites

If you’ve been following along, you’ll already have a single Deployment managing replicas of the app we containerized in a previous chapter. If you already have this Deployment running, you can skip to the next lesson.

You’ll know that we have five replicas of the application already.