Introduction to load balancers
In this second section, we will discuss the basics between utilizing layer 7 and layer 4 load balancers. To understand the differences between the types of load balancers, it's important to understand the Open Systems Interconnection (OSI) model. Understanding the different layers of the OSI model will help you to understand how different solutions handle incoming requests.
Understanding the OSI model
When you hear about different solutions to expose an application in Kubernetes, you will often hear a reference to layer 7 or layer 4 load balancing. These designations refer to where each operates in the OSI model. Each layer offers different functionality; a component that runs at layer 7 offers different functionality to a component in layer 4.
To begin, let's look at a brief overview of the seven layers and a description of each. For this chapter, we are interested in the two highlighted sections, layer 4 and layer 7:
