Introduction to load balancers
Before discussing different 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 here 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 than 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:
Table 6.3 OSI model layers
You don't need to be an expert in the OSI layers, but you should understand...
