Exercise 8.1 – Extending your VPC to host database subnets

In Chapter 7, AWS Compute Services, you expanded your VPC to include both private subnets and public subnets. Generally, you would only host services in a public subnet that would need direct exposure on the internet. Examples include the bastion host server we deployed earlier in Chapter 7, AWS Compute Services (which we will discuss in the next chapter).

Most applications are deployed across tiers – so, for example, you can have a web tier, an application tier, and a database tier. These different tiers are designed to separate different components of your application stack, allowing you to create a degree of isolation, as well as benefit from a layered security model. In Chapter 7, AWS Compute Services , as part of Exercise 7.1 – Expanding ProductionVPC so that it includes two public subnets and two private subnets, you also configured two private subnets across two Availability Zones to host your...