Introduction

During the Well-Architected Framework Review you learned how important is to build a resilient solution to protect against failure. You understood the risks and business impact in case of failure.
For this task the following architecture has been pre-provisioned:

In this task, you will create two additional subnets in a second Availability Zone to improve application reliability. We can improve availability for applications by using two Availability Zones for our deployment and by decoupling the applications and dividing the tiers. We will use services that work across multiple Availability Zones, such as Elastic Load Balancing, Auto Scaling and Amazon RDS Multi-AZ. This will ensure tolerance to failures on the resource level and on the Availability Zone level.

At the end of this task this will be the lab architecture: