Preparation for Failure Injection

Failure injection is the means by which we will simulate disruptive real-world events that affect production environments. Such events are used in chaos engineering to validate and understand the resiliency of your workload. Chaos engineering is a recommended practice of the AWS Well-Architected Reliability Pillar . Here you will initiate various failure scenarios and assess how your workload reacts.

Before testing, please prepare the following:

3.1 Region must be Ohio

  • We will be using the AWS Console to assess the impact of our testing
  • Throughout this lab, make sure you are in the Ohio region

SelectOhio

3.2 Get VPC ID

  • A VPC (Amazon Virtual Private Cloud) is a logically isolated section of the AWS Cloud where you have deployed the resources for your service
  • For these tests you will need to know the VPC ID of the VPC you created as part of deploying the service
  1. Navigate to the VPC management console: https://console.aws.amazon.com/vpc

  2. In the left pane, click Your VPCs

    • 1 - Tick the checkbox next to ResiliencyVPC
    • 2 - Copy the VPC ID

    GetVpcId

  3. Save the VPC ID - you will use later whenever <vpc-id> is indicated in a command

3.3 View the website used for the test application for this lab

  1. Go to the AWS CloudFormation console at https://console.aws.amazon.com/cloudformation.

    • click on the WebServersforResiliencyTesting stack
    • click on the “Outputs” tab
    • For the Key WebSiteURL copy the value. This is the URL of your test web service. CFNComplete
  2. Click the URL and it will bring up the website:
    DemoWebsite

    (image will vary depending on what you supplied for websiteimage)

  3. Get familiar with the service website

    1. Note the availability_zone and instance_id
    2. Refresh this website several times watching these values
    3. Note the values change. You have deployed one web server per each of three Availability Zones.
      • The AWS Elastic Load Balancer (ELB) sends your request to any of these three healthy instances.
      • Refer to the diagram at the start of Step 1 to review your deployed system architecture.
    Availability Zones (AZs) are isolated sets of resources within a region, each with redundant power, networking, and connectivity, housed in separate facilities. Each Availability Zone is isolated, but the Availability Zones in a Region are connected through low-latency links. AWS provides you with the flexibility to place instances and store data across multiple Availability Zones within each AWS Region for high resiliency.
    Learn more: After the lab learn more about Regions and Availability Zones here