AWS Certified DevOps Engineer - Professional Exam: Answer Explanation

Dynamic Deployment and Blue/Green Deployment

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Question

Your team has developed an online food order system, which is deployed in AWS.

You created two ASGs to attach to an ELB.

ASG1 is live and ASG2 is idle (desired number is 0)

When a new release is published, the new version is deployed in the ASG2 and fully tested.

If no issue is found, ASG2 becomes alive and ASG1 becomes idle (down-scaled to zero servers)

Which kind of deployment/delivery strategy can it be called? (Select TWO.)

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D. E.

Correct Answer - A, C.

The SDLC Automation domain of AWS Certified DevOps Engineer - Professional (DOP-C01) Exam Guide has covered how to determine the deployment/delivery strategies (e.g., A/B, Blue/green, Canary, Red/Black) and how to implement them using AWS Services.

The exam guide can be found in https://d1.awsstatic.com/training-and-certification/docs-devops-pro/AWS%20Certified%20DevOps%20Engineer%20Professional_Exam%20Guide_v1.5_FINAL%20(2).pdf.

Option A is CORRECT: Because Blue/Green deployment contains two identical environments and the system can switch to the new environment for all the traffic.

In this case, it has used two ASGs to handle the Blue/Green deployment.

Option B is incorrect: Because for rolling deployments, the system divides the whole environment into batches and deploys one batch at a time for the new software until the whole system is done.

However, in this case, it swaps to the new release for all the traffic if the new code has no issue after being tested.

Option C is CORRECT: Because both red/black and blue/green deployment represent the same concept.

In this case, the Red version (ASG1) is live in production.

When the Black version (ASG2) is fully operational, the system has directed all traffic to it.

Option D is incorrect: Because A/B testing is a method where two versions of an application or a feature get tested with the same users, and the best is picked to win.

It is not the same case as this scenario.

Option E is incorrect: Because for Canary deployment, a subset of real users/traffic is routed to the new version.

After the test metrics pass your requirements, the new release starts to server all the traffic.

This case does not belong to Canary deployment.

The described deployment/delivery strategy can be classified as a combination of two approaches:

  1. Blue/Green Deployment

  2. Rolling Deployment

  3. Blue/Green Deployment: Blue/Green Deployment is a technique that allows for zero-downtime deployments. This approach involves creating two identical environments, one of which is currently live (blue), while the other is idle (green). The new version of the application is deployed to the idle environment (green) and fully tested. Once the new version passes all the tests, traffic is redirected from the old environment (blue) to the new environment (green). The old environment is then decommissioned. This approach ensures that the new version of the application is deployed without any downtime or impact on the end-users.

In the context of the given scenario, ASG1 and ASG2 are analogous to the blue and green environments of a typical Blue/Green deployment. When the new version of the application is released, it is deployed to the ASG2, which is currently idle. Once the new version of the application passes all the tests, traffic is redirected from ASG1 to ASG2. This approach ensures zero-downtime deployment.

  1. Rolling Deployment: Rolling Deployment is a technique that involves deploying a new version of the application in small increments, typically one server at a time. This approach ensures that there is no sudden surge in traffic, and the new version can be thoroughly tested before rolling out to the entire fleet.

In the context of the given scenario, Rolling Deployment is used when the new version of the application is deployed to ASG2, which is currently idle. Once the new version passes all the tests, the fleet is scaled up incrementally, one server at a time. Once ASG2 is fully scaled up, ASG1 is scaled down, and traffic is redirected to ASG2.

Therefore, the deployment/delivery strategy used in the given scenario can be classified as Blue/Green Deployment and Rolling Deployment.