Exam AWS Certified Developer Associate topic 1 question 27 discussion

A is the answer Immutable infrastructure has become a new norm in IT operations. Immutable Deployment is one of those approaches, and it simply means: Immutable: the “staging” environment, once ready to become production, doesn't change. If we need to change something, we then deploy new code on completely new infrastructure. The benefits of an immutable infrastructure include more consistency and reliability in your infrastructure and a simpler, more predictable deployment process

i thought it was D but after reading the doc it's A for sure read this : https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/environmentmgmt-updates-immutable.html

B) Eliminated - This policy replaces all instances with the new version at the same time. It does not maintain full capacity during the deployment, as all the instances are updated simultaneously. This can result in downtime if the deployment fails.

developer's goal of maintaining full capacity and minimizing the impact of a failed deployment, the Immutable deployment policy is the best choice

Both Immutable and Rolling with additional capacity ensure full capacity, however immutable minimizes the impact on user in case of failed deployment, while Rolling with an additional batch impacts is minimal if first batch fails; otherwise, similar to Rolling https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.deploy-existing-version.html#:~:text=The%20following%20table%20compares%20deployment%20method%20properties.

See "Deployment methods" table on https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.deploy-existing-version.html It says only Immutable and Blue/green have minimal Impact of failed deployment. For Rolling with an additional batch impact is Minimal if first batch fails; otherwise, similar to Rolling

https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.deploy-existing-version.html

The answer is the A given that we must have full capacity and we have to minimize the impact of failed deployment. With immutable we can prepare the new environment and switch when it is ready. If there is some issue it is always possible to switch back to the previuos version. I exclude rolling with additional batch because they tried it and the system was down furthemore it is not written to be cost-optimized

Answer D will be correct if the question asks about cost-optimized. Otherwise, question A is more correct

The Immutable deployment policy launches a new set of instances in a separate Auto Scaling group with the new version of the application. After the new instances pass health checks, Elastic Beanstalk switches traffic to them and terminates the old instances. This ensures that full capacity is maintained during deployment and minimizes the impact of a failed deployment.

A similar question was in the exam today. Study this topic carefully.

Answer is A

May be they are already using rolling policy and Ec2 batching and beanstalk mentioned. that is why D is correct answer. A is good option but given situation may be D?

rolling with additional is slow during rollback

A. Rolling with additional batch is slower than Immutable if deploy fails, since the former has to roll back the deployed part, whereas the latter just switches to the old version.

B will cause downtime. C will cause a reduced capacity i.e. partial downtime. They need full capacity so these two won't work. You can also use immutable updates to deploy new versions of your application, as an alternative to rolling deployments. When you configure Elastic Beanstalk to use immutable updates for application deployments, it replaces all instances in your environment every time you deploy a new version of your application. If an immutable application deployment fails, Elastic Beanstalk reverts the changes immediately by terminating the new Auto Scaling group. This can prevent partial fleet deployments, which can occur when a rolling deployment fails after some batches have already completed. https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/environmentmgmt-updates-immutable.html A is my answer.

why not D?