AWS Certified Developer Associate · Free Practice Question Medium
Question 49
A Developer has completed some code updates and needs to deploy the updates to an Amazon Elastic Beanstalk environment. The environment includes twelve Amazon EC2 instances and there can be no reduction in application performance and availability during the update.
Which deployment policy is the most cost-effective choice to suit these requirements?
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A
All at once
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B
Rolling with additional batch
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C
Immutable
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D
Rolling
Reveal correct answer
Correct answer: B
Explanation
AWS Elastic Beanstalk provides several options for how deployments are processed, including deployment policies and options that let you configure batch size and health check behavior during deployments.
Each deployment policy has advantages and disadvantages and it’s important to select the best policy to use for each situation. The following tables summarizes the different deployment policies:
The “rolling with additional batch” policy will add an additional batch of instances, updates those instances, then move onto the next batch.
Rolling with additional batch:
Like Rolling but launches new instances in a batch ensuring that there is full availability.
Application is running at capacity.
Can set the bucket size.
Application is running both versions simultaneously.
Small additional cost.
Additional batch is removed at the end of the deployment.
Longer deployment.
Good for production environments.
For this scenario there can be no reduction in application performance and availability during the update. The question also asks for the most cost-effective choice.
Therefore, the “rolling with additional batch” is the best choice as it will ensure fully availability of the application but minimize cost as the additional batch size can be kept small.
CORRECT: "Rolling with additional batch" is the correct answer.
INCORRECT: "Rolling" is incorrect as this will result in a reduction in capacity as there is no additional batch of instances introduced to the environment. This is a better choice if speed is required and a reduction in capacity of a batch size is acceptable.
INCORRECT: "All at once" is incorrect as this will take the application down and cause a complete outage of the application during the update.
INCORRECT: "Immutable" is incorrect as this is the most expensive option as it doubles capacity with a whole new set of instances attached to a new ASG.
References:
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.deploy-existing-version.html
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.rolling-version-deploy.html
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