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Question 106

A developer uses a single AWS CloudFormation template to configure the test environment and the production environment for an application. The developer handles environment-specific requirements in the CloudFormation template.

The developer decides to update the Amazon EC2 Auto Scaling launch template with new Amazon Machine Images (AMIs) for each environment. The

CloudFormation update for the new AMIs is successful in the test environment, but the update fails in the production environment.

What are the possible causes of the CloudFormation update failure in the production environment? (Choose two.)

    Correct Answer: A, B

    The update failure in the production environment could be due to the new AMIs not fulfilling the specified conditions in the CloudFormation template, as the template might have environment-specific requirements for the AMIs. Another possible cause is that the service quota for the number of EC2 vCPUs in the AWS Region might have been exceeded because during an update, if a resource is replaced, AWS CloudFormation may create new resources before deleting the old ones, potentially pushing the account over its quota limits.

Discussion
habrosOptions: AE

A and E. AMIs can only be used on specific region. Either both environments running on different regions, or permissions insufficient. IAM access deny exception is common issue. Easiest way to allow or deny AWS resources to user. So when user does not have permission to run template on production environment, it’s obvious. Security group is more for networking (open ports). If fail means written wrongly.

KT_Yu

The question never mention different region for prod and test

AswinDe

Selected : CE Coludformation Update stack – Failure reason: 1. Delete stack fails 2. Error parsing parameter when passing a list 3. Insufficient IAM permissions 4. Invalid value or unsupported resource property 5. Resource Quota exceeded 6. Nested stacks are stuck in UPDATE_COMPLETE_CLEANUP_IN_PROGRESS, UPDATE_ROLLBACK_COMPLETE_CLEANUP_IN_PROGRESS, or UPDATE_ROLLBACK_IN_PROGRESS 7. No updates to perform 8. Resource failed to stabilize during a create, update, or delete stack operation 9. Security group does not exist in VPC 10. Update rollback failed 11. Wait condition didn't receive the required number of signals from an Amazon EC2 instance 12. Resource removed from stack but not deleted

KT_Yu

A and B: for B: Verify that you didn't reach a resource quota. For example, the default maximum number of Amazon EC2 On-Demand instances that you can launch is 5. If try to create more Amazon EC2 On-Demand instances than your account quota, the instance creation fails and you receive the error Status=start_failed. To view the default AWS quotas by service, see AWS service quotas in the AWS General Reference. For AWS CloudFormation quotas and tweaking strategies, see AWS CloudFormation quotas. Also, during an update, if a resource is replaced, AWS CloudFormation creates new resource before it deletes the old one. This replacement might put your account over the resource quota, which would cause your update to fail. You can delete excess resources or request a quota increase. https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/troubleshooting.html#troubleshooting-errors-limit-exceeded

Phinx

This makes sense to me.

isshin

Usually you have separate accounts for each environment. And quotas are per account per region.

xdkonorek2Options: CE

A - not possible, conditions are the same for both environments B - not possible, there is no such a quota C - possible, someone deleted SG outside of template D - not possible, CF should detect this change E - possible, IAM permissions could be edited outside of template

pranay_2406Options: AC

A. The new AMIs do not fulfill the specified conditions in the CloudFormation template: The CloudFormation template may have specific conditions or requirements for the AMIs used in the production environment. If the new AMIs do not meet those conditions, the update may fail. C. The security group that is specified in the CloudFormation template does not exist: If the specified security group does not exist in the production environment, the update that references it will fail.

pranay_2406

It's important to note that the other options (B, D, E) are not directly related to the failure of the CloudFormation update for the new AMIs: B. The service quota for the number of EC2 vCPUs in the AWS Region has been exceeded: This quota limitation would impact the ability to launch new EC2 instances, but it wouldn't cause the CloudFormation update to fail specifically due to updating the AMIs. D. CloudFormation does not recognize the template change as an update: If CloudFormation doesn't recognize the template change, it would result in a no-op update rather than a failure.

pranay_2406

E. CloudFormation does not have sufficient IAM permissions to make the changes: If CloudFormation lacks sufficient permissions, it would result in an error or insufficient access message, but it wouldn't specifically cause the update to fail for the new AMIs.

captainpike

A and B IMO this question is based on https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/troubleshooting.html D is impossible because the update fails, meaning it recognized the change and the update ran. I am going to assume the the stack ran succesfully in the first time it ran (creation). So that C and E could not be since the SG worked in the first time and IAM permissions was OK in the first time.

arun00028Options: AE

A and E

XAvenger

"The service quota" does not make sense because we updated Template, there was not any attempt to launch instances => B is incorrect "The security group" was not mentioned before at all.Why would it fail now? I think C is incorrect "does not recognize the template change as an update" => it cannot be. D is incorrect. looks like A and E is the best choice

lozouOptions: AB

Condition on template and limitation on vCPU are existing https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-on-demand-instances.html#ec2-on-demand-instances-limits

sara_exam_topicsOptions: AB

As they mentioned, they just upgrading the AMI, if there was an issue with IAM or security, this issue would be present even before upgrading right.

SyreOptions: AC

A and C are correct. E is very incorrect E is not a likely cause of the CloudFormation update failure, as the CloudFormation update was successful in the test environment. If CloudFormation did not have sufficient IAM permissions, the update would have failed in both the test and production environments.

pancmanOptions: AB

A and B is correct. For those who are saying A&E: If it was an error due to IAM permissions, the update wouldn't succeed in the test environment either. So E can't be correct.

captainpike

Why? Let's say the permisions were granted in the test env and not in prod. Wouldn't that be possible?

captainpike

Changing my mind, but not for the reason of "the update wouldn't succeed in the test environment". I think it cannot be E by the fact that the stack ran succesfully in the 1st time (creation) and now this is just an update. So IAM permissions worked fine.

Rups79Options: AB

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/conditions-section-structure.html https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-capacity-reservations.html

michele_scarOptions: AE

Excluding B, C and D, the only acceptable are A and E. In B, C and D there are information that aren't mentioned in the questions, so useless for the test.

ayoubmkOptions: AB

A and B are more logic for me. Application is already work and we just maded a change so it's dosen't make sense an SG is not available or CF haven't the permissions

HieuTT

A E

gpitOptions: CE

A is probable, but B is more

gpit

Sorry, C is more.