AWS Certified Associate SOA-C02 Reddit Questions

AWS CloudFormation StackSets Overview:

StackSets allows for deployment of CloudFormation stacks across multiple AWS accounts and Regions.

A stack instance in the "OUTDATED" status indicates that the stack template or parameters differ between the StackSet and the stack instance.

Why the Stack Instance Fails:

The "OUTDATED" status occurs when the stack operation (creation or update) was not successfully completed in a specific Region.

In this case, the most likely reason is that the stack has not yet been deployed in the specified Region.

Steps to Resolve:

Check the deployment status in the CloudFormation StackSets Console.

Identify the Region where the stack is in the "OUTDATED" status.

Retry the stack deployment for that Region by running a stack set update or stack instance operation.

Why Other Options Are Incorrect:

A: Local template changes do not impact CloudFormation unless submitted to AWS. This is unrelated to StackSets.

B: While creating a global resource might fail, it would result in an error status (e.g., "FAILED"), not "OUTDATED."

D: Using an old API version would cause errors in the API request, not affect the stack instance status.

References:

AWS CloudFormation StackSets Documentation

Troubleshooting StackSet Issues

Scaling Policies in Auto Scaling:

When multiple scaling policies trigger at the same time, each policy is executed independently.

If both policies are set to add 5 instances when CPU utilization reaches 80%, they will both be executed when the threshold is met.

Therefore, the total number of instances added will be the sum of the instances specified in both policies.

In this case, 5 instances from one policy and 5 instances from the other policy will result in a total of 10 instances being added.

Steps to Configure and Verify Scaling Policies:

Go to the AWS Management Console.

Navigate to EC2 and select "Auto Scaling Groups."

Select your Auto Scaling group and review the scaling policies.

Ensure that both scaling policies are configured to trigger at 80% CPU utilization.

Monitor the Auto Scaling group's activity to verify the addition of instances when the CPU utilization threshold is reached.

You are correct that an A record typically points to an IP address. However, in the case of an Application Load Balancer (ALB), you cannot use an A record with an IP address because the IP addresses of an ALB can change over time. Instead, you can use an alias record to point to the DNS name of the ALB. An alias record is a Route 53 extension to DNS that allows you to route traffic to selected AWS resources, such as an ALB, by using a friendly DNS name, such as example.com, instead of the resource’s IP address or DNS name.

To monitor traffic flows between ECS tasks, you need to use VPC Flow Logs and specify the awsvpc network mode in the task definition.

VPC Flow Logs:

VPC Flow Logs capture information about the IP traffic going to and from network interfaces in your VPC.

Enable VPC Flow Logs on the elastic network interfaces (ENIs) used by the ECS tasks.

awsvpc Network Mode:

The awsvpc network mode gives each task its own ENI, allowing for more granular network monitoring and security controls.

This mode is required to capture detailed traffic flow information for each ECS task.

References:

VPC Flow Logs

Amazon ECS Task Networking