Amazon Web Services Updated SOA-C03 Exam Questions and Answers by mae

In the AWS Cloud Operations and Aurora documentation, when data loss occurs due to human error such as dropped tables, Point-in-Time Recovery (PITR) is the recommended method for restoration. PITR creates a new Aurora cluster restored to a specific time before the failure.

The restored cluster has a new endpoint that must be reconfigured in the application to resume normal operations. AWS does not support performing PITR directly on an existing production database because that would overwrite current data.

Aurora Backtrack (Option A) applies only to Aurora MySQL, not PostgreSQL. Option B is incorrect because PITR cannot be executed in place. Option D refers to an import process from S3, which is unrelated to time-based recovery.

Hence, Option C is correct and follows the AWS CloudOps standard recovery pattern for PostgreSQL workloads.

Amazon EventBridge supports custom event buses for application-specific events. EventBridge archives allow events to be retained and replayed later based on time ranges or event patterns, directly meeting the replay requirement.

Creating a custom event bus provides isolation and governance for application events. The archive preserves events automatically, and EventBridge rules route events to AWS Lambda for processing without custom code.

Options B and C do not properly align with custom event use cases or supported archive behavior. Option D lacks native replay functionality.

Therefore, a custom event bus with an archive and rule is the correct solution.

For IPv4 traffic, private subnets require a NAT gateway in a public subnet to access the internet. NAT gateways must be deployed in public subnets and associated with an Elastic IP address. Private subnet route tables must direct 0.0.0.0/0 traffic to the NAT gateway.

The question states that NAT gateways are incorrectly placed in private subnets, which cannot provide internet access. Deploying NAT gateways in public subnets resolves this issue and restores outbound connectivity to external APIs.

Option A applies only to IPv6. Option B adds unnecessary complexity. Option D is not applicable because external APIs are not AWS services.

When a CloudFormation stack is deleted, CloudFormation’s default behavior is to delete the resources it created, including EC2 instances and attached resources defined in the template. The requirement is explicit: the company must keep the instances and all of the instances’ data even if someone deletes the stack. The CloudFormation mechanism intended for this outcome is the DeletionPolicy attribute, which controls what happens to a resource when the stack is deleted or when the resource is replaced during an update.

Setting DeletionPolicy: Retain on the EC2 instance resource instructs CloudFormation to preserve that resource instead of deleting it during stack deletion. With Retain, CloudFormation removes the resource from stack management but leaves the instance running (and therefore keeps the data that remains on the instance and its configured storage). This directly satisfies the requirement because the instance is not terminated as part of stack deletion.

Option A is incorrect for EC2 instances because Snapshot is applicable to certain resource types (commonly storage and database resources where snapshot semantics exist), not as a general “keep my instance” control for EC2 instance resources. Options B and C (DLM and AWS Backup) are valuable for backup and recovery strategies, but they do not prevent CloudFormation from terminating the instances when the stack is deleted. Backups could help restore later, but the requirement is to keep the original instances and their data even after deletion of the stack.

Therefore, the correct solution is to set DeletionPolicy to Retain for the EC2 instance resource in the CloudFormation template.