Free Amazon Web Services DOP-C02 Practice Exam with Questions & Answers | Set: 5

The Auto Scaling group service-linked role must have a specific grant in the source account in order to decrypt the encrypted AMI. This is because the service-linked role does not have permissions to assume the default IAM role in the source account.

The following steps are required to meet the requirements:

In the source account, copy the unencrypted AMI to an encrypted AMI. Specify the KMS key in the copy action.

In the source account, create a KMS grant that delegates permissions to the Auto Scaling group service-linked role in the target account.

In the source account, share the encrypted AMI with the target account.

In the target account, attach the KMS grant to the Auto Scaling group service-linked role.

The first three steps are the same as the steps that I described earlier. The fourth step is required to grant the Auto Scaling group service-linked role permissions to decrypt the AMI in the target account.

Option A is incorrect because increasing the memory of the Lambda function does not address the root cause of the problem, which is that the Lambda function is not triggered by the S3 event source. Increasing the memory of the Lambda function might improve its performance or reduce its execution time, but it does not affect its invocation. Moreover, increasing the memory of the Lambda function might incur higher costs, as Lambda charges based on the amount of memory allocated to the function.

Option B is correct because creating a resource policy on the Lambda function to grant Amazon S3 the permission to invoke the Lambda function for the S3 bucket is a necessary step to configure an S3 event source. A resource policy is a JSON document that defines who can access a Lambda resource and under what conditions. By granting Amazon S3 permission to invoke the Lambda function, the company ensures that the Lambda function runs when a new object is created or an existing object is modified in the S3 bucket1.

Option C is incorrect because configuring an Amazon Simple Queue Service (Amazon SQS) queue as an On-Failure destination for the Lambda function does not help with triggering the Lambda function. An On-Failure destination is a feature that allows Lambda to send events to another service, such as SQS or Amazon Simple Notification Service (Amazon SNS), when a function invocation fails. However, this feature only applies to asynchronous invocations, and S3 event sources use synchronous invocations. Therefore, configuring an SQS queue as an On-Failure destination would have no effect on the problem.

Option D is incorrect because provisioning space in the /tmp folder of the Lambda function does not address the root cause of the problem, which is that the Lambda function is not triggered by the S3 event source. Provisioning space in the /tmp folder of the Lambda function might help with processing large files from the S3 bucket, as it provides temporary storage for up to 512 MB of data. However, it does not affect the invocation of the Lambda function.

Amazon GuardDuty provides built-in, fully managed threat detection for AWS accounts and workloads, including automatic detection of cryptocurrency mining activity, compromised EC2 instances, command-and-control traffic patterns, and anomalous behaviors. GuardDuty includes multiple threat identifiers such as EC2:CryptoCurrencyActivity.BitcoinToolDetected and EC2:UnauthorizedAccess.CryptoMining. Because this capability is native and requires no custom detection logic, it provides the lowest development and operational overhead compared to alternatives.

When GuardDuty generates a finding, it publishes the event automatically to Amazon EventBridge. The DevOps engineer can create an EventBridge rule that matches the specific mining-related finding types. The target of the rule is an AWS Lambda function that parses instance details from the finding and calls TerminateInstances on the affected EC2 instance.

This enables real-time automated remediation without needing recurring scans, log parsing, or complex data queries.

Options A and B require building custom detection pipelines and maintaining periodic Lambda polling, increasing long-term complexity. Option D (Security Hub) aggregates findings but still relies on GuardDuty for detection, adding unnecessary overhead.

Therefore, GuardDuty + EventBridge + Lambda termination is the easiest, quickest, and most AWS-recommended solution following incident-response best practices.

Container restart failures require detailed observability into pod-level, node-level, and container-level metrics and logs. CloudWatch Container Insights is purpose-built for Kubernetes operational diagnostics and provides granular visibility into CPU, memory, network I/O, disk I/O, container restarts, OOM kills, throttling, pod lifecycle issues, and Kubernetes control plane behaviors.

The CloudWatch Observability add-on deploys Fluent Bit and the CloudWatch Agent directly into the EKS cluster as DaemonSets. These components automatically collect:

Container logs

Pod metrics

Node metrics

Cluster events

OOM errors

CrashLoopBackOff restart cycles

Control plane request anomalies

With this data, the DevOps engineer can easily identify misconfigurations, resource bottlenecks, unhealthy nodes, failing containers, or image pull issues.

Option A (dashboards only) lacks per-container diagnostic data.

Option B (CloudTrail) only logs API calls — not useful for restart debugging.

Option C (CloudTrail Insights) only detects anomalous API usage, not container failures.

Therefore, CloudWatch Container Insights is the correct and AWS-recommended solution for diagnosing container restart failures in EKS.

The latency in processing and ingesting logs can be caused by several factors, such as the throughput of the Kinesis data stream, the concurrency of the Lambda function, and the configuration of the event source mapping. To reduce the latency, the following steps can be taken:

Create a data stream consumer with enhanced fan-out. Set the Lambda function that processes the logs as the consumer. This will allow the Lambda function to receive records from the data stream with dedicated throughput of up to 2 MB per second per shard, independent of other consumers1. This will reduce the contention and delay in accessing the data stream.

Increase the ParallelizationFactor setting in the Lambda event source mapping. This will allow the Lambda service to invoke more instances of the function concurrently to process the records from the data stream2. This will increase the processing capacity and reduce the backlog of records in the data stream.

Configure reserved concurrency for the Lambda function that processes the logs. This will ensure that the function has enough concurrency available to handle the increased load from the data stream3. This will prevent the function from being throttled by the account-level concurrency limit.

The other options are not effective or may have negative impacts on the latency. Option D is not suitable because increasing the batch size in the Kinesis data stream will increase the amount of data that the Lambda function has to process in each invocation, which may increase the execution time and latency4. Option E is not advisable because turning off the ReportBatchItemFailures setting in the Lambda event source mapping will prevent the Lambda service from retrying the failed records, which may result in data loss. Option F is not necessary because increasing the number of shards in the Kinesis data stream will increase the throughput of the data stream, but it will not affect the processing speed of the Lambda function, which is the bottleneck in this scenario.

1: Using AWS Lambda with Amazon Kinesis Data Streams - AWS Lambda

2: AWS Lambda event source mappings - AWS Lambda

3: Managing concurrency for a Lambda function - AWS Lambda

4: AWS Lambda function scaling - AWS Lambda

AWS Lambda event source mappings - AWS Lambda

Scaling Amazon Kinesis Data Streams with AWS CloudFormation - Amazon Kinesis Data Streams

https://docs.aws.amazon.com/systems-manager/latest/userguide/sysman-managed-instance-activation.html

Comprehensive and Detailed Explanation From Exact Extract of DevOps Engineer documents only:

During an Amazon ECS service deployment, if tasks fail the Elastic Load Balancing target group health checks, Amazon ECS considers those tasks unhealthy and stops and replaces them. This behavior can cause the deployment to remain incomplete because healthy replacement tasks never become available.

Also, if an essential container in the task exits, the entire task stops. Since the question states that the new tasks enter a stopped state soon after launch, an essential container failure is a direct and highly likely cause.

Why the other options are incorrect:

B. The IAM role used by the DevOps engineer to update the ECS service does not need RunTask permission for the tasks to remain running after launch. A permission issue here would more likely affect the update action itself rather than cause launched tasks to stop shortly afterward.

C. Although CloudWatch Logs configuration problems can affect logging, the missing log group is not the most likely direct reason for ECS tasks to repeatedly stop in this deployment scenario.

D. The task role provides permissions to the application code running inside the container. It is not the role primarily responsible for launching the task. Task startup is typically related to the task execution role, ECS service behavior, container health, and load balancer checks.

Use custom constructs to encapsulate reusable patterns and deploy separate stacks per microservice for better isolation and environment-specific params. Apply tags programmatically at the app/stack/construct scope with Tags so all resources inherit them. This is the recommended CDK pattern to minimize duplication and maximize reusability.