Amazon Web Services Updated DVA-C02 Exam Questions and Answers by tudor

To meet the requirement:

Users must be able to upload (PutObject) and read (GetObject) files but not delete them.

Option D ensures users cannot delete files by omitting the s3:DeleteObject action while allowing s3:GetObject and s3:PutObject.

Option A: Includes s3:DeleteObject, which allows users to delete files and does not meet the requirement.

Option B: Contains unrelated actions like CreateBucket, which is not relevant here.

Option C: Adds s3:PutObjectRetention, which is unnecessary and does not restrict DeleteObject.

The correct answer is C. Use an AWS Lambda function that is invoked by an Amazon EventBridge scheduled event.

C. Use an AWS Lambda function that is invoked by an Amazon EventBridge scheduled event. This is correct. AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. Lambda runs your code on a high-availability compute infrastructure and performs all of the administration of the compute resources, including server and operating system maintenance, capacity provisioning and automatic scaling, and logging1. Amazon EventBridge is a serverless event bus service that enables you to connect your applications with data from a variety of sources2. EventBridge can create rules that run on a schedule, either at regular intervals or at specific times and dates, and invoke targets such as Lambda functions3. This solution meets the requirements of creating a small application that makes the same API call once each day at a designated time, without requiring any infrastructure in the AWS Cloud or any operational overhead.

A. Use a Kubernetes cron job that runs on Amazon Elastic Kubernetes Service (Amazon EKS). This is incorrect. Amazon EKS is a fully managed Kubernetes service that allows you to run containerized applications on AWS4. Kubernetes cron jobs are tasks that run periodically on a given schedule5. This solution could meet the functional requirements of creating a small application that makes the same API call once each day at a designated time, but it would not be the most operationally efficient manner. The company would need to provision and manage an EKS cluster, which would incur additional costs and complexity.

B. Use an Amazon Linux crontab scheduled job that runs on Amazon EC2. This is incorrect. Amazon EC2 is a web service that provides secure, resizable compute capacity in the cloud6. Crontab is a Linux utility that allows you to schedule commands or scripts to run automatically at a specified time or date7. This solution could meet the functional requirements of creating a small application that makes the same API call once each day at a designated time, but it would not be the most operationally efficient manner. The company would need to provision and manage an EC2 instance, which would incur additional costs and complexity.

D. Use an AWS Batch job that is submitted to an AWS Batch job queue. This is incorrect. AWS Batch enables you to run batch computing workloads on the AWS Cloud8. Batch jobs are units of work that can be submitted to job queues, where they are executed in parallel or sequentially on compute environments9. This solution could meet the functional requirements of creating a small application that makes the same API call once each day at a designated time, but it would not be the most operationally efficient manner. The company would need to configure and manage an AWS Batch environment, which would incur additional costs and complexity.

The workload is explicitly very I/O intensive and requires reading the same file multiple times. Reading repeatedly from S3 across the network will introduce latency and repeated network I/O. For best performance, the function should download the file once to fast local storage and perform all repeated reads locally.

AWS Lambda provides ephemeral storage mounted at /tmp. AWS allows increasing this ephemeral storage beyond the default size. Because the files are at most 2 GB, the developer can configure the Lambda function’s ephemeral storage to 2 GB and copy each S3 object into /tmp before processing. This converts repeated network reads into repeated local filesystem reads, which is significantly faster and more consistent for I/O-heavy workloads.

Option D (read directly from S3) is the least optimized because each pass over the file requires additional network I/O and S3 GET requests.

Option A is not feasible: Lambda cannot directly attach and manage an EBS volume like an EC2 instance can.

Option B is not applicable: ENA is an EC2 networking feature; Lambda networking is managed by the service and does not allow attaching ENAs for performance tuning in that way.

Because the files are disposable after processing, using ephemeral /tmp storage is also cost-effective and operationally simple, and it is aligned with the “process once per file” pattern.

Therefore, increase Lambda ephemeral storage and copy the video into /tmp for repeated reads.