Easy — DVA-C02 Practice Quiz

Question 1

A developer is building a web application that stores user session tokens in a DynamoDB table. Each session should automatically be removed 24 hours after creation to reduce storage costs and keep the table clean. The developer wants a solution that requires minimal ongoing operational effort and no scheduled cleanup jobs. Which approach should the developer implement?

Accepted Answer

Add an attribute containing the expiration time as a Unix epoch timestamp and enable Time to Live (TTL) on that attribute.

Answer

Create an Amazon EventBridge scheduled rule that triggers a Lambda function hourly to scan the table and delete expired items.

Answer

Store the creation timestamp and configure a DynamoDB Stream to delete each item 24 hours after it is written.

Answer

Enable a 24-hour object lifecycle policy on the DynamoDB table to expire items automatically.

Question 2

A developer is building an order-processing feature. When a customer submits an order through a web frontend, the frontend calls a Lambda function directly using the AWS SDK and must display the calculated order total to the customer immediately. The developer wants the SDK call to wait for the function to finish and return its result in the response. Which Lambda invocation type should the developer use?

Accepted Answer

Invoke the function with the InvocationType set to RequestResponse (synchronous).

Answer

Invoke the function with the InvocationType set to Event (asynchronous).

Answer

Invoke the function with the InvocationType set to DryRun.

Answer

Configure an event source mapping so Lambda polls for the order and returns the result.

Question 3

A development team builds a serverless application using AWS SAM. Before deploying to the cloud, they want to run and debug their Lambda function handler logic locally, invoking it with a sample API Gateway event payload to verify the response, without incurring AWS charges or deploying anything. Which approach best supports this requirement during development?

Accepted Answer

Use the AWS SAM CLI to invoke the function locally with 'sam local invoke', passing a generated event file so the handler runs in a local container.

Answer

Deploy the stack with 'sam deploy' to a dedicated test account and invoke the function through the API Gateway endpoint using curl.

Answer

Enable AWS X-Ray tracing on the deployed function and replay recorded traces to validate the handler logic.

Answer

Configure provisioned concurrency on the function so it stays warm, then invoke it repeatedly from the Lambda console test tab.