SAA-C03 Question 40
Select 2A company is designing a serverless application using AWS Lambda and Amazon S3. The application needs to process image files uploaded to an S3 bucket. Once an image is uploaded, the Lambda function should be triggered automatically to generate thumbnails for the image. The solution should be cost-effective and scalable. Which configuration steps should be taken to meet these requirements?
- A
Configure the S3 bucket to use Event Notifications to trigger the Lambda function on the 's3:ObjectCreated' event.
- B
Set up an Amazon S3 Lifecycle policy to transition objects to Amazon S3 Glacier after processing.
- C
Write an IAM policy that grants the Lambda function permissions to read objects from the S3 bucket and write thumbnails back to the bucket.
- D
Enable cross-region replication on the S3 bucket to enhance data durability and availability.
- E
Create an Amazon SQS queue to buffer notifications from S3 before invoking the Lambda function.
Show answer and explanation
Correct answers: A, C
Explanation
To meet the requirements of a cost-effective, scalable image processing system, AWS S3 Event Notifications should be configured to trigger the Lambda function whenever an image is uploaded. Additionally, the Lambda function must have sufficient IAM permissions to interact with the S3 bucket. The other options, such as lifecycle policies, cross-region replication, or SQS, are unnecessary or irrelevant for this specific use case.
- A. Correct.
Correct: Configuring S3 Event Notifications to trigger the Lambda function on 's3:ObjectCreated' ensures the Lambda function is invoked automatically when a new image is uploaded.
- B. Incorrect.
Incorrect: While S3 Lifecycle policies are useful for managing object storage costs, they are not relevant for triggering or processing Lambda functions in this scenario.
- C. Correct.
Correct: The Lambda function needs appropriate IAM permissions to read the uploaded images and write the generated thumbnails back to the S3 bucket.
- D. Incorrect.
Incorrect: Cross-region replication is used for replicating data across regions for durability or compliance purposes, and it does not contribute to the functional requirements of this solution.
- E. Incorrect.
Incorrect: An SQS queue is not necessary here because S3 Event Notifications can directly invoke Lambda functions without the need for a buffering mechanism in this scenario.