Amazon Web Services DVA-C02 Dumps Questions Answers

The hourly scheduled batch model is causing timeouts because the function must process an ever-growing backlog in a single invocation, which can exceed AWS Lambda’s maximum 15-minute runtime. A best-practice serverless refactor is to switch from “periodic polling” to an event-driven approach where work is split into smaller, independent units that can scale horizontally.

Configuring Amazon S3 Event Notifications to invoke Lambda on each object upload turns each file into its own discrete event. Instead of one long-running invocation that scans and processes many files, Lambda executes quickly per upload and automatically scales with incoming volume (subject to concurrency and downstream limits). This directly reduces processing time per run and eliminates the backlog buildup that leads to timeouts.

The remaining requirement is preventing duplicate processing. S3 event delivery is designed to be highly reliable, and applications should be built with idempotency in mind. Recording processed identifiers (such as a transaction ID, object key + version ID, or an application-level unique ID) in Amazon DynamoDB allows the function to check whether an item has already been processed before performing writes or downstream actions. Using DynamoDB with a conditional write (for example, “insert only if not exists”) is a common pattern to ensure exactly-once effect even when events are delivered more than once.

The other options do not meet the requirements as well: running more frequently (C) or continuously polling (D) still wastes time scanning and can still create duplicate work; moving to a single EC2 instance (B) reduces elasticity and increases operational overhead, and it doesn’t inherently solve deduplication or scaling.

Therefore, A provides scalable, event-driven processing and a straightforward deduplication mechanism.

Comprehensive and Detailed Step-by-Step Explanation:

Option D: Set up Amazon S3 Caching for CodeBuild:

CodeBuild supports S3 caching to store intermediate build artifacts and dependencies. This reduces the time required to download dependencies during subsequent builds, effectively lowering costs and improving build performance.

By using S3 caching, developers can optimize costs without changing the compute type or adding complexity.

Why Other Options Are Incorrect:

Option A: CodeBuild does not have a " reserved capacity fleet " option.

Option B: AWS Lambda cannot be used as the compute mode for CodeBuild projects. CodeBuild uses its own managed build environments.

Option C: CodeBuild already operates on an on-demand basis, so this does not address the need for optimization or reduced provisioning time.

Why Option B is Correct:A customer-managed AWS Key Management Service (KMS) key allows for encryption at rest and provides the ability to rotate the key on demand. This ensures compliance with security requirements for key management and database encryption.

RDS integrates natively with AWS KMS, allowing the use of a customer-managed key for encrypting data at rest.

Key rotation can be managed directly in AWS KMS without needing custom solutions.

Why Other Options are Incorrect:

Option A: AWS KMS managed encryption keys (AWS-owned keys) do not support key rotation on demand.

Option C & D: Storing keys in AWS Secrets Manager with custom rotation is not a recommended approach for database encryption. AWS KMS is designed specifically for secure key management and encryption.

AWS Documentation References:

Encrypting Amazon RDS Resources

AWS Key Management Service (KMS)