Amazon Web Services DVA-C02 Exam With Confidence Using Practice Dumps

Amazon DynamoDB is a fully managed NoSQL database service that can store and retrieve any amount of data with high availability and performance. DynamoDB can handle concurrent requests from multiple IoT devices without throttling or data loss. To prevent duplicate requests from causing inconsistencies or data loss, the Lambda function can use DynamoDB conditional writes to check if the unique identifier for each request already exists in the table before processing the request. If the identifier exists, the function can skip or abort the request; otherwise, it can process the request and store the identifier in the table. Reference: Using conditional writes

The goal is minimal downtime during deployment and fast rollback if problems occur. In Elastic Beanstalk, the approach that best satisfies both is a blue/green deployment.

With blue/green, the developer deploys the new application version to a separate environment (green) while the current production environment (blue) continues serving traffic. Once validation is complete (health checks, smoke tests), the developer performs a controlled CNAME swap (or routing switch) so traffic shifts from blue to green with near-zero downtime. This reduces risk because the existing environment remains intact and can immediately resume traffic if issues are detected.

Rollback time is also minimized because reverting is simply switching traffic back to the original environment (swap back), rather than rolling back changes across the same environment.

Why the other options are weaker:

All-at-once (C) introduces the highest downtime and risk because it replaces all instances at once, potentially taking the application fully offline and making rollback slower.

Rolling (A) reduces downtime compared to all-at-once, but instances are still updated in-place; if issues appear mid-deployment, rollback is more complex and slower than swapping environments.

Rolling with additional batches (B) can further reduce capacity impact by adding extra instances during deployment, but rollback still involves reversing updates in the same environment and is typically slower than blue/green.

Therefore, deploying to a new environment and using blue/green provides the least downtime and the fastest rollback.

To rotate database credentials without downtime, Secrets Manager recommends the alternating users (dual user) rotation strategy. With a single-user strategy, Secrets Manager changes the password for the same database user that the application is actively using. If the application continues using cached/old credentials during rotation, authentication failures and downtime can occur.

With the alternating users strategy, two database users exist (often named something like appuser and appuser_clone). Secrets Manager alternates which user is “active” in the secret. During rotation, Secrets Manager updates the inactive user’s password, verifies it, updates the secret to point to the newly updated user, and then (optionally) retires the old credentials. This approach minimizes disruption because there is always one known-good credential set while the other is being updated.

The question specifically requires regular rotation using Secrets Manager. That is achieved by enabling automatic rotation on the secret with a schedule (for example, every 30/60/90 days). Automatic rotation invokes the rotation Lambda (AWS-provided or configured) and performs the workflow without manual intervention.

Option D combines both requirements: automatic rotation plus the alternating users strategy for high availability and no downtime.

Option B mentions alternating users but “managed rotation” is not the standard term used in these choices as the primary differentiator—automatic rotation is the necessary capability to rotate regularly without manual effort.

Options A and C (single user) are more likely to cause downtime during rotation.

Therefore, configure automatic rotation with the alternating users rotation strategy.