AWS DevOps Engineer Professional Practice Test

In a scenario where high read performance is needed from DynamoDB Streams, what is the optimal approach?

1. Using multiple Lambda functions for each stream

2. Implementing a direct read from DynamoDB

3. Using a fan-out approach with SNS

4. Increasing the read throughput directly on DynamoDB

The correct answer is: Using a fan-out approach with SNS

The optimal approach to achieve high read performance from DynamoDB Streams is by employing a fan-out mechanism using Amazon Simple Notification Service (SNS). This method allows for the simultaneous distribution of stream events to multiple subscribers, which helps to alleviate the pressure on individual consumers at scale. When a change occurs in a DynamoDB table, the event is published to an SNS topic, which then can trigger multiple Lambda functions or other services that can process the stream events concurrently. This architecture maximizes the throughput and decreases latency because it enables multiple processing units to handle the data in parallel, rather than relying on a single consumer that could become a bottleneck. It also enhances the system's responsiveness, as multiple consumers can process the streams at the same time, leading to quicker event handling. Other approaches may not provide the same level of efficiency or scalability. For instance, while using multiple Lambda functions could help distribute the load, it does not achieve the same level of fan-out as SNS, potentially leading to uneven processing. Directly reading from DynamoDB might not leverage the stream's architecture effectively for capturing change events. Simply increasing read throughput on DynamoDB can lead to higher costs and does not inherently streamline the processing of stream events. Therefore, the fan-out approach using SNS is