Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 207 discussion

A does not meet the "without impacting existing users" requirement B does not help with writing (DAX caches reads) C does not help with writing (index could increase read performance only) D decouples writing from front-end, which is acceptable because it is "an asynchronous API" anyway

The key here is "Losing user requests" sqs messages will stay in the queue until it has been processed

D bro. Believe

This solution can handle bursts of incoming requests more effectively and reduce the chances of losing requests due to DynamoDB capacity limitations. The Lambda can be configured to retrieve messages from the SQS and write them to DynamoDB at a controlled rate, allowing DynamoDB to handle the requests within its provisioned capacity. This approach provides resilience to spikes in traffic and ensures that requests are not lost during periods of high demand.

This solution can handle bursts of incoming requests more effectively and reduce the chances of losing requests due to DynamoDB capacity limitations. The Lambda can be configured to retrieve messages from the SQS and write them to DynamoDB at a controlled rate, allowing DynamoDB to handle the requests within its provisioned capacity. This approach provides resilience to spikes in traffic and ensures that requests are not lost during periods of high demand. A. It limits can help control the request rate, but it may lead to an increase in errors and affect the user experience. Throttling alone may not be sufficient to address the availability issues and prevent the loss of requests. B. It can improve read performance but does not directly address the availability issues and loss of requests. It focuses on optimizing read operations rather than buffering writes. C. It may help with querying the user requests efficiently, but it does not directly solve the availability issues or prevent the loss of requests. It is more focused on data retrieval rather than buffering writes.

DAX is for reads

D because SQS is the cheapest way. First 1,000,000 requests are free each month. Question states: "The company provisioned as much DynamoDB throughput as its budget allows"

D is more likely to fix this problem as SQS queue has the ability to wait (buffer) for consumer to notify that the request or message has been processed.

To address the issue of lost user requests and improve the availability of the API, the solutions architect should use the Amazon Simple Queue Service (Amazon SQS) queue and Lambda to buffer writes to DynamoDB. Option D (correct answer) By using an SQS queue and Lambda, the solutions architect can decouple the API front end from the processing microservices and improve the overall scalability and availability of the system. The SQS queue acts as a buffer, allowing the API front end to continue accepting user requests even if the processing microservices are experiencing high workloads or are temporarily unavailable. The Lambda function can then retrieve requests from the SQS queue and write them to DynamoDB, ensuring that all user requests are stored and processed. This approach allows the company to scale the processing microservices independently from the API front end, ensuring that the API remains available to users even during periods of high demand.

I would go to B : https://aws.amazon.com/es/blogs/database/amazon-dynamodb-accelerator-dax-a-read-throughwrite-through-cache-for-dynamodb/

D is correct answer

D. Use the Amazon Simple Queue Service (Amazon SQS) queue and Lambda to buffer writes to DynamoDB.

Option D is right answer

Why not B? DAX. "When you’re developing against DAX, instead of pointing your application at the DynamoDB endpoint, you point it at the DAX endpoint, and DAX handles the rest. As a read-through/write-through cache, DAX seamlessly intercepts the API calls that an application normally makes to DynamoDB so that both read and write activity are reflected in the DAX cache." https://aws.amazon.com/es/blogs/database/amazon-dynamodb-accelerator-dax-a-read-throughwrite-through-cache-for-dynamodb/

yeah I though the answer is also DAX.

Using SQS should be the answer.

Answer d