Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 10 discussion

B because FIFO is made for that specific purpose

Should be B because SQS FIFO queue guarantees message order.

Has to be FIFO queue for this requirement

SQS FIFO as if want to maintain order of messages recieved to order of messages sent. It is like QUEUE data structutre in DSA

SQS FIFO gurantees message order.

Explanation: FIFO Queues: Amazon SQS FIFO queues are specifically designed to maintain the order of messages. This ensures that messages are processed in the exact sequence they were sent, which is crucial for order processing in an e-commerce application. Why other options are less suitable: A. Amazon SNS: SNS is a publish-subscribe service. It doesn't guarantee message order. C. API Gateway Authorizer: Authorizers are used for authentication and authorization, not for managing message order. D. Amazon SQS Standard Queue: Standard SQS queues do not guarantee message order.

Standard queues ensure at-least-once message delivery, but due to the highly distributed architecture, more than one copy of a message might be delivered, and messages may occasionally arrive out of order.

AnswerB - SQS FIFO queues ensure that messages are processed in the order they are received, which perfectly matches the requirement of maintaining order.

A lot of answers seem to not match the most voted. i'm confused which to follow.

Explanation: To ensure that orders are processed in the order that they are received, the best solution is to use an Amazon SQS FIFO (First-In-First-Out) queue. This type of queue maintains the exact order in which messages are sent and received. In this case, the application can send information about new orders to an Amazon API Gateway REST API, which can then use an API Gateway integration to send a message to an Amazon SQS FIFO queue for processing. The queue can then be configured to invoke an AWS Lambda function to perform the necessary processing on each order. This ensures that orders are processed in the exact order in which they are received.

Keywords: - Orders are processed in the order that they are received. A: Incorrect - SNS just for notification like send email, SMS. It don't retain the data in the queue and it's used pub-sub pattern. B: Correct - SQS FIFO will help message process in order. FIFO -> first in first out. C: Incorrect - with this solution we will create blocker app not good app =)) D: Incorrect - SQS standard don't guarantee the order.

Explanation: - Amazon API Gateway will be used to receive the orders from the web application. - Instead of directly processing the orders, the API Gateway will integrate with an Amazon SQS FIFO queue. - FIFO (First-In-First-Out) queues in Amazon SQS ensure that messages are processed in the order they are received. - By using a FIFO queue, the order processing is guaranteed to be sequential, ensuring that the first order received is processed before the next one. - An AWS Lambda function can be configured to be triggered by the SQS FIFO queue, processing the orders as they arrive

A. This option could be correct if we use SNS FIFO option, but this is not the case stated in the question. Additionally, this task is more efficient done by a queue than a subscription service. So, this option is not correct. B. We use a queue, which is efficient processing messages. Additionally, it preserves the order since it is a FIFO queue. Meanwhile we don’t have any kind of messages throughput limitation, this option is correct. C. This option discards any messages that are still processing, which is not a good solution. D. Same option as B but using a normal queue, which does not preserve the order. Incorrect.

FIFO is crucial to ensuring the solution works. Two answers use SQS and the author has differentiated between these option by specifically stating in option B “FIFO” On the other hand, SNS also has a FIFO option but the author has chosen to not state that in answer A. If the author had said in option A: “…with FIFO” then A could have been a viable answer. Therefore it has to be Ans B (not A as the author recommends).

FIFO is crucial to ensuring the solution works. Two answers (B & D) use SQS and the author has differentiated between these by specifically stating in answer B “FIFO”. On the other hand (answer A), SNS also has a FIFO option but the author has chosen to not state that in answer A. If the author had been consistent and said in answer A: “…with FIFO” then A could have been a viable answer. Therefore it has to be Ans B (not A as the author recommends).

FIFO ensures message order

B. SQS FIFO as order of processing should be same as order of receiving