Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 171 discussion

Option D is similar to option B in that it uses Amazon API Gateway to handle the API requests, but it also includes an EC2 instance to perform the tax computations. However, using an EC2 instance in this way is less scalable and less elastic than using AWS Lambda to perform the computations. An EC2 instance is a fixed resource and requires manual scaling and management, while Lambda is an event-driven, serverless compute service that automatically scales with the number of requests, making it more suitable for handling variable workloads and reducing response times during high traffic periods. Additionally, Lambda is more cost-efficient than EC2 instances, as you only pay for the compute time consumed by your functions, making it a more cost-effective solution.

Option B. Though D is also possible B is more scalable as Lambda will autoscale to meet the dynamic load.

Both API Gateway and Lambda are suitable as they are scalable.

Ans B - I was going for option D... but then I saw bullrem's response (1 year, 9 mth ago): "Option D is similar to option B in that it uses Amazon API Gateway to handle the API requests, but it also includes an EC2 instance to perform the tax computations. However, using an EC2 instance in this way is less scalable and less elastic than using AWS Lambda to perform the computations."

b. easy

Option B: Lamda = scalable and elastic

Option B leverages AWS Lambda, which is a serverless compute service that automatically scales in response to incoming requests. When a request is made to the API hosted on Amazon API Gateway, API Gateway triggers the associated AWS Lambda function, passing the item names as input parameters. The Lambda function then performs the tax computations based on the provided item names. AWS Lambda automatically manages the compute capacity, ensuring that there is no need to provision or manage servers. This serverless architecture offers scalability and elasticity, as Lambda functions can scale out to handle a larger number of inquiries during the holiday season and scale in during periods of lower demand. Additionally, AWS Lambda is a fully managed service, reducing operational overhead for the company.

The thing that bothers me about B is that the request sends the name and then based on the name, the tax is calculated. How do you calculate a value e.g. tax if you just have a name...

EC2 without autoscaling is not elastic so A, C & D won't be suitable. B uses AWS Lambda which is elastic and scalable by design.

Though EC2 can scale (even if less flexible than Lambda), neither A, C nor D involve scaling. All these answers are about a single EC2 instance or a pair of EC2 instances. The only answer that includes scaling and elasticity is B.

scalable and elastic = serverless = API gateway and AWS Lambda

in 002 answer is B. Why is that?

Options A, C, and D involve EC2 instances, which are not as inherently scalable and elastic as serverless AWS Lambda functions, and they would require more manual management and operational overhead. Therefore, option B is the most appropriate choice for a scalable and elastic API solution.

REST API using Amazon API Gateway and integrating it with AWS Lambda (option B) is the recommended approach to achieve a scalable and elastic solution for the company's API during the holiday season. ________ No good EC2 in this case using an EC2 instance in this way is less scalable and less elastic than using AWS Lambda to perform the computations

scalable and elastic = serverless = API gateway and AWS Lambda

B) Design a REST API using Amazon API Gateway that accepts the item names. API Gateway passes item names to AWS Lambda for tax computations. This option provides the most scalable and elastic solution: API Gateway handles creating the REST API frontend to receive requests Lambda functions scale automatically to handle spikes in traffic during peak seasons No servers to manage for the computations, providing high scalability

Option A (hosting an API on an Amazon EC2 instance) would require manual management and scaling of the EC2 instances, making it less scalable and elastic compared to a serverless solution. Option C (creating an Application Load Balancer with EC2 instances for tax computations) also involves manual management of the instances and does not offer the same level of scalability and elasticity as a serverless solution. Option D (designing a REST API using API Gateway and connecting it with an API hosted on an EC2 instance) adds unnecessary complexity and management overhead. It is more efficient to directly integrate API Gateway with AWS Lambda for tax computations. Therefore, designing a REST API using Amazon API Gateway and integrating it with AWS Lambda (option B) is the recommended approach to achieve a scalable and elastic solution for the company's API during the holiday season.