AWS Certified Solutions Architect – Professional — Question 338

A Solutions Architect is building a solution for updating user metadata that is initiated by web servers. The solution needs to rapidly scale from hundreds to tens of thousands of jobs in less than 30 seconds. The solution must be asynchronous always avertable and minimize costs.
Which strategies should the Solutions Architect use to meet these requirements?

Answer options

• A. Create an AWS SWF worker that will update user metadata updating web application to start a new workflow for every job.
• B. Create an AWS Lambda function that will update user metadata. Create an Amazon SOS queue and configure it as an event source for the Lambda function. Update the web application to send jobs to the queue.
• C. Create an AWS Lambda function that will update user metadata. Create AWS Step Functions that will trigger the Lambda function. Update the web application to initiate Step Functions for every job.
• D. Create an Amazon SQS queue. Create an AMI with a worker to check the queue and update user metadata. Configure an Amazon EC2 Auto Scaling group with the new AMI. Update the web application to send jobs to the queue.

Correct answer: B

Explanation

Using Amazon SQS combined with AWS Lambda provides a highly available, asynchronous, and cost-effective solution that can rapidly scale to handle tens of thousands of concurrent executions in seconds. AWS Step Functions and AWS SWF introduce unnecessary orchestration overhead and higher costs for simple metadata updates. Using Amazon EC2 Auto Scaling with an AMI is too slow to scale from hundreds to tens of thousands of jobs within the required 30-second window.