Question

A web application allows customers to upload orders to an S3 bucket. The resulting Amazon S3 events trigger a Lambda function that inserts a message to an SQS queue. A single EC2 instance

reads messages from the queue, processes them, and stores them in an DynamoDB table partitioned by unique order ID. Next month traffic is expected to increase by a factor of 10 and a Solutions Architect is reviewing the architecture for possible scaling problems.

Which component is MOST likely to need re-architecting to be able to scale to accommodate the new traffic?

A. Lambda function

B. SQS queue

C. EC2 instance

D. DynamoDB table

Answer 1

C – A single EC2 instance will not scale and is a single point of failure in the architecture. A much better solution would be to have EC2 instances in an Auto Scaling group across 2 availability zones read messages from the queue. The other responses are all managed services that can be configured to scale or will scale automatically.