AWS Certified SysOps Administrator – Associate (legacy) — Question 50

You have a web-style application with a stateless but CPU and memory-intensive web tier running on a cc2 8xlarge EC2 instance inside of a VPC The instance when under load is having problems returning requests within the SLA as defined by your business The application maintains its state in a DynamoDB table, but the data tier is properly provisioned and responses are consistently fast.
How can you best resolve the issue of the application responses not meeting your SLA?

Answer options

• A. Add another cc2 8xlarge application instance, and put both behind an Elastic Load Balancer
• B. Move the cc2 8xlarge to the same Availability Zone as the DynamoDB table
• C. Cache the database responses in ElastiCache for more rapid access
• D. Move the database from DynamoDB to RDS MySQL in scale-out read-replica configuration

Correct answer: A

Explanation

The correct answer is A because adding another cc2 8xlarge instance and placing them behind an Elastic Load Balancer allows for load distribution, enhancing the overall application response times. Option B is incorrect as moving the instance to the same Availability Zone as DynamoDB wouldn't necessarily improve response times since the bottleneck is in the web tier. Option C, while helpful for performance, does not directly address the load issue on the CPU and memory of the application tier. Option D is also incorrect, as switching to RDS MySQL may introduce additional latency and complexity without addressing the immediate resource constraints.