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?
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
Answer: A
Explanation:
DynamoDB is automatically available across three facilities in an AWS Region. So moving in to a same AZ is not possible /necessary. In this case the DB layer is not the issue, the EC2 8xlarge is the issue; so add another one with a ELB in-front of it. See also: https://aws.amazon.com/dynamodb/faqs/