AWS Certified SysOps Administrator – Associate (legacy) — Question 918

An ecommerce company uses an Amazon ElastiCache for Memcached cluster for in-memory caching of popular product queries on the shopping site. When viewing recent Amazon CloudWatch metrics data for the ElastiCache cluster, the sysops administrator notices a large number of evictions.
Which of the following actions will reduce these evictions? (Choose two.)

Answer options

• A. Add an additional node to the ElastiCache cluster
• B. Increase the ElastiCache time to live (TTL)
• C. Increase the individual node size inside the ElastiCache cluster
• D. Put an Elastic Load Balancer in front of the ElastiCache cluster
• E. Use Amazon Simple Queue Service (Amazon SQS) to decouple the ElastiCache cluster

Correct answer: A, C

Explanation

Evictions occur in Amazon ElastiCache for Memcached when the cache memory is full and older data must be removed to make room for new writes. To mitigate this issue, the total memory capacity of the cluster must be increased, which can be done by either adding more nodes to the cluster (scaling out) or selecting a larger node type (scaling up). Increasing TTL would keep items in memory longer and worsen evictions, while load balancers and SQS do not add memory capacity to the cache.