AWS Certified SysOps Administrator – Associate — Question 451

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 in Amazon ElastiCache for Memcached occur when the cache runs out of memory and must remove older data to accommodate new writes. To reduce these evictions, you can increase the total memory available by either adding more nodes to the cluster (scaling out) or selecting a larger node size (scaling up). Increasing the TTL would actually worsen evictions by holding onto data longer, while ELB and Amazon SQS do not increase cache memory capacity.