AWS Certified Database – Specialty — Question 332

A company wants to improve its ecommerce website on AWS. A database specialist decides to add Amazon ElastiCache for Redis in the implementation stack to ease the workload off the database and shorten the website response times. The database specialist must also ensure the ecommerce website is highly available within the company's AWS Region.
How should the database specialist deploy ElastiCache to meet this requirement?

Answer options

• A. Launch an ElastiCache for Redis cluster using the AWS CLI with the -cluster-enabled switch.
• B. Launch an ElastiCache for Redis cluster and select read replicas in different Availability Zones.
• C. Launch two ElastiCache for Redis clusters in two different Availability Zones. Configure Redis streams to replicate the cache from the primary cluster to another.
• D. Launch an ElastiCache cluster in the primary Availability Zone and restore the cluster's snapshot to a different Availability Zone during disaster recovery.

Correct answer: B

Explanation

To achieve high availability within an AWS Region, Amazon ElastiCache for Redis should be deployed in a Multi-AZ configuration with read replicas located in different Availability Zones, allowing for automatic failover if the primary node fails. Setting up two separate clusters with manual synchronization (Option C) or relying on snapshot restoration during a disaster (Option D) are inefficient and do not meet high availability standards. Simply enabling clustering via the CLI (Option A) configures data sharding but does not automatically set up the required Multi-AZ replication for high availability.