AWS Certified SysOps Administrator – Associate (legacy) — Question 656

A company is using an Amazon ElastiCache for Redis cluster in a production environment. To align with the company's technical requirements, a SysOps administrator needs to select a deployment to provide increased availability and fault tolerance.
Which action should the SysOps administrator take to accomplish this goal?

Answer options

• A. Deploy the ElastiCache cluster with Memcached as the engine.
• B. Deploy the Redis cluster within an Auto Scaling group to launch replicas across multiple Availability Zones.
• C. Verify that cluster mode is disabled. Increase the number of shards.
• D. Verify that Multi-AZ with automatic failover is enabled. Place replicas in multiple Availability Zones.

Correct answer: D

Explanation

To achieve high availability and fault tolerance in Amazon ElastiCache for Redis, Multi-AZ with automatic failover must be enabled, which automatically promotes a replica in another Availability Zone if the primary node fails. Distributing replica nodes across multiple Availability Zones protects the cluster against single-zone outages. Other options, like using Memcached or deploying ElastiCache within an Auto Scaling group, do not provide the native replication and failover features required for Redis high availability.