Implementing a Caching Solution with Cross-Region Read Replica Capability

Answer: C.

Option A is incorrect because cluster mode enabled does not offer cross-region replication.

Option B is incorrect because ElastiCache -automatic-failover-enabled flag is used for multi-AZ automatic failover.

It is not used for creating read-replicas.

Option C is CORRECT because the Global Datastore feature for ElastiCache can be used to create cross-region read replica clusters.

Option D is incorrect because DAX is a DynamoDB specific caching solution.

It also does not offer cross-region replication.

Reference:

https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Redis-Global-Datastore.html

The correct answer to this question is C. ElastiCache for Redis with Global Datastore feature.

Explanation: ElastiCache is a managed caching service provided by AWS. It supports two open-source in-memory caching engines: Redis and Memcached. Redis is a popular caching engine because of its high performance and advanced data structures. It supports replication, which enables creating read replicas in multiple regions.

To create a caching solution with cross-region read replica capability, we need to use the Global Datastore feature of ElastiCache for Redis. Global Datastore allows us to create a Redis cluster with read replicas in multiple regions. The read replicas can be used to serve read requests from local applications, which reduces latency and improves performance.

The key benefits of using ElastiCache for Redis with Global Datastore are:

• Cross-region replication: Global Datastore allows you to create read replicas in multiple regions. This enables you to serve read requests from local replicas, which reduces latency and improves performance.
• High availability: Global Datastore automatically promotes a replica to the primary node in case of a primary node failure. This ensures high availability and reduces downtime.
• Consistency: Global Datastore uses Redis replication to maintain consistency between the primary and replica nodes. This ensures that data is always up-to-date.

Option A is incorrect because ElastiCache for Redis with cluster mode enabled is used to create a sharded Redis cluster. This does not provide cross-region read replica capability.

Option B is incorrect because the --automatic-failover-enabled flag is used to enable automatic failover in a Redis cluster. This does not provide cross-region read replica capability.

Option D is incorrect because Amazon DAX (DynamoDB Accelerator) is a caching service for DynamoDB, not Redis. It does not provide cross-region read replica capability for Redis.