nerdexam
Amazon

DVA-C02 · Question #641

A developer is working on an ecommerce application that stores data in an Amazon RDS for MySQL cluster The developer needs to implement a caching layer for the application to retrieve information abou

The correct answer is B. Create an Amazon ElastiCache (Redis OSS) cluster. Update the application code to use the. Adding a caching layer in front of Amazon RDS for MySQL requires Amazon ElastiCache, which is the purpose-built AWS in-memory caching service compatible with relational databases.

Submitted by weili_xi· Mar 5, 2026Development with AWS Services

Question

A developer is working on an ecommerce application that stores data in an Amazon RDS for MySQL cluster The developer needs to implement a caching layer for the application to retrieve information about the most viewed products. Which solution will meet these requirements?

Options

  • AEdit the RDS for MySQL cluster by adding a cache node. Configure the cache endpoint instead of
  • BCreate an Amazon ElastiCache (Redis OSS) cluster. Update the application code to use the
  • CCreate an Amazon DynamoDB Accelerator (DAX) cluster in front of the RDS for MySQL cluster.
  • DConfigure the RDS for MySQL cluster to add a standby instance in a different Availability Zone.

How the community answered

(34 responses)
  • A
    3% (1)
  • B
    94% (32)
  • D
    3% (1)

Why each option

Adding a caching layer in front of Amazon RDS for MySQL requires Amazon ElastiCache, which is the purpose-built AWS in-memory caching service compatible with relational databases.

AEdit the RDS for MySQL cluster by adding a cache node. Configure the cache endpoint instead of

Amazon RDS does not support adding ElastiCache-style in-memory cache nodes directly; RDS has read replicas for read scaling but no built-in application-layer key-value cache that can be enabled as an option.

BCreate an Amazon ElastiCache (Redis OSS) cluster. Update the application code to use theCorrect

Amazon ElastiCache (Redis OSS) provides sub-millisecond in-memory caching; the application checks the cache before querying RDS, so popular product data is served from memory, drastically reducing database load and improving response times for high-read workloads like most-viewed product lookups.

CCreate an Amazon DynamoDB Accelerator (DAX) cluster in front of the RDS for MySQL cluster.

Amazon DynamoDB Accelerator (DAX) is an in-memory cache exclusively designed for DynamoDB and is not compatible with RDS for MySQL or any other relational database.

DConfigure the RDS for MySQL cluster to add a standby instance in a different Availability Zone.

A Multi-AZ standby instance provides high availability and automatic failover during outages but does not reduce read latency or offload query traffic, serving no caching purpose.

Concept tested: ElastiCache Redis as application-layer cache for Amazon RDS

Source: https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/WhatIs.html

Community Discussion

No community discussion yet for this question.

Sign up to join the discussion
Full DVA-C02 Practice