AWS Certified Developer – Associate (DVA-C02)Development with AWS ServicesMedium
A developer is building a high-performance web application that uses Amazon DynamoDB for its core data store. To improve read latency and reduce the load on the primary DynamoDB table, the developer wants to implement a caching layer that is fully managed and compatible with DynamoDB's API. Which AWS service should the developer choose?
- AAmazon ElastiCache for Redis
- BAmazon ElastiCache for Memcached
- CAmazon DynamoDB Accelerator (DAX)
- DAWS Lambda with a custom caching logic
Show answer & explanationAnswer & explanation
Correct answer: C. Amazon DynamoDB Accelerator (DAX)
Amazon DynamoDB Accelerator (DAX) is a fully managed, highly available, in-memory cache for DynamoDB that delivers up to a 10x performance improvement for read-heavy workloads. It is API-compatible with DynamoDB, requiring minimal application code changes.
Why the other options are wrong
- A. Amazon ElastiCache for Redis is a general-purpose in-memory data store, but it requires developers to manage caching logic and is not API-compatible with DynamoDB.
- B. Amazon ElastiCache for Memcached is another general-purpose caching service, similar to Redis, but also requires custom caching logic and is not API-compatible with DynamoDB.
- D. Implementing custom caching logic with AWS Lambda would introduce significant development overhead, maintenance, and potential performance bottlenecks compared to a managed service like DAX.
DynamoDB Accelerator (DAX)
A fully managed, highly available, in-memory cache for Amazon DynamoDB that delivers up to a 10x performance improvement for read-heavy workloads.
- API-compatible with DynamoDB, minimizing application code changes.
- Reduces read latency from milliseconds to microseconds.
- Automatically handles caching logic (e.g., item cache, query cache).
Memory trick: For 'DynamoDB' reads, 'DAX' is the 'accelerator' to make them faster.