AWS Certified Developer – Associate / Question #852 of 557

Question #852

A gaming company runs a real-time leaderboard application backed by an Amazon Aurora PostgreSQL database. The leaderboard data is updated continuously with complex player statistics and high-frequency interactions. The current architecture cannot serve read requests with low latency due to the rapidly changing data and high traffic volume. The company needs a solution to reduce read latency while ensuring data consistency.

Which solution will meet these requirements?

A

Use Amazon DynamoDB Accelerator (DAX) in front of the Aurora database to cache the frequently changing leaderboard data and reduce read latency.

B

Enable Amazon Aurora Global Database to replicate the leaderboard data across multiple AWS Regions and reduce latency for global users.

C

Deploy an Amazon CloudFront distribution configured to cache dynamic leaderboard data directly from the Aurora database at edge locations.

D

Implement an Amazon ElastiCache for Redis cluster. Modify the application to use a write-through caching strategy and retrieve data from Redis.

Explanation

Option D is correct because:
- ElastiCache for Redis provides an in-memory cache layer, enabling low-latency reads for high-frequency data.
- A write-through caching strategy ensures data consistency by updating the cache immediately after database writes, critical for real-time leaderboards.

Why other options are incorrect:
- A: DAX is only compatible with DynamoDB, not Aurora PostgreSQL.
- B: Aurora Global Database reduces cross-region latency but does not address read latency within the same region for rapidly changing data.
- C: CloudFront caches static content, not dynamic data like real-time leaderboards.

Key Points:
- Use in-memory caching (Redis) for low-latency reads.
- Write-through caching maintains consistency for rapidly changing data.
- Avoid solutions incompatible with the database type (DAX) or designed for static content (CloudFront).

Answer

The correct answer is: D