Answer: Use Amazon ElastiCache in front of the database.

## Explanation **Correct Answer: A - Use Amazon ElastiCache in front of the database.** **Why this is the correct answer:** 1. **Problem Statement**: The issue is specifically with **database read performance**. Users experience long delays and interruptions due to read operations on the RDS MySQL database. 2. **Amazon ElastiCache Solution**: - ElastiCache is a fully managed in-memory caching service that can significantly improve read performance - It can cache frequently accessed data (like gaming scores) in memory, reducing the load on the RDS database - This directly addresses the **read performance** issue mentioned in the problem - Requires minimal architectural changes - just adding a caching layer 3. **Why other options are incorrect:** - **Option B (RDS Proxy)**: RDS Proxy helps with connection pooling and failover, but doesn't directly improve read performance. It's more for managing database connections efficiently. - **Option C (Migrate to Lambda)**: While Lambda can scale automatically, migrating the entire application would require significant architectural changes, which contradicts the requirement to "minimize changes to the application's architecture." - **Option D (Migrate to DynamoDB)**: Migrating from a relational database (MySQL) to a NoSQL database (DynamoDB) would require major application changes, schema redesign, and potentially different query patterns. 4. **Key Benefits of ElastiCache:** - **Performance**: In-memory caching provides sub-millisecond latency for read operations - **Scalability**: Can handle increased read traffic without affecting the primary database - **Minimal Changes**: Can be implemented as a caching layer with relatively small application modifications - **Cost-effective**: Reduces the need to scale up the RDS instance for read performance **Best Practice**: For read-heavy applications like gaming score displays, implementing a caching layer with Amazon ElastiCache (using Redis or Memcached) is a standard AWS best practice to improve performance while maintaining the existing architecture.

Author: LeetQuiz Editorial Team