The best solution is to use Amazon RDS Proxy to create a proxy for the database and modify the Lambda function to use the RDS Proxy endpoint instead of the database endpoint. RDS Proxy acts as an intermediary between the application and the database, pooling and reusing connections to reduce the load on the Aurora instance. It is particularly effective in serverless environments like Lambda, which can rapidly scale and open many database connections in a short time. By reusing and managing connections efficiently, RDS Proxy prevents the database from being overwhelmed, mitigating timeout issues.

Heres why the other options are not suitable:

Configuring provisioned concurrency for the Lambda function improves cold-start performance but does nothing to reduce the number of database connections or ease the pressure on the Aurora instance. Making the database global also doesnt help this issue and involves unnecessary complexity and cost for this use case.

Creating a read replica in another Region and routing traffic using query string parameters is not a viable approach for write operations like order processing. Aurora read replicas are read-only, and this solution doesn't address the core issue of write connection saturation.

Migrating to DynamoDB using AWS DMS and rewriting the Lambda logic introduces significant changes to both the data layer and application logic. This goes against the requirement to make the fewest possible changes. While DynamoDB is excellent for high-traffic workloads, the migration effort is non-trivial and inappropriate for an immediate fix.

Why this question matters: This scenario reflects a real-world problemscaling serverless applications under sudden load while managing database bottlenecks. It tests your knowledge of how AWS services like RDS Proxy can optimize connection management and improve database resilience in serverless architectures.

Exam tip: When dealing with Lambda and database connection issues under high concurrency, look for RDS Proxy as a solution. It's often the best answer when the question emphasizes minimal code changes and performance optimization.

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