A company has a web application that uses Amazon API Gateway to route HTTPS requests to AWS Lambda functions. The application uses an Amazon Aurora MySQL database for its data storage. The…

Migrating to Amazon Aurora Serverless allows the database to automatically scale its capacity up and down based on application demand, including handling unpredictable surges in traffic and connection requests, preventing database overloads. It also manages connection pooling automatically, and restoring from a snapshot is a quick way to transition, making it a cost-effective and resilient solution.

Migrating from a relational Aurora MySQL database to a NoSQL Amazon DynamoDB table would involve significant schema redesign and application code changes for the Lambda functions, making it a complex and time-consuming solution, not "as quickly as possible" or "most cost-effectively" in terms of immediate implementation.

Creating an Amazon EventBridge rule to invoke a Lambda function to iterate through and kill idle connections is a reactive and complex operational task that does not inherently prevent connection surges or provide proactive scaling for the database, and is not a scalable solution for the core problem.

Increasing the instance class and `max_connections` for the existing Aurora database might temporarily alleviate some connection issues, but it's a fixed capacity solution that does not automatically scale with unpredictable surges and can lead to over-provisioning and higher costs during low traffic, making it less cost-effective than Serverless.