Which solution will meet these requirements?
Migrate to a new Aurora multi-master DB cluster. Modify the application database connection string.
Modify the DB cluster by changing to serverless mode whenever user connections exceed 200.
Create an auto scaling policy with a target metric of 195 DatabaseConnections.
Modify the DB cluster by increasing the Aurora Replica instance size.
Explanations:
Aurora multi-master DB clusters are designed for high availability and write scalability, but they do not automatically scale read capacity based on connections.
Aurora serverless only works with Amazon Aurora MySQL-Compatible Edition in specific use cases. It also does not automatically scale based on connection count.
An auto-scaling policy with a target metric based on DatabaseConnections is ideal for dynamically adjusting capacity as user connections increase, improving performance.
Increasing the Aurora Replica instance size can help with read capacity, but this does not provide automatic scaling based on fluctuating user connections.
I arrange that the answer is:
Create an auto scaling policy with a target metric of 195 DatabaseConnections.