Reduce Memory and CPU Overhead: Optimal Solution for Serverless Application

Answer: B.

Option A is incorrect because this is not the optimal solution.

Increasing the database class can make more database resources available for connection management, but it does not reduce the memory and CPU overhead associated with connection management.

Option B is CORRECT because RDS proxy is a service that can be used to pool simultaneous connections from serverless applications and alleviate the connection management from the RDS database instance.

Option C is incorrect because AWS PrivateLink is a service that provides private VPC network integration for cloud-based services.

Option D is incorrect because the requirement is to reduce the overhead associated with connections to the RDS database.

Implementing ElastiCache would require a code change.

Also, the question does not specify that caching is appropriate or possible in this use case.

This is not an applicable option in this scenario.

Reference:

https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/rds-proxy.html

The optimal solution to reduce the memory and CPU overhead for connection management on the database, when a serverless application is being developed using AWS Lambda and Amazon RDS as a database, is to create an RDS Proxy.

RDS Proxy is a fully managed database proxy that allows applications to pool and share database connections, reducing the overhead of establishing new database connections. It provides efficient, secure, and scalable access to your Amazon RDS and Aurora databases, and helps to reduce database load and improve application scalability.

Option A - Upgrade the database to a larger database class: Upgrading the database to a larger class may help in improving performance, but it will not solve the issue of connection management overhead. In fact, it may lead to an increase in cost without actually solving the problem.

Option C - Create an AWS PrivateLink: AWS PrivateLink is a service that allows secure and private access to services over the AWS network. While it can help to secure the communication between Lambda and RDS, it doesn't address the connection management overhead.

Option D - Create an AWS ElastiCache cluster: ElastiCache is a managed in-memory caching service that can be used to speed up read-heavy workloads. It doesn't help to reduce the connection management overhead on the database and may not be suitable for write-heavy workloads.

In summary, the optimal solution to reduce the memory and CPU overhead for connection management on the database in a serverless application that uses AWS Lambda and Amazon RDS as a database is to create an RDS Proxy.