AWS Certified Solutions Architect Professional SAP-C02 Practice Question

The correct answer is to migrate the database to Amazon Aurora PostgreSQL-Compatible Edition with an Aurora Serverless v2 writer instance. Amazon Aurora Serverless v2 is specifically designed for workloads with sudden and unpredictable changes in activity. It automatically and instantly scales compute and memory resources in fine-grained increments to match the application's load, without disrupting database connections. This addresses the core requirements of handling spiky traffic and minimizing costs by only paying for the capacity consumed. As a fully managed service compatible with PostgreSQL, it also eliminates the operational overhead of managing the database infrastructure while preserving the relational model.

Migrating to Amazon Aurora Provisioned is not the most optimal solution. While it reduces management overhead, the primary writer instance in a provisioned cluster has a fixed capacity. Scaling the writer requires manual intervention or a failover to a larger instance, which is not automatic and can incur downtime. This makes it less cost-effective for highly unpredictable workloads compared to Serverless v2.

Re-platforming to use Amazon DynamoDB would require a significant refactoring of the application, as it would mean moving from a relational (SQL) to a NoSQL data model. The scenario specifies a requirement to preserve the relational schema to minimize code changes, making this option unsuitable despite DynamoDB's excellent scaling capabilities.

Using an Amazon EC2 instance within an Auto Scaling group is not a recommended pattern for a primary stateful relational database. Managing state, data replication, and failover in such a configuration is extremely complex and error-prone, and it would not reduce the database administration burden. This pattern is better suited for stateless application tiers.