A global healthcare provider operates a critical patient record application on-premises. The application is a monolithic Java application with a PostgreSQL database. The provider wants to migrate this application to AWS to improve scalability and reliability, but they have a strict requirement that the application must remain highly available during the migration with minimal downtime. They also need to ensure data consistency between the on-premises and AWS environments throughout the migration. Which approach should the Solutions Architect recommend?
- AMigrate the PostgreSQL database to Amazon S3 as CSV files, then import the data into a new Amazon Aurora PostgreSQL-compatible database, and finally deploy the application on Amazon EC2.
- BRe-architect the monolithic application into microservices and deploy them on AWS Lambda and Amazon DynamoDB, then migrate the data using AWS DataSync.
- CUse AWS Database Migration Service (DMS) with Change Data Capture (CDC) to replicate the PostgreSQL database to Amazon RDS, then gradually redirect application traffic to a new Amazon EC2 deployment running the application.
- DPerform a 'lift and shift' migration of the entire application and database to Amazon EC2 and Amazon RDS for PostgreSQL during a scheduled maintenance window.
Show answer & explanationAnswer & explanation
Correct answer: C. Use AWS Database Migration Service (DMS) with Change Data Capture (CDC) to replicate the PostgreSQL database to Amazon RDS, then gradually redirect application traffic to a new Amazon EC2 deployment running the application.
AWS DMS with CDC allows for continuous replication of the database, ensuring data consistency while the application remains operational on-premises. Once the database is synchronized, application traffic can be gradually shifted to the AWS environment, minimizing downtime.
Why the other options are wrong
- A. Migrating to S3 as CSV and then importing would lead to significant downtime and potential data consistency issues during the migration, as it's not a continuous replication method.
- B. Re-architecting to microservices is a significant undertaking that goes beyond a migration strategy and would introduce considerable risk and complexity, not directly addressing the immediate migration need with minimal downtime.
- D. This approach would involve significant downtime during the migration, which contradicts the requirement for minimal downtime and high availability.
Database Migration Service (DMS) with CDC
AWS DMS is a cloud service that makes it easy to migrate relational databases, data warehouses, NoSQL databases, and other types of data stores. CDC (Change Data Capture) allows for continuous replication, keeping source and target databases synchronized.
- Supports homogeneous and heterogeneous database migrations.
- Enables continuous data replication with minimal downtime.
- Can be used for one-time migrations or ongoing replication.
Memory trick: DMS Delivers Seamless Data Shifts.