A company has a MongoDB replica set running on-premises accessible over AWS Direct Connect. A solutions architect must migrate the on-premises MongoDB database to Amazon DocumentDB (with MongoDB compatibility). Which migration approach should the architect use?

AWS DMS is the most suitable service for migrating on-premises databases to AWS, including MongoDB to Amazon DocumentDB. It supports heterogeneous migrations and continuous replication using Change Data Capture (CDC), ensuring minimal downtime. The process involves setting up a DMS replication instance, defining source (on-premises MongoDB) and target (Amazon DocumentDB) endpoints, and then creating and running a migration task. Launching EC2 instances with MongoDB Community Edition is a manual approach that doesn't leverage DocumentDB's benefits and requires significant operational overhead for replication. AWS Data Pipeline is primarily for scheduled data movement and transformation, not real-time or continuous database migrations with CDC. AWS Glue crawlers are used for cataloging data in data lakes and data warehouses, not for direct database migration or replication between transactional databases.