Question

Difficulty: MediumDesigning Migration Plans and Data Transfer Strategies

A healthcare startup plans to migrate its legacy on-premises architecture to Google Cloud. The environment consists of a 15 TB15\text{ TB} PostgreSQL transactional database and 25 TB25\text{ TB} of unstructured medical imaging files stored on an SMB file share. The company has a dedicated 1 Gbps1\text{ Gbps} network connection to GCP. The migration strategy must ensure minimal downtime for the database and direct online ingestion of the image files into Cloud Storage with automated integrity verification. Which TWO architectural solutions should be included in the migration design? (Select TWO.)

  1. Use Database Migration Service (DMS) with continuous CDC replication to migrate the PostgreSQL database to Cloud SQL.Answer
  2. Use Storage Transfer Service for on-premises data transfer to migrate the medical image files directly into Cloud Storage.Answer
  3. C
    Request a GCP Transfer Appliance to physically transport the 15 TB PostgreSQL database to avoid consuming bandwidth.
  4. D
    Migrate the PostgreSQL database directly to Cloud Spanner using standard pg_dump files to simplify transaction scaling.

Answer

The strategy should incorporate Database Migration Service (DMS) with continuous CDC for the PostgreSQL database and Storage Transfer Service for moving the file share data to Cloud Storage over the available network link.
The correct strategy combines Database Migration Service (DMS) for continuous CDC replication of the PostgreSQL database to Cloud SQL with Storage Transfer Service for streaming on-premises file share data to Cloud Storage. This design meets the requirements of minimal database downtime and online file migration over the 1 Gbps link.

Step-by-Step Solution

1
Evaluate database migration requirements for operational continuity.
Database Migration Service (DMS) provides continuous replication (CDC) from on-premises PostgreSQL to Cloud SQL, enabling minimal cutover downtime.
Offline methods or schema shifts to distributed databases like Cloud Spanner incur significant downtime or unnecessary architecture modifications.
2
Evaluate bandwidth limits for the 25 TB file transfer.
A 25 TB dataset over a 1 Gbps link takes approximately 55 to 60 hours at theoretical full saturation, which easily fits within online transfer windows using Storage Transfer Service.
Storage Transfer Service automates checksum verification and agent-based multi-threaded transfer over existing network lines without needing physical appliance logistics.

Key Concept

Selecting optimal online migration services (DMS and Storage Transfer Service) based on dataset scale, minimal downtime requirements, and network throughput.
Rate this question