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Difficulty: Very hardDesigning Migration Plans and Data Transfer Strategies

A financial analytics firm is planning to migrate its core infrastructure to Google Cloud. The workload includes 1.2 PB of historical unstructured market data stored on an on-premises SAN and an active 8 TB MySQL database supporting real-time trading analytics. The firm has a dedicated 1 Gbps network connection to Google Cloud via Dedicated Interconnect, with a maximum allocated bandwidth of 700 Mbps for migration traffic. Enterprise compliance requires complete transfer of historical data within 21 days, and the business allows a maximum database cutover downtime window of 4 hours. Which architecture and data transfer strategy successfully meets these operational and business constraints?

  1. Order a GCP Transfer Appliance to transfer the 1.2 PB historical market data offline to Cloud Storage, and utilize Database Migration Service (DMS) for Cloud SQL for MySQL to perform initial data loading and continuous change data capture (CDC) over Dedicated Interconnect prior to final cutover.Answer
  2. B
    Utilize Storage Transfer Service over the 700 Mbps Dedicated Interconnect link to stream the 1.2 PB historical market data directly to Cloud Storage, while using Database Migration Service with continuous CDC for the 8 TB MySQL database.
  3. C
    Order a GCP Transfer Appliance for the 1.2 PB historical market data transfer, and migrate the 8 TB MySQL database to Cloud Spanner using a full database export and import during the 4-hour maintenance window.
  4. D
    Establish an HA VPN tunnel over the public internet to transfer both the 1.2 PB market data and the 8 TB MySQL database replication streams concurrently to reduce infrastructure cost.

Answer

Order a GCP Transfer Appliance to perform an offline transfer of the 1.2 PB historical market data to Cloud Storage, and use Database Migration Service (DMS) with continuous Change Data Capture (CDC) over Dedicated Interconnect to migrate the 8 TB MySQL database to Cloud SQL for MySQL.
The correct strategy combines an offline Transfer Appliance for the 1.2 PB static historical dataset with Database Migration Service (DMS) over Dedicated Interconnect for the 8 TB MySQL database. The network calculation shows that transferring 1.2 PB over 700 Mbps would take over 150 days, making an offline appliance necessary to meet the 21-day timeline. Furthermore, continuous CDC via DMS keeps the destination database updated in real-time, allowing the final cutover to take place well within the 4-hour downtime window.

Step-by-Step Solution

1
Calculate network throughput feasibility for historical data transfer.
Streaming 1.2 PB (1.2×10151.2 \times 10^{15} bytes) over 700 Mbps (0.7 Gbps0.7 \text{ Gbps}) yields ≈7.56 TB/day\approx 7.56 \text{ TB/day}, taking over 158 days. Offline appliance transfer is mandatory to meet the 21-day window.
Online transfer cannot meet the time constraints of the SLA over the existing network bandwidth.
2
Evaluate database cutover downtime constraints.
Moving an 8 TB database within a 4-hour downtime window requires continuous replication (CDC) to keep the target cloud database synchronized prior to a swift DNS cutover.
Full offline dump and restore of 8 TB would exceed 4 hours of downtime.
3
Select appropriate target GCP database and migration service.
Use Cloud SQL for MySQL with Database Migration Service (DMS) using Dedicated Interconnect for secure, low-latency CDC replication streams.
Cloud SQL maintains native MySQL compatibility without requiring application refactoring for Spanner, while DMS handles continuous CDC seamlessly.

Key Concept

Designing hybrid data migration strategies balancing network bandwidth limitations, offline appliances, and database replication services.
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Topics

Designing Migration Plans and Data Transfer Strategies