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Difficulty: Very hardSelecting and Designing Storage and Database Resources

A global media enterprise is designing the cloud storage and database architecture on Google Cloud for a mission-critical application platform. The architecture must address two key technical requirements:

1. An operational relational database that requires strong consistency (ACID compliance) across multiple geographic regions, along with horizontal scaling for write operations.
2. A one-time bulk migration of a 3 PB3\text{ PB} historical analytics dataset stored on local network-attached storage (NAS) devices, where the available dedicated internet bandwidth is capped at 100 Mbps100\text{ Mbps}.

Which TWO design decisions should the architect select to fulfill these requirements?

  1. Deploy Cloud Spanner as the operational database solution to support multi-region horizontal write scaling while maintaining strong ACID consistency.Answer
  2. B
    Deploy Cloud SQL for PostgreSQL with cross-region read replicas to achieve multi-region write scaling and relational transactional consistency.
  3. Order Google Cloud Transfer Appliance devices to physically capture and ingest the 3 PB dataset into Cloud Storage.Answer
  4. D
    Utilize Storage Transfer Service to stream the 3 PB dataset online over the 100 Mbps connection directly into a Cloud Storage bucket.

Answer

The optimal solution requires selecting Cloud Spanner for the globally scalable relational database and using GCP Transfer Appliance for the 3 PB offline bulk data migration.
Cloud Spanner is designed specifically for enterprise relational database workloads that require multi-region horizontal scaling for both reads and writes while preserving strict ACID transactional consistency. For the data migration requirement, transferring 3 PB3\text{ PB} over a 100 Mbps100\text{ Mbps} network link is mathematically unviable, taking over seven years. Google Cloud Transfer Appliance provides dedicated hardware for offline data ingestion, allowing petabyte-scale data to be physically transported to GCP securely and efficiently.

Step-by-Step Solution

1
Evaluate operational relational database requirements against GCP database products.
Cloud Spanner satisfies global multi-region horizontal write scaling and strong ACID consistency, whereas Cloud SQL is limited to vertical scaling for writes and a single primary region.
Cloud Spanner uses TrueTime and distributed transactions to allow multi-region relational write scale.
2
Calculate data transfer time for 3 PB over a 100 Mbps network connection.
Transfer time exceeds 7.5 years (t=3×1015 bytes×8 bits/byte100×106 bits/sec≈2.4×108 secondst = \frac{3 \times 10^{15} \text{ bytes} \times 8 \text{ bits/byte}}{100 \times 10^6 \text{ bits/sec}} \approx 2.4 \times 10^8 \text{ seconds}).
Online migration via Storage Transfer Service is unfeasible within reasonable operational timelines.
3
Select the appropriate offline data transfer mechanism.
GCP Transfer Appliance allows shipping physical storage hardware to securely ingest petabyte-scale data into Cloud Storage.
Offline appliances bypass low-bandwidth WAN connections for massive datasets.

Key Concept

Selecting GCP Database and Storage Migration Services Based on Scale, Latency, and Network Throughput Constraints
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Topics

Selecting and Designing Storage and Database Resources