Google Cloud Professional Cloud Database Engineer — Question 159

Your company is migrating from an on-premises database to a single-region Spanner instance. The current database supports 40,000 reads each second, and 7,000 writes each second, at 1 KB row sizes at peak. You need to determine the most cost-effective size for the Spanner instance to handle the equivalent current workload. What should you do?

Answer options

• A. Select a 4-node Spanner instance.
• B. Select a 6-node Spanner instance.
• C. Select a 1-node Spanner instance.
• D. Recommend a multi-region Spanner instance.

Correct answer: A

Explanation

Selecting a 4-node Spanner instance is the correct choice as it provides the necessary capacity to handle the specified reads and writes efficiently. A 6-node instance would be more expensive without significantly increasing performance for this workload, while a 1-node instance would not meet the required throughput. A multi-region Spanner instance is not needed for a single-region workload and would incur additional costs.