AZ-305 Question 196
Select 2A financial services company wants to migrate its mission-critical on-premises SQL Server databases to an Azure SQL Managed Instance while minimizing downtime. They have decided to use Azure Migrate and the Azure Database Migration Service to accomplish this. Which two actions should you recommend to ensure a minimal-downtime migration process?
- A
Use the online migration feature in Azure Database Migration Service to replicate transactions from the on-premises SQL Server to the Managed Instance in near-real time before the cutover.
- B
Export the database to a BACPAC file, then import the BACPAC file directly to the Managed Instance during a single offline window without transaction replication.
- C
Implement an offline migration strategy where you shut down the on-premises database before copying data to Azure, providing time for thorough testing during downtime.
- D
Leverage transaction replication if the source SQL Server supports it, using Azure Database Migration Service to synchronize changes until final cutover.
Show answer and explanation
Correct answers: A, D
Explanation
To minimize downtime in large-scale SQL Server migrations to Azure SQL Managed Instance, organizations commonly use Azure Database Migration Service’s online (continuous) data replication features or transaction replication. These methods ensure the on-premises database remains operational while synchronizing changes. Additional details on this approach can be found in Microsoft’s official documentation on using the Azure Database Migration Service for minimal downtime migrations.
- A. Correct.
Correct. The online migration feature in Azure Database Migration Service allows for continuous replication of the on-premises SQL Server database to the Azure destination. This approach aligns with minimal downtime because changes are replicated in near-real time, and only a brief cutover window is needed.
- B. Incorrect.
Incorrect. While exporting to a BACPAC file is a valid way to move a database, it usually requires significant downtime (especially for large databases) as transactions aren’t continuously replicated. This does not meet the requirement for minimal downtime.
- C. Incorrect.
Incorrect. An offline migration strategy involves taking the database offline for the entire duration of data transfer, which is not optimal for a mission-critical system that requires minimal downtime.
- D. Correct.
Correct. Transaction replication can be configured if the source SQL Server version and environment support it. Coupled with Azure Database Migration Service, it can keep the on-premises and Azure environments in sync until you decide on the final cutover, reducing application downtime.