The correct answer is B. Create a replica database, synchronize the data, and switch to the new instance.
This option is the best option to perform the migration because it can minimize the downtime and data loss during the migration process. A replica database is a copy of the source database that is kept in sync with the changes made to the original database. By creating a replica database in the cloud, the cloud engineer can transfer the data incrementally and asynchronously, without affecting the availability and performance of the source database. When the replica database is fully synchronized with the source database, the cloud engineer can switch to the new instance by updating the connection settings and redirecting the traffic. This can reduce the downtime to a few minutes or seconds, depending on the complexity of the switch.
Some of the tools and services that can help create a replica database and synchronize the data are AWS Database Migration Service (AWS DMS) 1, Azure Database Migration Service 2, and Striim 3. These tools and services can support various source and target databases, such as Oracle, MySQL, PostgreSQL, SQL Server, MongoDB, etc. They can also provide features such as schema conversion, data validation, monitoring, and security.
The other options are not the best options to perform the migration because they can cause more downtime and data loss than the replica database option.
Copying the database to an external device and shipping the device to the CSP is a slow and risky option that can take days or weeks to complete. It also exposes the data to physical damage or theft during transit. Moreover, this option does not account for the changes made to the source database after copying it to the device, which can result in data inconsistency and loss.
Utilizing a third-party tool to back up and restore the data to the new database is a faster option than shipping a device, but it still requires a significant amount of downtime and bandwidth. The source database has to be offline or in read-only mode during the backup process, which can take hours or days depending on the size of the data and the network speed. The restore process also requires downtime and bandwidth, as well as compatibility checks and configuration adjustments. Additionally, this option does not account for the changes made to the source database after backing it up, which can result in data inconsistency and loss.
Using the database import/export method and copying the exported file is a similar option to using a third-party tool, but it relies on native database features rather than external tools. The import/export method involves exporting the data from the source database into a file format that can be imported into the target database. The file has to be copied over to the target database and then imported into it. This option also requires downtime and bandwidth during both export and import processes, as well as compatibility checks and configuration adjustments. Furthermore, this option does not account for the changes made to the source database after exporting it, which can result in data inconsistency and loss.
