How to migrate a large-scale SQL Server database over low bandwidth using AWS Application Migration Service

Migrating a large-scale SQL Server database over low bandwidth can be a challenging and time-consuming task. However, with the help of AWS Application Migration Service (AWS MGN), you can simplify and accelerate the process of moving your database to the cloud. AWS MGN is a service that automates the replication and conversion of your on-premises SQL Server database to a fully managed Amazon Relational Database Service (Amazon RDS) instance or an Amazon Elastic Compute Cloud (Amazon EC2) instance. In this article, I will explain how AWS MGN works, what are the benefits and limitations of using it, and how to prepare, execute, and monitor your database migration using AWS MGN.

How AWS MGN works

AWS MGN uses a lightweight agent that you install on your source SQL Server database server. The agent captures the data changes on your database and sends them to a replication server in AWS. The replication server then applies the changes to a staging area in AWS, where your database is converted to the target platform of your choice. You can choose to migrate your database to Amazon RDS for SQL Server, which is a fully managed service that handles the maintenance, backup, and scaling of your database, or to Amazon EC2 for SQL Server, which gives you more control and flexibility over your database configuration and administration.

AWS MGN supports both full and incremental replication, which means you can replicate your entire database or only the changes that occur after the initial replication. You can also pause and resume the replication at any time, and perform multiple test migrations before the final cutover.

Benefits and limitations of using AWS MGN

Using AWS MGN for your SQL Server database migration has several benefits, such as:

• It reduces the downtime and risk of data loss during the migration, as you can keep your source database online and in sync with the target database until the cutover.
• It simplifies the conversion process, as you do not need to manually modify the schema, code, or configuration of your database to make it compatible with the target platform.
• It lowers the cost and complexity of the migration, as you do not need to provision or manage any intermediate servers or storage for the replication.
• It enables you to migrate your database over low bandwidth, as it compresses and encrypts the data before sending it to AWS.

However, there are also some limitations and prerequisites that you need to consider before using AWS MGN, such as:

• It only supports SQL Server versions 2008 R2 and later, and Windows Server versions 2008 R2 and later.
• It requires you to have administrator privileges on your source database server and an AWS account with sufficient permissions and resources.
• It may not support some features or functionalities of your source database, such as encrypted columns, FILESTREAM data, or SQL Server Agent jobs. You may need to migrate these manually or use other tools or methods.
• It may incur additional charges for the replication server, the staging area, and the data transfer. You can use the AWS MGN pricing calculator to estimate the cost of your migration.

How to prepare, execute, and monitor your database migration using AWS MGN

To migrate your SQL Server database using AWS MGN, you need to follow these steps:

• Create a replication server and a staging area in AWS using the AWS MGN console or the AWS Command Line Interface (AWS CLI).
• Download and install the AWS MGN agent on your source database server and register it with the replication server.
• Configure the replication settings, such as the target platform, the replication frequency, and the bandwidth limit.
• Start the replication and monitor the progress and status of your migration using the AWS MGN console or the AWS CLI.
• Perform a test migration and verify the functionality and performance of your target database in AWS.
• Stop the replication and perform the final cutover to switch your database traffic from the source to the target database.
• Clean up the replication server and the staging area in AWS and uninstall the AWS MGN agent from your source database server.

For more detailed instructions and best practices, you can refer to the AWS MGN documentation and the AWS MGN user guide.