Data Transmission Service:Migrate Amazon RDS for SQL Server to Alibaba Cloud

Considerations

• Full data migration increases load on both source and destination databases, which may degrade performance or cause unavailability—especially with low-spec instances, slow SQL queries, missing primary keys, or deadlocks. Evaluate database performance first and migrate during off-peak hours (CPU utilization below 30%).

• Incremental data migration is not supported because Amazon RDS for SQL Server does not provide the required sysadmin role permissions.

• If a source table lacks a primary key or unique constraint, duplicate data may occur in the destination.

• If a source database name does not conform to ApsaraDB RDS naming conventions, create the database in the destination instance before configuring the migration task.

  Note

  Database naming conventions and creation steps: Create accounts and databases.

• To perform incremental data migration, you must disable triggers and foreign keys in the destination database. Otherwise, the data migration task fails.

• DTS automatically resumes failed tasks. Stop or release the task before switching workloads to the destination instance to prevent data overwrites.

Migration types

• Schema migration

  DTS migrates the following object schemas to the destination instance: tables, views, triggers, synonyms, SQL stored procedures, SQL functions, plan guides, user-defined types, rules, defaults, and sequences.

• Full data migration

  DTS migrates all data of selected objects from the source to the destination instance.

  Note

  DTS does not migrate sql_variant data.

Billing

Database account permissions

To create database accounts and grant permissions:

• Amazon RDS for SQL Server: CREATE USER.

• ApsaraDB RDS for SQL Server: Create an account for an RDS SQL Server instance.

Full data migration

DTS migrates schemas and data in the following order to resolve object dependencies:

1. Schema migration for tables, views, synonyms, user-defined types, rules, defaults, and plan guides

2. Full data migration

3. Schema migration for SQL stored procedures, SQL functions, triggers, and foreign keys

Before you begin

1. Log in to the Amazon RDS for SQL Server Management Console.

2. Go to the Basic Information page of the Amazon RDS for SQL Server instance.

3. In the Security group rules section, click the name of the security group.

   

4. On the Security Groups page, add the CIDR blocks of DTS servers to an inbound rule. Whitelist DTS server IP addresses.

   Click the Inbound tab and click Edit. Set Type to custom TCP rule, Port Range to 1433, and Source to Custom. Enter the DTS server CIDR blocks and click Save.

   Note

   • Add only the CIDR blocks of DTS servers in the destination database region. For example, if the destination is in China (Hangzhou), add only the China (Hangzhou) CIDR blocks.

   • You can add all required CIDR blocks to a single inbound rule.

Procedure (new console)

1. Navigate to the migration task list page for the destination region using one of the following methods.

   From the DTS console

   1. Log on to the Data Transmission Service (DTS) console.

   2. In the navigation pane on the left, click Data Migration.

   3. In the upper-left corner of the page, select the region where the migration instance is located.

   From the DMS console

   Note

   The actual operations may vary based on the mode and layout of the DMS console. For more information, see Simple mode console and Customize the layout and style of the DMS console.

   1. Log on to the Data Management (DMS) console.

   2. In the top menu bar, choose Data + AI > Data Transmission (DTS) > Data Migration.

   3. To the right of Data Migration Tasks, select the region where the migration instance is located.

2. Click Create Task to navigate to the task configuration page.

3. Configure the source and destination databases.

   Warning

   After you select the source and destination instances, we recommend that you carefully read the limits displayed at the top of the page. Otherwise, the task may fail or data inconsistency may occur.

   Category	Parameter	Description
   N/A	Task Name	DTS automatically generates a task name. We recommend that you specify a descriptive name for easy identification. The name does not need to be unique.
   Source Database	Select Existing Connection	To use a database instance that has been added to the system (created or saved), select the desired database instance from the drop-down list. The database information below will be automatically configured. Note In the DMS console, this parameter is named Select a DMS database instance.. If you have not registered the database instance with the system, or do not need to use a registered instance, manually configure the database information below.
   	Database Type	Select SQL Server.
   	Connection Type	Select Public IP Address.
   	Instance Region	Select the region of the Amazon RDS for SQL Server instance. Note If the exact region is unavailable, select the closest region.
   	Domain Name or IP	Enter the endpoint of the Amazon RDS for SQL Server instance. Note The endpoint is on the Basic Information page of the instance.
   	Port Number	Enter the service port. Default: 1433.
   	Database Account	Enter the database account of the source instance. Required permissions for database accounts.
   	Database Password	Enter the password for the database account.
   Destination Database	Select Existing Connection	To use a database instance that has been added to the system (created or saved), select the desired database instance from the drop-down list. The database information below will be automatically configured. Note In the DMS console, this parameter is named Select a DMS database instance.. If you have not registered the database instance with the system, or do not need to use a registered instance, manually configure the database information below.
   	Database Type	Select SQL Server.
   	Connection Type	Select Alibaba Cloud Instance.
   	Instance Region	Select the region of the destination ApsaraDB RDS for SQL Server instance.
   	Instance ID	Select the destination ApsaraDB RDS for SQL Server instance.
   	Database Account	Enter the database account of the destination instance. Required permissions for database accounts.
   	Database Password	Enter the password for the database account.

4. After you complete the configuration, click Test Connectivity and Proceed at the bottom of the page. In the CIDR Blocks of DTS Servers dialog box that appears, click Test Connectivity.

   Note

   Ensure that the IP address segments of the DTS service are automatically or manually added to the security settings of the source and destination databases to allow access from DTS servers. For more information, see Add DTS server IP addresses to a whitelist.

5. Configure the task objects.

   1. On the Configure Objects page, configure the objects that you want to migrate.

      Parameter	Description
      Migration Types	Select both Schema Migration and Full Data Migration. Note Amazon RDS for SQL Server does not provide the sysadmin role permissions required for incremental data migration. Therefore, Incremental Data Migration is not supported. To ensure data consistency, do not write new data to the Amazon RDS for SQL Server instance during data migration.
      Processing Mode of Conflicting Tables	Precheck and Report Errors: Checks whether tables with the same names exist in the destination database. If no tables with the same names exist, the precheck is passed. If tables with the same names exist, an error is reported during the precheck, and the data migration task does not start. Note If a table in the destination database has the same name but cannot be easily deleted or renamed, you can change the name of the table in the destination database. For more information, see Object name mapping. Ignore Errors and Proceed: Skips the check for tables with the same names. Warning Selecting Ignore Errors and Proceed may cause data inconsistency and business risks. For example: If the table schemas are consistent and a record in the destination database has the same primary key value as a record in the source database: During full migration, DTS keeps the record in the destination database. The record from the source database is not migrated. During incremental migration, DTS does not keep the record in the destination database. The record from the source database overwrites the record in the destination database. If the table schemas are inconsistent, only some columns of data may be migrated, or the migration may fail. Proceed with caution.
      Source Objects	Select one or more objects from the Source Objects section. Click the icon and add the objects to the Selected Objects section. Note The granularity for selecting migration objects is schema, table, and column. If you select only tables or columns as migration objects, other objects such as views, triggers, and stored procedures are not migrated to the destination database.
      Selected Objects	To change the name of a single migration object in the target instance, right-click the object in the Selected Objects box. For more information, see Map individual schema, table, and column names. To change the names of multiple migration objects in the target instance, click Selected Objects in the upper-right corner of the Batch Edit box. For more information, see Map multiple schema, table, and column names. Note Object name mapping may cause dependent objects to fail migration.

   2. Click Next: Advanced Settings to configure advanced parameters.

      Parameter	Description
      Dedicated Cluster for Task Scheduling	By default, DTS schedules tasks on a shared cluster. You do not need to select one. If you want more stable tasks, you can purchase a dedicated cluster to run DTS migration tasks.
      Retry Time for Failed Connections	After the migration task starts, if the connection to the source or destination database fails, DTS reports an error and immediately begins to retry the connection. The default retry duration is 720 minutes. You can customize the retry time to a value from 10 to 1440 minutes. We recommend that you set the duration to more than 30 minutes. If DTS reconnects to the source and destination databases within the specified duration, the migration task automatically resumes. Otherwise, the task fails. Note For multiple DTS instances that share the same source or destination, the network retry time is determined by the setting of the last created task. Because you are charged for the task during the connection retry period, we recommend that you customize the retry time based on your business needs, or release the DTS instance as soon as possible after the source and destination database instances are released.
      Retry Time for Other Issues	After the migration task starts, if a non-connectivity issue, such as a DDL or DML execution exception, occurs in the source or destination database, DTS reports an error and immediately begins to retry the operation. The default retry duration is 10 minutes. You can customize the retry time to a value from 1 to 1440 minutes. We recommend that you set the duration to more than 10 minutes. If the related operations succeed within the specified retry duration, the migration task automatically resumes. Otherwise, the task fails. Important The value of Retry Time for Other Issues must be less than the value of Retry Time for Failed Connections.
      Enable Throttling for Full Data Migration	During full migration, DTS consumes read and write resources on the source and destination databases, which may increase the database load. If required, you can enable throttling for the full migration task. You can set Queries per second (QPS) to the source database, RPS of Full Data Migration, and Data migration speed for full migration (MB/s) to reduce the load on the destination database. Note This configuration item is available only if you select Full Data Migration for Migration Types. You can also adjust the full migration speed after the migration instance is running.
      Environment Tag	Optional. Select an environment tag to identify the instance.
      Configure ETL	Choose whether to enable the extract, transform, and load (ETL) feature. For more information, see What is ETL? Valid values: Yes: Enables the ETL feature. Enter data processing statements in the code editor. For more information, see Configure ETL in a data migration or data synchronization task. No: Disables the ETL feature.
      Monitoring and Alerting	Select whether to set alerts and receive alert notifications based on your business needs. No: Does not set an alert. Yes: Configure alerts by setting an alert threshold and an alert notifications. If a migration fails or the latency exceeds the threshold, the system sends an alert notification.

   3. Click Next: Data Validation to configure a data validation task.

      For more information about the data validation feature, see Configure data validation.

6. Save the task and run a precheck.

   • To view the parameters for configuring this instance when you call the API operation, move the pointer over the Next: Save Task Settings and Precheck button and click Preview OpenAPI parameters in the bubble that appears.

   • If you do not need to view or have finished viewing the API parameters, click Next: Save Task Settings and Precheck at the bottom of the page.

   Note

   • Before the migration task starts, DTS performs a precheck. The task starts only after it passes the precheck.

   • If the precheck fails, click View Details next to the failed check item, fix the issue based on the prompt, and then run the precheck again.

   • If a warning is reported during the precheck:

     • For check items that cannot be ignored, click View Details next to the failed item, fix the issue based on the prompt, and then run the precheck again.

     • For check items that can be ignored, you can click Confirm Alert Details, Ignore, OK, and Precheck Again to skip the alert item and run the precheck again. If you choose to ignore a warning, it may cause issues such as data inconsistency and pose risks to your business.

7. Purchase an instance.

   1. When the Success Rate is 100%, click Next: Purchase Instance.

   2. On the Purchase page, select the link specification for the data migration instance. For more information, see the following table.

      Category	Parameter	Description
      New Instance Class	Resource Group Settings	Select the resource group to which the instance belongs. The default value is default resource group. For more information, see What is Resource Management?
      	Instance Class	DTS provides migration specifications with different performance levels. The link specification affects the migration speed. You can select a specification based on your business scenario. For more information, see Data migration link specifications.

   3. After the configuration is complete, read and select Data Transmission Service (Pay-as-you-go) Service Terms.

   4. Click Buy and Start. In the OK dialog box that appears, click OK.

      You can view the progress of the migration task on the Data Migration Tasks list page.

      Note

      • If the migration task does not include incremental migration, it stops automatically after the full migration is complete. After the task stops, its Status changes to Completed.

      • If the migration task includes incremental migration, it does not stop automatically. The incremental migration task continues to run. While the incremental migration task is running, the Status of the task is Running.

Procedure (legacy console)

1. Log on to the DTS console.

   Note

   If you are automatically redirected to the Data Management (DMS) console, you can click the icon in the lower-right corner and then click to return to the classic DTS console.

2. In the left-side navigation pane, click Data Migration.

3. At the top of the Migration Tasks page, select the region of the destination cluster.

4. In the upper-right corner of the page, click Create Data Migration Task.

5. Configure the source and destination databases.

   Section	Parameter	Description
   N/A	Task Name	DTS auto-generates a task name. Use a descriptive name for easy identification. The name does not need to be unique.
   Source Database Information	Instance Type	Select self-managed database with a public IP address.
   	Instance Region	Not required when Instance Type is set to Instance Region.
   	Database Type	Select SQL Server.
   	Hostname or IP Address	Enter the endpoint of the Amazon RDS for SQL Server instance. Note The connection information is on the Basic Information page of the instance. On the Amazon RDS console, find the endpoint in the Connectivity & security section.
   	Port	Enter the service port. Default: 1433.
   	Database Account	Enter the source database account. Database account permissions.
   	Database Password	Enter the password for the database account. Note After you enter the source database information, you can click Test Connectivity next to Database Password to verify that the information is correct. If the information is correct, the message Passed is displayed. If the message Failed is displayed, click Diagnose next to the Failed message and adjust the source database information based on the prompts.
   Destination Database Information	Instance Type	Select RDS Instance.
   	Instance Region	Select the region of the destination instance.
   	RDS Instance ID	Select the ID of the ApsaraDB RDS for SQL Server instance.
   	Database Account	Enter the destination database account. Database account permissions.
   	Database Password	Enter the password for the database account. Note After you enter the destination database information, you can click Test Connectivity after Database Password to verify that the entered information is correct. If the information is correct, a Passed message is displayed. If a Failed message is displayed, click Diagnose after Failed and adjust the destination database information based on the prompts.

6. After you complete the configuration, click Set Allowlist and Next in the lower-right corner of the page.

   If the source or destination database is an Alibaba Cloud database instance, such as an ApsaraDB RDS for MySQL or ApsaraDB for MongoDB instance, DTS automatically adds the CIDR blocks of the DTS servers in the corresponding region to the instance's allowlist. If the source or destination database is a self-managed database on an Elastic Compute Service (ECS) instance, DTS automatically adds the CIDR blocks of the DTS servers in the corresponding region to the ECS instance's security group rules. You must also ensure that the self-managed database does not block access from the ECS instance. If the database is deployed in a cluster across multiple ECS instances, you must manually add the CIDR blocks of the DTS servers in the corresponding region to the security group rules of each remaining ECS instance. If the source or destination database is a self-managed database in a data center or from another cloud provider, you must manually add the CIDR blocks of the DTS servers in the corresponding region to allow access from the DTS servers. For a list of the CIDR blocks of DTS servers, see CIDR blocks of DTS servers.

   Warning

   Adding public IP addresses of DTS servers may introduce security risks. By using this product, you acknowledge and accept these risks. Implement basic security measures such as strong passwords, restricted ports, API authentication, regular network segment reviews, or private connections through Express Connect, VPN Gateway, or Smart Access Gateway.

7. Select the migration types and migration objects.

   Parameter	Description
   Migration Types	Select both Schema Migration and full data migration. Note Amazon RDS for SQL Server does not support incremental data migration because it does not grant the required sysadmin role permissions. To ensure data consistency, do not write new data to the Amazon RDS for SQL Server instance during the migration.
   Migration Objects	In the Available box, select the objects to migrate, and then click to move them to the Selected Objects box. Note Select objects at the database, table, or column level. By default, object names remain unchanged. To rename objects in the destination, use Object name mapping. If you use the object name mapping feature, dependent objects may fail migration.
   Object Name Mapping	Rename migration objects in the destination instance. Object name mapping.
   Retry duration for a failed connection to the source or destination database	Default retry duration: 12 hours. Customize as needed. If DTS reconnects within the specified duration, the task resumes automatically. Otherwise, the task fails. Note DTS charges for task running time during retry. Set the retry duration based on your needs, or release the DTS instance when the source and destination instances are released.

8. After you complete the configuration, click Precheck and Start in the lower-right corner of the page.

   Note

   • Before the migration task starts, DTS runs a precheck. The task can start only after it passes the precheck.

   • If the precheck fails, click the icon next to the failed item to view details.

     • Fix the issues as prompted and run the precheck again.

     • If you do not need to fix the warning items, you can select Ignore and then click Ignore Warnings and Rerun Precheck to run the precheck again.

9. After the task passes the precheck, click Next.

10. In the Confirm Settings dialog box that appears, select a Instance Class and select the Data Transmission Service (pay-as-you-go) Service Terms checkbox.

11. Click Buy and Start to start the data migration task.
    Note We recommend that you do not manually stop the task during full data migration. Otherwise, the data migrated to the destination database will be incomplete. You can wait until the data migration task automatically stops.

    

12. Switch your workloads to the destination ApsaraDB RDS for SQL Server instance.