Data Transmission Service:Migrate data between RDS instances of different Alibaba Cloud accounts

Prerequisites

The available storage space of the destination instance is larger than the total size of the data in the source instance.

Billing

Permissions required for database accounts

Before you begin

Log on to the Resource Access Management (RAM) console by using the Alibaba Cloud account that owns the source instance (Account A). Specify the Alibaba Cloud account that owns the destination instance (Account B) as a trusted account. Then, authorize Account B to access the cloud resources of Account A by using DTS. For more information, see Configure RAM authorization for cross-account data migration and synchronization.

Procedure

1. Log on to the DTS console by using the Alibaba Cloud account that owns the destination RDS instance.
2. In the left-side navigation pane, click Data Migration.
3. In the upper part of the Migration Tasks page, select the region in which the ApsaraDB RDS for MySQL instance resides.
4. In the upper-right corner of the page, click Create Migration Task.
5. In the Source Database section, set Instance Type to RDS Instance, and click RDS Instances of Other Apsara Stack Accounts next to the RDS Instance ID field.
6. Configure the source and destination databases.

   Parameter	Description
   Task Name	DTS automatically generates a task name. We recommend that you specify an informative name to identify the task. You do not need to specify a unique task name.
   Source Database	Instance Type: Select RDS Instance. Note If you have selected RDS Instance as the instance type, you can skip this step. Instance Region: Select the region where the source RDS instance resides. Note You can select different regions for the source and destination RDS instances. Apsara Stack Tenant Account ID of RDS Instance: Enter the ID of the Alibaba Cloud account that owns the source instance. Note To obtain the ID of the Alibaba Cloud account that owns the source instance, you must log on to the Account Management console by using this account. The account ID is displayed on the Security Settings page. Role Name: Enter the role name configured for the Alibaba Cloud account that owns the source instance. For more information, see Configure RAM authorization for cross-account data migration and synchronization. RDS Instance ID: Select the ID of the source RDS instance. Note If an alert message appears when you select an RDS instance ID, modify the parameter values as prompted. For more information, see FAQ. Database Account: Enter the database account of the source RDS instance. For information about the permissions that are required for the account, see Permissions required for database accounts. Database Password: Enter the password of the database account.
   Destination Database	Instance Type: Select RDS Instance. Note You can select different regions for the source and destination RDS instances. Instance Region: Select the region where the destination RDS instance resides. RDS instance ID: Select the ID of the destination RDS instance. Database Account: Enter the database account of the destination RDS instance. For information about the permissions that are required for the account, see Permissions required for database accounts. Database Password: Enter the password of the database account. Encryption: Select Non-encrypted or SSL-encrypted. In this example, select Non-encrypted. Note If you want to select SSL-encrypted, you must enable SSL encryption for the RDS instance before you configure the data migration task. For more information, see Configure SSL encryption for an ApsaraDB RDS for MySQL instance.

7. In the lower-right corner of the page, click Set Whitelist and Next.
   Warning If the CIDR blocks of DTS servers are automatically or manually added to the whitelist of the database or instance, or to the ECS security group rules, security risks may arise. Therefore, before you use DTS to migrate data, you must understand and acknowledge the potential risks and take preventive measures, including but not limited to the following measures: enhance the security of your username and password, limit the ports that are exposed, authenticate API calls, regularly check the whitelist or ECS security group rules and forbid unauthorized CIDR blocks, or connect the database to DTS by using Express Connect, VPN Gateway, or Smart Access Gateway.
8. Select the objects to be migrated and the migration types.

   Parameter or setting	Description
   Select the migration types	To perform only full data migration, select Schema Migration and Full Data Migration. To ensure service continuity during data migration, select Schema Migration, Full Data Migration, and Incremental Data Migration. Note If Incremental Data Migration is not selected, do not write data to the source database during data migration. This ensures data consistency between the source and destination databases.
   Select the objects to be migrated	Select one or more objects from the Available section and click the icon to add the objects to the Selected section. Note You can select columns, tables, or databases as the objects to be migrated. If you select tables or columns as the objects to be migrated, DTS does not migrate other objects such as views, triggers, or stored procedures to the destination database. By default, after an object is migrated to the destination database, the name of the object remains unchanged. You can use the object name mapping feature to rename the objects that are migrated to the destination database. For more information, see Object name mapping. If you use the object name mapping feature to rename an object, other objects that are dependent on the object may fail to be migrated.
   Specify whether to rename objects	You can use the object name mapping feature to rename the objects that are migrated to the destination instance. For more information, see Object name mapping.
   Specify the retry time range for failed connections to the source or destination database	By default, if DTS fails to connect to the source or destination database, DTS retries within the following 12 hours. You can specify the retry time range based on your business requirements. If DTS is reconnected to the source and destination databases within the specified time range, DTS resumes the data migration task. Otherwise, the data migration task fails. Note When DTS retries a connection, you are charged for the DTS instance. We recommend that you specify the retry time based on your business requirements. You can also release the DTS instance at your earliest opportunity after the source and destination instances are released.
   Specify whether to copy temporary tables to the destination database when DMS performs online DDL operations on the source table	If you use DMS to perform online DDL operations on the source database, you can specify whether to migrate temporary tables generated by online DDL operations. Yes: DTS migrates the data of temporary tables generated by online DDL operations. Note If online DDL operations generate a large amount of data, latency may occur for the data migration task. No: DTS does not migrate the data of temporary tables generated by online DDL operations. Only the original DDL data of the source database is migrated. Note If you select No, the tables in the destination database may be locked.

9. Click Precheck.
   Note

   • A precheck is performed before the migration task starts. The migration task only starts after the precheck succeeds.
   • If the precheck fails, click the icon next to each failed check item to view the related details. Fix the issues as instructed and run the precheck again.
10. After the task passes the precheck, click Next.
11. In the Confirm Settings dialog box, specify the Instance Class parameter and select the check box to agree to Data Transmission Service (Pay-As-You-Go) Service Terms.
12. Click Buy and Start to start the data migration task.
    • Full data migration

      Do not manually stop a full data migration task. If you manually stop a full data migration task, the data that is migrated to the ApsaraDB RDS for MySQL instance may be incomplete. You can wait until the data migration task automatically stops.

    • Incremental data migration

      An incremental data migration task does not automatically stop. You must manually stop the task.

      Note We recommend that you manually stop an incremental data migration task at an appropriate point in time. For example, you can stop the task during off-peak hours or before you switch your workloads over to the ApsaraDB RDS for MySQL instance.
      1. Wait until Incremental Data Migration and The data migration task is not delayed are displayed in the progress bar of the data migration task. Then, stop writing data to the source database for a few minutes. The latency of incremental data migration may be displayed in the progress bar.
      2. Wait until the status of incremental data migration changes to The data migration task is not delayed again. Then, manually stop the migration task.

FAQ

If an alert message appears when you set the RDS Instance ID parameter for the source database, you can solve the issue as described in following table.

Alert message	Solution
	Check whether the ID of the Alibaba Cloud account that owns the source instance and the role name configured for the account are valid. Note To obtain the ID of the Alibaba Cloud account that owns the source instance, you must log on to the Account Management console by using this account. The account ID is displayed on the Security Settings page.
	Make sure that you have performed the following steps: 1. Log on to the RAM console by using the Alibaba Cloud account that owns the source instance (Account A). 2. Specify the Alibaba Cloud account that owns the destination instance (Account B) as a trusted account. 3. Authorize Account B to access the cloud resources of Account A by using DTS. For more information, see Configure RAM authorization for cross-account data migration and synchronization.