You can use Data Transmission Service (DTS) to migrate data between ApsaraDB RDS instances of different Alibaba Cloud accounts. This topic describes how to use DTS to migrate data between ApsaraDB RDS instances of different Alibaba Cloud accounts.

Prerequisites

  • The account of the destination instance is an Alibaba Cloud account.
  • The available storage space of the destination instance is larger than the total size of the data in the source instance.

Billing

Migration type Task configuration fee Internet traffic fee
Schema migration and full data migration Free of charge. Charged only when data is migrated from Alibaba Cloud over the Internet. For more information, see Billing overview.
Incremental data migration Charged. For more information, see Billing overview.

Permissions required for database accounts

Instance Schema migration Full data migration Incremental data migration
Source ApsaraDB RDS instance Read and write permissions Read and write permissions Read and write permissions
Destination ApsaraDB RDS instance Read and write permissions Read and write permissions Read and write permissions

Preparations

  1. Optional:Obtain the IDs of the Alibaba Cloud accounts to which the source and destination instances belong.
    Note Skip the step if you have obtained the IDs of the Alibaba Cloud accounts to which the source and destination instances belong.
    1. Log on to the Account Management console by using the Alibaba Cloud account to which the source or destination instance belongs.
    2. Optional:In the left-side navigation pane, click Basic Information.
    3. View and record the value of the Account ID parameter.
  2. Create a RAM role.
    1. Log on to the RAM console by using the Alibaba Cloud account to which the source instance belongs.
    2. In the left-side navigation pane, choose Identities > Roles.
    3. On the Roles page, click Create Role.
    4. In the Create Role panel, select Alibaba Cloud Account for the Select Trusted Entity parameter and click Next.
    5. In the Configure Role step, set parameters for the RAM role.
      Parameter Description
      RAM Role Name The name of the RAM role. In this example, ram-for-dts is used.
      Note The role name must be 1 to 64 characters in length and can contain letters, digits, and hyphens (-).
      Note Optional. The description for the RAM role.
      Select Trusted Alibaba Cloud Account Select Other Alibaba Cloud Account and enter the ID of the Alibaba Cloud account to which the destination instance belongs. For information about how to obtain the ID of an Alibaba Cloud account, see Preparations.
    6. Click OK.
  3. Click Input and Attach to grant permissions to the created RAM role.
    1. In the Add Permissions panel, select System Policy as Type.
    2. In the Policy Name field, enter AliyunDTSRolePolicy.
    3. Click OK.
    4. After you grant the permissions, click Close.
  4. Modify the trust policy.
    1. On the Roles page, find the RAM role that you created and click the role name to view details.
    2. On the Basic Information page of the RAM role, click the Trust Policy Management tab.
    3. On the Trust Policy Management tab, click Edit Trust Policy.
    4. Copy the following code to the code editor:
      {
          "Statement": [
              {
                  "Action": "sts:AssumeRole",
                  "Effect": "Allow",
                  "Principal": {
                      "RAM": [
                          "acs:ram::<ID of the Alibaba Cloud account to which the destination instance belongs>:root"
                      ],
                      "Service": [
                          "<ID of the Alibaba Cloud account to which the destination instance belongs>@dts.aliyuncs.com"
                      ]
                  }
              }
          ],
          "Version": "1"
      }
      Note In the preceding code, replace ID of the Alibaba Cloud account to which the destination instance belongs with the Alibaba Cloud account ID that you specified when you configure the RAM role information.
    5. Click OK.

Procedure

  1. Log on to the Data Migration page of the new DTS console by using the Alibaba Cloud account that owns the destination instance.
    Note You can also log on to the Data Management (DMS) console. In the top navigation bar, click DTS. Then, in the left-side navigation pane, choose DTS (DTS) > Data Migration.
  2. In the upper-left corner of the page, select the region in which the data migration instance resides.
    Select a region
  3. Click Create Task and configure the source and destination instances.
    Warning After you select the source and destination instances, we recommend that you read the limits displayed at the top of the page. This helps you create and run the data migration task.
    Section Parameter Description
    N/A Task Name

    The name of the task. 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 Select Instance
    The instance that you want to use. You can choose whether to use an existing instance based on your business requirements.
    • If you use an existing instance, DTS automatically applies the parameter settings of the instance.
    • If you do not use an existing instance, you must set parameters for the source database.
    Database Type The type of the source database. Select MySQL.
    Access Method The access method of the source database. Select Alibaba Cloud Instance.
    Instance Region The region in which the source ApsaraDB RDS instance resides.
    Note You can select different regions for the source and destination ApsaraDB RDS instances.
    Replicate Data Across Alibaba Cloud Accounts Specifies whether data is replicated across Alibaba Cloud accounts. In this example, Yes is selected.
    Alibaba Cloud Account 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.
    RAM Role Name The RAM role that is assigned to 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 The ID of the source ApsaraDB RDS instance.
    Note If an alert message is displayed when you select an ApsaraDB RDS instance ID, modify the parameter values as prompted. For more information about alert messages, see the FAQ section of this topic.
    Database Account The account of the source database. For more information about the required permissions, see the Permissions required for database accounts section of this topic.
    Database Password

    The password of the database account.

    Encryption Specifies whether to encrypt the connection to the source database. Select Non-encrypted or SSL-encrypted based on your requirements. In this example, Non-encrypted is selected.
    Note If you want to select SSL-encrypted, you must enable SSL encryption for the ApsaraDB RDS instance before you configure the data migration task. For more information, see Configure SSL encryption on an ApsaraDB RDS for MySQL instance.
    Destination Database Select Instance
    The instance that you want to use. You can choose whether to use an existing instance based on your business requirements.
    • If you use an existing instance, DTS automatically applies the parameter settings of the instance.
    • If you do not use an existing instance, you must set parameters for the destination database.
    Database Type The type of the destination database. Select MySQL.
    Access Method The access method of the destination database. Select Alibaba Cloud Instance.
    Instance Region The region in which the destination ApsaraDB RDS instance resides.
    Note You can select different regions for the source and destination ApsaraDB RDS instances.
    RDS Instance ID The ID of the destination ApsaraDB RDS instance.
    Note If an alert message is displayed when you select an ApsaraDB RDS instance ID, modify the parameter values as prompted. For more information about alert messages, see the FAQ section of this topic.
    Database Account The account of the destination database. For more information about the required permissions, see the Permissions required for database accounts section of this topic.
    Database Password

    The password of the database account.

    Encryption Specifies whether to encrypt the connection to the destination database. Select Non-encrypted or SSL-encrypted based on your requirements. In this example, Non-encrypted is selected.
    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 on an ApsaraDB RDS for MySQL instance.
  4. In the lower part of the page, click Test Connectivity and Proceed.
    Warning
    • If the source or destination database instance is an Alibaba Cloud database instance, such as a ApsaraDB RDS for MySQL or ApsaraDB for MongoDB instance, or is a self-managed database hosted on Elastic Compute Service (ECS), DTS automatically adds the CIDR blocks of DTS servers to the whitelist of the database instance or ECS security group rules. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases. If the source or the destination database is a self-managed database on data centers or is from other cloud service providers, you must manually add the CIDR blocks of DTS servers to allow DTS to access the database.
    • If the CIDR blocks of DTS servers are automatically or manually added to the whitelist of the database, Alibaba Cloud database instance, or 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: enhancing the security of your username and password, limiting the ports that are exposed, authenticating API calls, regularly checking the whitelist or ECS security group rules and forbidding unauthorized CIDR blocks, or connecting the database to DTS by using Express Connect, VPN Gateway, or Smart Access Gateway.
    • After the DTS task is complete or released, we recommend that you manually detect and remove the added CIDR blocks from the whitelist or ECS security group rules.
  5. Select objects for the task and configure advanced settings.
    • Basic Settings
      Parameter Description
      Task Stages
      • 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, we recommend that you do not write data to the source instance during data migration. This ensures data consistency between the source and destination instances.
      Processing Mode of Conflicting Tables
      • Precheck and Report Errors: checks whether the destination database contains tables that have the same names as tables in the source database. If the source and destination databases do not contain tables that have the same names, the precheck is passed. Otherwise, an error is returned during the precheck and the data migration task cannot be started.

        Note You can use the object name mapping feature to rename the tables that are migrated to the destination database. You can use this feature if the source and destination databases contain tables that have identical names and the tables in the destination database cannot be deleted or renamed. For more information, see Map object names .
      • Ignore Errors and Proceed: skips the precheck for identical table names in the source and destination databases.
        Warning If you select Ignore Errors and Proceed, data consistency is not ensured, and your business may be exposed to potential risks.
        • If the source and destination databases have the same schema, DTS does not migrate data records that have the same primary keys as data records in the destination database.
        • If the source and destination databases have different schemas, only specific columns are migrated or the data migration task fails.
      Capitalization of Object Names in Destination Instance

      The capitalization of database names, table names, and column names in the destination instance. By default, DTS default policy is selected. You can select other options to ensure that the capitalization of object names is consistent with that in the source or destination database. For more information,see Specify the capitalization of object names in the destination instance.

      Select Objects

      Select one or more objects from the Source Objects section and click the Rightwards arrow icon to add the objects to the Selected Objects section.

      Rename Databases and Tables
      • To rename an object that you want to migrate to the destination instance, right-click the object in the Selected Objects section. For more information, see Map the name of a single object.
      • To rename multiple objects at a time, click Batch Edit in the upper-right corner of the Selected Objects section. For more information, see Map multiple object names at a time.
      Note 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.
      Filter data

      You can specify WHERE conditions to filter data. For more information, see Use SQL conditions to filter data.

      Select the SQL operations to be migrated In the Selected Objects section, right-click an object. In the dialog box that appears, select the DDL and DML operations that you want to migrate.
    • Advanced Settings
      Parameter Description
      Set Alerts
      Specifies whether to set alerts for the data migration task. If the task fails or the migration latency exceeds the threshold, the alert contacts will receive notifications. Valid values:
      • No: does not set alerts.
      • Yes: sets alerts. If you select Yes, you must also set the alert threshold and alert contacts.
      Replicate Temporary Tables When DMS Performs DDL Operations
      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. Valid values:
      • Yes: DTS migrates the data of temporary tables generated by online DDL operations.
        Note If online DDL operations generate a large amount of data, the data migration task may take an extended period of time to complete.
      • 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.
      Retry Time for Failed Connection
      The retry time range for failed connections. Unit: minutes. Valid values: 10 to 720. Default value: 720. We recommend that you set the retry time range to more than 30 minutes. If DTS reconnects to the source and destination databases within the specified time range, DTS resumes the data migration task. Otherwise, the data migration task fails.
      Note
      • If you set different retry time ranges for multiple data migration tasks that have the same source or destination database, the value that is set later takes precedence.
      • When DTS retries a connection, you are charged for the DTS instance. We recommend that you specify the retry time range based on your business requirements. You can also release the DTS instance at the earliest opportunity after the source and destination instances are released.
      Configure ETL
      Specify whether to configure the extract, transform, and load (ETL) feature. For more information, see What is ETL?.
  6. In the lower part of the page, click Next: Save Task Settings and Precheck.
    Note
    • Before you can start the data migration task, DTS performs a precheck. You can start the data migration task only after the task passes the precheck.
    • If the task fails to pass the precheck, you can click the Info icon icon next to each failed item to view details.
      • You can troubleshoot the issues based on the causes and run a precheck again.
      • If you do not need to troubleshoot the issues, you can ignore failed items and run a precheck again.
  7. Wait until the Success Rate becomes 100%. Then, click Next: Purchase Instance.
  8. On the Purchase Instance page, specify the Instance Class parameter for the data migration instance. The following table describes the parameter.
    Section Parameter Description
    Parameters Instance Class

    DTS provides several instance classes that have different performance in migration speed. You can select an instance class based on your business scenario. For more information, see Specifications of data migration instances.

  9. Read and select Data Transmission Service (Pay-as-you-go) Service Terms.
  10. Click Buy and Start to start the data migration task. You can view the progress of the task in the task list.

FAQ

The following table describes common alert messages and the corresponding solutions when you configure the source and destination instances.

Alert message Solution
UID错误提示 Check whether the ID of the Alibaba Cloud account that owns the source instance and the RAM role name configured for the account are valid.
Note To obtain the ID of the Alibaba Cloud account that owns the source instance and the RAM role name configured for the account, you can log on to the Account Management console by using this account. The account ID is displayed on the Security Settings page.
角色错误提示