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    Data Transmission Service:Migrate PolarDB-X 1.0 to AnalyticDB for MySQL 3.0

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    Data Transmission Service:Migrate PolarDB-X 1.0 to AnalyticDB for MySQL 3.0

    Last Updated:Jun 27, 2026

    This topic describes how to migrate data from a PolarDB-X 1.0 instance to an AnalyticDB for MySQL 3.0 cluster using Data Transmission Service (DTS).

    Prerequisites

    • You have a source PolarDB-X 1.0 instance. For more information, see Create a PolarDB-X 1.0 instance.

      Note

      The PolarDB-X 1.0 instance must use ApsaraDB RDS for MySQL as its storage type. This includes both privately customized and separately purchased RDS instances. PolarDB for MySQL is not supported.

    • If you need to perform an incremental data migration, ensure the source data's character set is not utf8mb3. Otherwise, the migration will fail.

    • You have a destination AnalyticDB for MySQL V3.0 cluster. The cluster's storage space must exceed the storage used by the source PolarDB-X 1.0 instance. For more information, see Create a cluster.

    Limitations

    Note

    • During schema migration, DTS does not migrate foreign keys from the source database to the destination database.

    • During full data migration and incremental data migration, DTS temporarily disables constraint checks and foreign key cascading operations at the session level. If cascading update or delete operations occur in the source database while the task is running, data inconsistency may occur.

    • During schema migration, DTS does not support migrating materialized views to the destination AnalyticDB for MySQL instance. To use materialized views, manually create them in the destination instance after migration is complete.

    Type

    Description

    Source database limitations

    • Bandwidth requirements: The server that hosts the source database must have sufficient outbound bandwidth. Insufficient bandwidth will slow down the data migration.

    • Tables to be migrated must have a PRIMARY KEY or a UNIQUE constraint, and the fields in the key or constraint must be unique. Otherwise, this may cause duplicate data in the destination database.

    • If you migrate objects at the table level and need to edit them, for example, by mapping column names, a single data migration task supports a maximum of 1,000 tables. If you exceed this limit, the task submission will fail. In this case, split the tables into multiple data migration tasks or configure a task to migrate the entire database.

    • For incremental data migration, the source database must meet the following binary log requirements:

      • Enable the binary log feature, and set the binlog_row_image parameter to full. Otherwise, the precheck fails and the data migration task cannot start.

      • For incremental data migration tasks, DTS requires that the binary logs of the source database be retained for at least 24 hours. For tasks that include both full data migration and incremental data migration, the binary logs must be retained for at least 7 days. You can change the retention period to 24 hours after the full data migration is complete. If the binary logs are not retained for the required period, DTS may fail to obtain them, which can cause task failures or even data inconsistency and loss. The DTS SLA does not cover issues caused by an insufficient binary log retention period.

    • Operational restrictions on the source database:

      • During data migration, do not perform operations such as scaling out, scaling in, migrating hot-spot tables, changing the sharding key, or executing DDL statements. Otherwise, the data migration task will fail.

        Note

        During the full migration phase, DTS queries the source database. This creates a metadata lock, which may block DDL operations on the source database.

      • If the partition key is changed in the source database and the primary key in the target table does not include the source partition key, data loss may occur in the target database.

        • Reason: A PolarDB-X 1.0 instance has multiple RDS for MySQL instances attached to it. DTS creates a separate migration link for each RDS for MySQL instance. A change to a partition key causes data to be deleted from one RDS for MySQL instance and inserted into another. Because the links execute independently, the execution order of the DELETE and INSERT operations is not guaranteed. If the primary key of the target database does not include the partition key, a DELETE operation that executes later may accidentally delete the newly inserted data.

        • Recommendation: To prevent data loss caused by out-of-order operations, ensure that the primary key of the target table includes the partition key column from the source database.

      • During full and incremental migration, DTS temporarily disables constraint checks and foreign key cascading operations at the session level. If cascading update or delete operations occur on the source database while the task is running, data inconsistency may occur.

      • If you switch the network type of the PolarDB-X 1.0 instance during migration, update the migration link's network connection information after the switch is complete.

      • If you perform only full data migration, do not write new data to the source database during the migration. Otherwise, data will become inconsistent between the source and destination databases. To maintain real-time data consistency, select schema migration, full data migration, and incremental data migration.

    • PolarDB-X 1.0 must be compatible with MySQL 5.7.

    • The source PolarDB-X 1.0 instance must be version 5.2 or later.

    • Do not change the type of a broadcast table in the source PolarDB-X 1.0 instance while a DTS migration task is running (for example, from a broadcast table to a single table or a sharded table). If you need to change the table type, stop the migration task. After the change is complete, reconfigure the migration task.

    Other limitations

    • DTS does not support migrating INDEX, PARTITION, VIEW, PROCEDURE, FUNCTION, TRIGGER, and FK objects.

    • DTS relies on the continuity of XA transactions in the source PolarDB-X 1.0 instance to ensure data consistency for incremental migration tasks. If the continuity of XA transactions is broken, for example, during a disaster recovery scenario for the incremental data capture module, uncommitted XA transactions may be lost.

    • The destination database must have a custom primary key. Or, in the Configurations for Databases, Tables, and Columns step, set the Primary Key Column. Otherwise, migration may fail.

    • Before you perform data migration, evaluate the performance of the source and destination databases. Perform data migration during off-peak hours. Otherwise, the full data migration consumes read and write resources from both databases, increasing the database load.

    • During full data migration, DTS runs concurrent INSERT operations, which can cause table fragmentation in the destination database. As a result, tables in the destination database will occupy more storage space than those in the source instance.

    • DTS attempts to resume a failed migration task within seven days. Therefore, before you switch your business to the destination instance, you must end or release the task, or use the revoke command to revoke the write permissions from the account that DTS uses to access the destination instance. This prevents the source data from overwriting the data in the destination instance if the task is automatically resumed.

    • If the destination AnalyticDB for MySQL 3.0 cluster is backing up while the DTS task runs, the task fails.

    • If a task fails, DTS support staff will attempt to restore it within eight hours. During restoration, they may restart the task or adjust its parameters.

      Note

      Only DTS task parameters are modified—not database parameters. Parameters that may be adjusted include those listed in Modify instance parameters.

    • When the destination database is AnalyticDB for MySQL 3.0, DTS supports writing only the data types supported by that database, including Basic Data Types and Complex Data Types such as ARRAY, MAP, and JSON. Other types like MULTIVALUE are not supported.

    Additional considerations

    DTS periodically updates the dts_health_check.ha_health_check table in the source database to advance the binlog position.

    Billing

    Migration type

    Instance configuration fee

    Internet traffic fee

    Schema migration and full data migration

    Free.

    Free in this example.

    Incremental data migration

    Charged. See Billing overview for more information.

    Migration types

    • Schema migration

      DTS migrates the schema definitions of the migration objects from the source database to the destination database.

    • Full migration

      DTS migrates all historical data of the specified migration objects from the source database to the destination database.

    • Incremental migration

      After a full migration is complete, DTS migrates incremental data updates from the source database to the destination database. Incremental migration lets you smoothly migrate data without interrupting your self-managed applications.

    Supported SQL operations for incremental migration

    Operation type

    SQL statement

    DML

    INSERT, UPDATE, DELETE

    Note

    When you write data to AnalyticDB for MySQL, it automatically converts UPDATE statements to REPLACE INTO. If you update a primary key, it converts the UPDATE statement to a DELETE followed by an INSERT.

    Permission requirements for database accounts

    Database

    Schema migration

    Full data migration

    Incremental data migration

    PolarDB-X 1.0 instance

    SELECT privilege

    SELECT privilege

    REPLICATION SLAVE, REPLICATION CLIENT, and SELECT privileges on the objects to be migrated.

    Note

    For information on granting privileges, see Account permissions for data synchronization.

    AnalyticDB for MySQL V3.0 cluster

    read and write permissions

    To create a database account and grant privileges:

    Data type mappings

    For details, see Data type mappings for schema initialization.

    Procedure

    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

      None

      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 PolarDB-X 1.0.

      Connection Type

      Select Alibaba Cloud Instance.

      Instance Region

      Select the region where the source PolarDB-X 1.0 instance is located.

      Replicate Data Across Alibaba Cloud Accounts

      In this example, a database instance under the current Alibaba Cloud account is used. Select No.

      Instance ID

      Select the ID of the source PolarDB-X 1.0 instance.

      Database Account

      Enter the database account for the source PolarDB-X 1.0 instance. For details on the required permissions, see Permissions required 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 AnalyticDB for MySQL 3.0.

      Connection Type

      Select Alibaba Cloud Instance.

      Instance Region

      Select the region where the destination AnalyticDB for MySQL cluster is located.

      Instance ID

      Select the ID of the destination AnalyticDB for MySQL cluster.

      Database Account

      Enter the database account for the destination AnalyticDB for MySQL cluster. For details on the required permissions, see Permissions required 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.

      Note

      Ensure that the DTS service IP address segments 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

        • If you only need to perform a full migration, select both Schema Migration and Full Data Migration.

        • To perform a migration with no downtime, select Schema Migration, Full Data Migration, and Incremental Data Migration.

        Note

        • If you do not select Schema Migration, you must ensure that a database and tables to receive the data exist in the destination database. You can also use the object name mapping feature in the Selected Objects box as needed.

        • If you do not select Incremental Data Migration, do not write new data to the source instance during data migration to ensure data consistency.

        DDL and DML Operations to Be Synchronized

        Select the SQL operations for incremental data migration at the instance level. For more information about the supported operations, see Supported SQL operations for incremental migration.

        Note

        To select the SQL operations for incremental migration at the database or table level, right-click a migration object in the Selected Objects box and select the desired SQL operations in the dialog box.

        Merge Tables

        • Yes: DTS adds a __dts_data_source column to each table to store the data source. For more information, see Enable multi-table merging.

          Note

          The table merging feature is configured at the task level, not at the table level. If you want to merge some tables but not others, you can create two separate data migration tasks.

        • No: This is the default option.

        Warning

        Do not perform DDL operations to change the schema of the source database or tables. Otherwise, data inconsistency may occur or the migration task may fail.

        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.

        Capitalization of Object Names in Destination Instance

        You can configure the case sensitivity policy for the names of migrated objects, such as databases, tables, and columns, in the destination instance. By default, DTS default policy is selected. You can also choose to keep the case sensitivity consistent with the default policy of the source or destination database. For more information, see Case sensitivity of object names in the destination database.

        Source Objects

        In the Source Objects box, click the objects to migrate, and then click Right arrow to move them to the Selected Objects box.

        Note

        • You can select databases or tables as migration objects.

        • If you select an entire database to migrate, the following default rules apply:

          • If a table to be migrated in the source database has a primary key (single-column or composite), the primary key columns are used as the distribution key.

          • If a table to be migrated in the source database does not have a primary key, DTS automatically generates an auto-incrementing primary key column. This may cause data inconsistency between the source and destination databases.

          • Changes such as adding or deleting tables in the source database are not migrated to the destination database.

        Selected Objects
        Note

        • If you use the object name mapping feature to rename an object, the migration of other objects that depend on it may fail.

        • To use WHERE conditions to filter data, right-click the table to migrate in the Selected Objects box and specify the filter conditions in the dialog box that appears. For more information, see Set filter conditions.

        • To select the SQL operations to migrate at the database or table level, right-click the migration object in the Selected Objects box and select the desired SQL operations in the dialog box that appears.

      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.

        Enable Throttling for Incremental Data Migration

        If required, you can also choose to set speed limits for the incremental migration task. You can set RPS of Incremental Data Migration and Data migration speed for incremental migration (MB/s) to reduce the load on the destination database.

        Note

        • This configuration item is available only if you select Incremental Data Migration for Migration Types.

        • You can also adjust the incremental migration speed after the migration instance is running.

        Environment Tag

        You can select an environment tag to identify the instance based on your business requirements. In this example, you do not need to select an environment tag.

        Configure ETL

        Based on your business needs, select whether to configure the ETL feature to process data.

        • Yes: Configures the ETL feature. You must also enter data processing statements in the text box.

        • No: Does not configure 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. Optional: After you complete the preceding configurations, click Next: Configure Database and Table Fields to set the Type, Primary Key Column, Distribution Key, and partition key information (Partition Key, Partitioning Rules, and Partition Lifecycle) for the tables to be migrated in the destination database.

        Note

        • This step is available only if you select Schema Migration for Migration Types. To modify the settings, set Definition Status to All.

        • In Primary Key Column, you can select multiple columns to form a composite primary key. You must then select one or more columns from Primary Key Column as the Distribution Key and Partition Key. For more information, see CREATE TABLE.

    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 the 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.