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Data Transmission Service:Migrate data from an Amazon Aurora MySQL cluster to an ApsaraDB RDS for MySQL instance

Last Updated:Jul 14, 2023

This topic describes how to migrate data from an Amazon Aurora MySQL cluster to an ApsaraDB RDS for MySQL instance by using Data Transmission Service (DTS). DTS supports schema migration, full data migration, and incremental data migration. When you configure a data migration task, you can select all of the supported migration types to ensure service continuity.

Prerequisites

  • The Public accessibility option of the Amazon Aurora MySQL cluster is set to Yes. The setting ensures that DTS can access the Amazon Aurora MySQL cluster over the Internet.

  • An ApsaraDB RDS for MySQL instance is created. For more information, see Create an ApsaraDB RDS for MySQL instance.

  • The available storage space of the ApsaraDB RDS for MySQL instance is larger than the total size of the data in the Amazon Aurora MySQL cluster.

Limits

  • DTS uses read and write resources of the source and destination databases during full data migration. This may increase the loads of the database servers. If the database performance is unfavorable, the specification is low, or the data volume is large, database services may become unavailable. For example, DTS occupies a large amount of read and write resources in the following cases: a large number of slow SQL queries are performed on the source database, the tables have no primary keys, or a deadlock occurs in the destination database. Before you migrate data, evaluate the impact of data migration on the performance of the source and destination databases. We recommend that you migrate data during off-peak hours. For example, you can migrate data when the CPU utilization of the source and destination databases is less than 30%.
  • The tables to be migrated in the source database must have PRIMARY KEY or UNIQUE constraints and all fields must be unique. Otherwise, the destination database may contain duplicate data records.
  • DTS uses the ROUND(COLUMN,PRECISION) function to retrieve values from columns of the FLOAT or DOUBLE data type. If you do not specify a precision, DTS sets the precision for the FLOAT data type to 38 digits and the precision for the DOUBLE data type to 308 digits. You must check whether the precision settings meet your business requirements.
  • DTS automatically creates a destination database in the ApsaraDB RDS for MySQL instance. However, if the name of the source database is invalid, you must manually create a database in the ApsaraDB RDS for MySQL instance before you configure the data migration task.
    Note For more information about the database naming conventions of ApsaraDB RDS for MySQL databases and how to create a database, see Create a database for an ApsaraDB RDS for MySQL instance.
  • If a data migration task fails, DTS automatically resumes the task. Before you switch your workloads to the destination instance, stop or release the data migration task. Otherwise, the data in the source database overwrites the data in the destination instance after the task is resumed.

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.

Migration types

  • Schema migration

    DTS migrates the schemas of objects to the ApsaraDB RDS for MySQL instance. DTS supports schema migration for the following types of objects: table, view, trigger, stored procedure, and stored function. DTS does not support schema migration for events.

    Note
    • During schema migration, DTS changes the value of the SECURITY attribute from DEFINER to INVOKER for views, stored procedures, and stored functions.

    • DTS does not migrate user information. To call a view, stored procedure, or stored function of the destination database, you must grant the read and write permissions to INVOKER.

  • Full data migration

    DTS migrates the existing data of objects from the Amazon Aurora MySQL cluster to the ApsaraDB RDS for MySQL instance.

    Note

    During full data migration, concurrent INSERT operations cause fragmentation in the tables of the destination database. After full data migration is complete, the size of used tablespace of the destination database is larger than that of the source database.

  • Incremental data migration

    After full data migration is complete, DTS retrieves binary log files from the Amazon Aurora MySQL cluster. Then, DTS synchronizes incremental data from the Amazon Aurora MySQL cluster to the ApsaraDB RDS for MySQL instance. Incremental data migration allows you to ensure service continuity when you migrate data between MySQL databases.

Permissions required for database accounts

Database

Schema migration

Full data migration

Incremental data migration

Amazon Aurora MySQL cluster

SELECT permission on the objects to be migrated

SELECT permission on the objects to be migrated

SELECT permission on the objects to be migrated, REPLICATION SLAVE permission, REPLICATION CLIENT permission, and SHOW VIEW permission

ApsaraDB RDS for MySQL instance

Read and write permissions on the objects to be migrated

Read and write permissions on the objects to be migrated

Read and write permissions on the objects to be migrated

For more information about how to create a database account and grant permissions to the database account, see the following topics:

Before you begin

  1. Log on to the Amazon Aurora console.

  2. Go to the basic information page of the Amazon Aurora MySQL cluster.

  3. Select the node that assumes the Writer role.

  4. In the Connectivity & security section, click the name of the VPC security group that corresponds to the writer node.

    安全组规则
  5. On the Security Groups page, click the Inbound tab in the Security Group section. On the Inbound tab, click Edit. In the Edit inbound rules dialog box, add the CIDR blocks of DTS servers that reside in the corresponding region to the inbound rule. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.

    编辑入站规则
    Note
    • You need to add only the CIDR blocks of DTS servers that reside in the same region as the destination database. For example, the source database resides in the Singapore region and the destination database resides in the China (Hangzhou) region. You need to add only the CIDR blocks of DTS servers that reside in the China (Hangzhou) region.

    • You can add all of the required CIDR blocks to the inbound rule at a time.

  6. Log on to the Amazon Aurora MySQL cluster and specify the number of hours to retain binary log files. Skip this step if you do not need to perform incremental data migration.

    call mysql.rds_set_configuration('binlog retention hours', 24);
    Note
    • The preceding statement sets the retention period of binary log files to 24 hours. The maximum retention period is 168 hours, which equals seven days.

    • The binary logging feature of the Amazon Aurora MySQL cluster must be enabled and the value of the binlog_format parameter must be set to row. If the MySQL version is 5.6 or later, the value of the binlog_row_image parameter must be set to full.

Procedure (in the new DTS console)

  1. Go to the Data Migration Tasks page.
    1. Log on to the Data Management (DMS) console.
    2. In the top navigation bar, click DTS.
    3. In the left-side navigation pane, choose DTS (DTS) > Data Migration.
    Note
  2. From the drop-down list next to Data Migration Tasks, select the region in which the data migration instance resides.
    Note If you use the new DTS console, you must select the region in which the data migration instance resides in the upper-left corner.
  3. Click Create Task. On the Create Task wizard page, configure the source and destination databases.

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

    Section

    Parameter

    Description

    N/A

    Task Name

    The task name that DTS automatically generates. We recommend that you specify a descriptive name that makes it easy to identify the task. You do not need to specify a unique task name.

    Source Database

    Select an existing DMS database instance

    The database instance that you want to use. You can choose whether to select an existing instance based on your business requirements.
    • If you select an existing instance, DTS automatically populates the parameters for the database.
    • If you do not select an existing instance, you must manually configure parameters for the database.

    Database Type

    The type of the source database. Select MySQL.

    Access Method

    The access method of the source database. Select Public IP Address.

    Instance Region

    The region in which the Amazon Aurora MySQL cluster resides.

    Note

    If the region in which the Amazon Aurora MySQL cluster resides is not displayed in the drop-down list, select a region that is geographically closest to the Amazon Aurora MySQL cluster.

    Hostname or IP Address

    The endpoint that is used to access the Amazon Aurora MySQL cluster.

    Note

    You can obtain the endpoint on the basic information page of the Amazon Aurora MySQL cluster.

    Port Number

    The service port number of the Amazon Aurora MySQL cluster. Default value: 3306.

    Database Account

    The database account of the Amazon Aurora MySQL cluster. For information about the permissions that are required for the account, see the Permissions required for database accounts section of this topic.

    Database Password

    The password of the database account.

    Destination Database

    Select an existing DMS database instance

    The database instance that you want to use. You can choose whether to select an existing instance based on your business requirements.
    • If you select an existing instance, DTS automatically populates the parameters for the database.
    • If you do not select an existing instance, you must manually configure parameters for the 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 for MySQL instance resides.

    RDS instance ID

    The ID of the destination ApsaraDB RDS for MySQL instance.

    Database Account

    The database account of the destination ApsaraDB RDS for MySQL instance. For information about the permissions that are required for the account, 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 business requirements. If you select SSL-encrypted, you must enable SSL encryption for the ApsaraDB RDS for MySQL instance before you configure the data migration task. For more information, see Configure SSL encryption for an ApsaraDB RDS for MySQL instance.

  4. In the lower part of the page, click Test Connectivity and Proceed.
  5. If an IP address whitelist is configured for your self-managed database, you must add the CIDR blocks of DTS servers to the IP address whitelist. Then, click Test Connectivity and Proceed.
    Warning If the CIDR blocks of DTS servers are automatically or manually added to the IP address whitelist of the 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: enhance the security of your account and password, limit the ports that are exposed, authenticate API calls, regularly check the IP address whitelist or ECS security group rules and forbid unauthorized CIDR blocks, and connect the database to DTS by using Express Connect, VPN Gateway, or Smart Access Gateway.
  6. Configure the objects to be migrated and the advanced settings.

    Parameter

    Description

    Migration Type

    • 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 you do not select Incremental Data Migration, we recommend that you do not write data to the source database during data migration. This ensures data consistency between the source and destination databases.

    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 inconsistency may occur, 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. Proceed with caution.

    Method to Migrate Triggers in Source Database

    The method used to migrate triggers from the source database. You can select a migration method based on your business requirements. If no triggers are to be migrated, you do not need to configure this parameter. For more information, see Synchronize or migrate triggers from the source database.

    Note

    You can configure this parameter only when you select Schema Migration as a migration type.

    Enable Migration Assessment

    Specifies whether to enable migration assessment. Migration assessment aims to check whether the schemas of the source and destination databases, such as the length of indexes, stored procedures, and dependent tables, meet the requirements. You can select Yes or No based on your business requirements.

    Note
    • You can configure this parameter only when you select Schema Migration as a migration type.

    • If you select Yes, the precheck may take more time. You can view the Assessment Result during the precheck. The assessment results do not affect the precheck results.

    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.

    Source Objects

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

    Note You can select columns, tables, or schemas 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.

    Selected Objects

    • 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 depend on the object may fail to be migrated.

    • To specify WHERE conditions to filter data, right-click a table in the Selected Objects section. In the dialog box that appears, specify the conditions. For more information, see Use SQL conditions to filter data.

    • To migrate the SQL operations performed on a specific database or table, right-click the object in the Selected Objects section. In the dialog box that appears, select the SQL operations that you want to migrate.

  7. Click Next: Advanced Settings to configure advanced settings.

    • Data Verification Settings

      For more information about how to use the data verification feature, see Enable data verification.

    • Advanced Settings

      Parameter

      Description

      Select the dedicated cluster used to schedule the task

      By default, DTS schedules the task to a shared cluster. You do not need to configure this parameter. You can purchase a dedicated cluster of the specified specifications to run data migration tasks. For more information, see What is a DTS dedicated cluster?

      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:

      Copy the temporary table of the Online DDL tool that is generated in the source table to the destination database

      If you use DMS or the gh-ost tool to perform online DDL operations on the source database, you can specify whether to migrate the temporary tables generated by online DDL operations. Valid values:
      Important You cannot use tools such as pt-online-schema-change to perform online DDL operations on the source database. Otherwise, the DTS task fails.
      • 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, Adapt to DMS Online DDL: DTS does not migrate the data of temporary tables generated by online DDL operations. Only the original DDL operations that are performed by using DMS are migrated.
        Note If you select No, Adapt to DMS Online DDL, the tables in the destination database may be locked.
      • No, Adapt to gh-ost: DTS does not migrate the data of temporary tables generated by online DDL operations. Only the original DDL operations that are performed by using the gh-ost tool are migrated. You can use the default or custom regular expressions to filter out the shadow tables of the gh-ost tool and tables that are not required.
        Note If you select No, Adapt to gh-ost, the tables in the destination database may be locked.

      Retry Time for Failed Connections

      The retry time range for failed connections. If the source or destination database fails to be connected after the data migration task is started, DTS immediately retries a connection within the time range. Valid values: 10 to 1440. Unit: minutes. Default value: 720. We recommend that you set the parameter to a value greater than 30. 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 shortest retry time range that is set 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 your earliest opportunity after the source and destination instances are released.

      The wait time before a retry when other issues occur in the source and destination databases.

      The retry time range for other issues. For example, if the DDL or DML operations fail to be performed after the data migration task is started, DTS immediately retries the operations within the time range. Valid values: 1 to 1440. Unit: minutes. Default value: 10. We recommend that you set the parameter to a value greater than 10. If the failed operations are successfully performed within the specified time range, DTS resumes the data migration task. Otherwise, the data migration task fails.
      Important The value of the The wait time before a retry when other issues occur in the source and destination databases parameter must be smaller than the value of the Retry Time for Failed Connections parameter.

      Enable Throttling for Full Data Migration

      During full data migration, DTS uses the read and write resources of the source and destination databases. This may increase the loads on the database servers. You can specify whether to enable throttling for the full data migration task. If you select Yes, you can configure the Query Rate on Source Database, RPS of Full Data Migration, and BPS of Full Data Migration parameters based on your business requirements to relieve the load on the destination instance.

      Note

      You can configure this parameter only when you select Full Data Migration as a migration type.

      Enable Throttling for Incremental Data Migration

      You can specify whether to enable throttling for the incremental data migration task. If you select Yes, you can configure the RPS of Incremental Data Migration and BPS of Incremental Data Migration parameters based on your business requirements to relieve the load on the destination instance.

      Note

      You can configure this parameter only when you select Incremental Data Migration as a migration type.

      Configure ETL

      Specifies whether to configure the extract, transform, and load (ETL) feature. For more information, see What is ETL?. Valid values:

      Whether to delete SQL operations on heartbeat tables of forward and reverse tasks

      Specifies whether to write SQL operations on heartbeat tables to the source database while the DTS instance is running.
      • Yes: does not write SQL operations on heartbeat tables. In this case, a latency of the DTS instance may be displayed.
      • No: writes SQL operations on heartbeat tables. In this case, specific features such as physical backup and cloning of the source database may be affected.
  8. In the lower part of the page, click Next: Save Task Settings and Precheck.

    You can move the pointer over Next: Save Task Settings and Precheck and click Preview OpenAPI parameters to view the parameters to be specified when you call the relevant API operation to configure the DTS task.

    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, click View Details next to each failed item. After you troubleshoot the issues based on the causes, run a precheck again.
    • If an alert is triggered for an item during the precheck:
      • If an alert item cannot be ignored, click View Details next to the failed item and troubleshoot the issues. Then, run a precheck again.
      • If an alert item can be ignored, click Confirm Alert Details. In the View Details dialog box, click Ignore. In the message that appears, click OK. Then, click Precheck Again to run a precheck again. If you ignore the alert item, data inconsistency may occur, and your business may be exposed to potential risks.
  9. Wait until the Success Rate value becomes 100%. Then, click Next: Purchase Instance.
  10. On the Purchase Instance page, specify the Instance Class parameter for the data migration instance. The following table describes the parameter.
    SectionParameterDescription
    New Instance ClassResource GroupThe resource group to which the data migration instance belongs. Default value: default resource group. For more information, see What is Resource Management?.
    Instance Class

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

  11. Read 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. You can view the progress of the task in the task list.

Procedure (in the old DTS console)

  1. Log on to the DTS console.
    Note If you are redirected to the Data Management (DMS) console, you can click the old icon in the lower-right corner to go to the previous version of the DTS console.
  2. In the left-side navigation pane, click Data Migration.
  3. At the top of the Migration Tasks page, select the region where the destination cluster resides.
  4. In the upper-right corner of the page, click Create Migration Task.
  5. Configure the source and destination databases.

    源库和目标库连接配置

    Section

    Parameter

    Description

    N/A

    Task Name

    The task name that DTS automatically generates. We recommend that you specify a descriptive name that makes it easy to identify the task. You do not need to specify a unique task name.

    Source Database

    Instance Type

    The instance type of the source database. Select User-Created Database with Public IP Address.

    Instance Region

    The region in which the source database resides. If you select User-Created Database with Public IP Address as the instance type of the source database, you do not need to configure the Instance Region parameter.

    Database Type

    The type of the source database. Select MySQL.

    Hostname or IP Address

    The endpoint that is used to access the Amazon Aurora MySQL cluster.

    Note

    You can obtain the endpoint on the basic information page of the Amazon Aurora MySQL cluster.

    连接地址

    Port Number

    The service port number of the Amazon Aurora MySQL cluster. Default value: 3306.

    Database Account

    The database account of the Amazon Aurora MySQL cluster. For information about the permissions that are required for the account, see the Permissions required for database accounts section of this topic.

    Database Password

    The password of the database account.

    Note

    After you specify the information about the self-managed Oracle database, you can click Test Connectivity next to Database Password to check whether the information is valid. If the information is valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Then, modify the information based on the check results.

    Destination Database

    Instance Type

    The instance type of the destination database. Select RDS Instance.

    Instance Region

    The region in which the ApsaraDB RDS for MySQL instance resides.

    RDS Instance ID

    The ID of the ApsaraDB RDS for MySQL instance.

    Database Account

    The database account of the destination ApsaraDB RDS for MySQL instance. For information about the permissions that are required for the account, see the Permissions required for database accounts section of this topic.

    Database Password

    The password of the database account.

    Note

    After you specify the information about the destination database, you can click Test Connectivity next to Database Password to check whether the information is valid. If the information is valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Then, modify the information based on the check results.

    Encryption

    Specifies whether to encrypt the connection to the source instance. Select Non-encrypted or SSL-encrypted based on your business requirements. If you select SSL-encrypted, you must enable SSL encryption for the ApsaraDB RDS for MySQL instance before you configure the data migration task. For more information, see Configure SSL encryption for an ApsaraDB RDS for MySQL instance.

    Note

    The Encryption parameter is displayed only for regions in the Chinese mainland and the China (Hong Kong) region.

  6. In the lower-right corner of the page, click Set Whitelist and Next.

    If the source or destination database instance is an Alibaba Cloud database instance, such as an 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. If the source or 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. For more information about the CIDR blocks of DTS servers, see the "CIDR blocks of DTS servers" section of the Add the CIDR blocks of DTS servers to the security settings of on-premises databases topic.

    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.
  7. Select the objects to be migrated and the migration types.

    选择迁移对象和类型

    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, we recommend that you 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 向右小箭头 icon to move the objects to the Selected section.

    Note
    • You can select columns, tables, or databases as the objects to be migrated.

    • By default, after an object is migrated to the destination database, the name of the object remains unchanged in the destination database. 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.

    • If you use the object name mapping feature to rename an object, other objects that depend 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 a failed connection to the source or destination database

    By default, if DTS fails to connect to the source or destination database, DTS retries within the next 12 hours. You can specify the retry time range based on your business requirements. If DTS reconnects to the source and destination databases within the specified retry 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 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.

    Specify whether to copy temporary tables to the destination database when DMS performs online DDL operations on the source table

    If you use Data Management (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, 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 ApsaraDB RDS for MySQL instance may be locked.

  8. In the lower-right corner of the page, click 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.
  9. After the task passes the precheck, click Next.
  10. In the Confirm Settings dialog box, specify the Channel Specification parameter and select Data Transmission Service (Pay-As-You-Go) Service Terms.
  11. Click Buy and Start to start the data migration task.
    • Schema migration and full data migration

      We recommend that you do not manually stop the task during full data migration. Otherwise, the data migrated to the destination database may be incomplete. You can wait until the data migration task automatically stops.

    • Schema migration, full data migration, and incremental data migration

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

      Important We recommend that you select an appropriate time to manually stop the data migration task. For example, you can stop the task during off-peak hours or before you switch your workloads to the destination cluster.
      1. Wait until Incremental Data Migration and The migration task is not delayed appear in the progress bar of the 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 migration task is not delayed again. Then, manually stop the migration task. Stop an incremental data migration task
  12. Switch your workloads to the destination ApsaraDB RDS for MySQL instance.