Data Transmission Service:Migrate data from a self-managed HBase database to an AnalyticDB for MySQL V3.0 cluster

Prerequisites

• The database versions of the self-managed HBase database and the AnalyticDB for MySQL V3.0 cluster are supported by DTS. For more information , see Overview of data migration scenarios.
• The destination AnalyticDB for MySQL V3.0 cluster is created. For more information, see Create a cluster.
• The available storage space of the destination AnalyticDB for MySQL V3.0 cluster is larger than the total size of the data in the self-managed HBase database.

Limits

Billing

Migration types

• Schema migration

  DTS migrates the schemas of required objects from the source database to the destination database.

  DTS supports schema migration for tables.
  Note DTS can migrate the tables of an entire database or a single table.
• Full data migration

  DTS migrates historical data of required objects from the source database to the destination database.

Permissions required for database accounts

Procedure

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 You can also configure the settings by using the new DTS console.
2. From the drop-down list to the right of Data Migration Tasks, select the region in which your data migration instance resides.
   Note If you use the new DTS console, select the region in which your data migration instance resides in the upper-left corner.
3. Click Create Task. On the page that appears, configure the source and destination databases.
   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 HBase.
   	Access Method	The access method of the source database. Select Public IP Address. Note If your source database is a self-managed database, you must deploy the network environment for the database. For more information, see Preparation overview.
   	Instance Region	The region in which the self-managed HBase database resides.
   	ZooKeeper URL	The endpoints of the ZooKeeper servers that are configured for the self-managed HBase database. Enter each endpoint in the <IP address> or <Domain name:Port number> format. Separate multiple endpoints with commas (,).
   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 AnalyticDB for MySQL 3.0.
   	Access Method	The access method of the destination database. Select Alibaba Cloud Instance.
   	Instance Region	The region in which the destination AnalyticDB for MySQL V3.0 cluster resides.
   	Instance ID	The ID of the destination AnalyticDB for MySQL V3.0 cluster.
   	Database Account	The database account of the destination AnalyticDB for MySQL V3.0 cluster. For information about the permissions that are required for the account, see Permissions required for database accounts.
   	Database Password	The password of the database account.

4. If a whitelist is configured for your self-managed database, add the CIDR blocks of DTS servers to the whitelist. Then, click Test Connectivity and Proceed.
   Warning

   • 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. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases. 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.
   • 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 of the database, Alibaba Cloud database instance, or ECS security group rules.
5. Select objects for the task and configure advanced settings.
   • Basic Settings

     Parameter	Description
     Task Stages	Schema Migration and Full Data Migration are selected by default. Note In this scenario, DTS does not support incremental data migration. To ensure data consistency, we recommend that you do not write data to the source database during data migration. The schema of and data in the table that is created by executing the CREATE TABLE statement can be migrated to the destination database.
     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.
     Merge Tables	Yes: If you select this value, DTS adds the __dts_data_source column to each table to record data sources. For more information, see Enable the multi-table merging feature. No: This value is selected by default. Note If you set this parameter to Yes, all the selected source tables in the task are merged into a single destination table. If you do not need to merge specific source tables, you can create a separate data migration task for these tables. Warning We recommend that you do not perform DDL operations to change the schemas of source databases or tables. Otherwise, data inconsistency may occur or the data migration task fails.
     Source Objects	Select one or more objects from the Source Objects section and click the icon to add the objects to the Selected Objects section. Note You can select tables or databases as the objects to be migrated. If you select tables as the objects to be migrated, DTS does not migrate other objects such as views, triggers, or stored procedures to the destination database. If you select a database as the object to be migrated, DTS migrates data based on the following default rules: If the table to be migrated in the source database has a primary key, such as a single-column primary key or a composite primary key, the primary key columns are specified as the distribution keys. If the table to be migrated in the source database does not have a primary key, an auto-increment primary key column is automatically generated in the destination table. This may cause data inconsistency between the source and destination databases.
     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 are dependent on the object may fail to be migrated. To specify WHERE conditions to filter data, right-click an object in the Selected Objects section. In the dialog box that appears, specify the conditions. For more information, see Use SQL conditions to filter data.

   • 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.
     Retry Time for Failed Connections	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.
     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.
     Configure ETL	Specify whether to configure the extract, transform, and load (ETL) feature. For more information, see What is ETL?. Yes: configures the ETL feature. You can enter data processing statements in the code editor. For more information, see Configure ETL in a data migration or data synchronization task. No: does not configure the ETL feature.

6. Specify the primary key columns and distribution keys of the tables that you want to migrate to the AnalyticDB for MySQL cluster.
   Note

   • If you select Schema Migration as the migration type, you must specify the type, primary key column, and distribution key for the tables that you want to migrate to the AnalyticDB for MySQL V3.0 cluster. For more information, see CREATE TABLE.
   • In the Primary Key Column field, you can specify multiple columns to form a composite primary key. In this case, you must specify one or more primary key columns as the distribution keys.
7. 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 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.
8. Wait until the Success Rate becomes 100%. Then, click Next: Purchase Instance.
9. 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.

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