Synchronize data from an ApsaraDB RDS for MySQL instance to Tablestore

Precautions

• DTS uses the read and write resources of the source and destination databases during initial full data synchronization. This may increase the loads of the database servers. Before you synchronize data, evaluate the impact of data synchronization on the performance of the source and destination databases. We recommend that you synchronize data during off-peak hours.
• DTS does not synchronize data definition language (DDL) operations. If a DDL operation is performed on a table in the source database during data synchronization, you must perform the following steps: Remove the table from the required objects, remove the table from the Tablestore instance, and then add the table to the required objects. For more information see Remove an object from a data synchronization task and Add an object to a data synchronization task.
• You can synchronize at most 64 tables to the Tablestore instance. If you need to synchronize more than 64 tables to the Tablestore instance, submit a ticket to remove the limit.
• The names of the tables or columns to be synchronized must comply with the naming conventions of the Tablestore instance.
  • The name of a table or index can contain letters, digits, and underscores (_). The name must start with a letter or underscore (_).
  • The name of a table or index must be 1 to 255 characters in length.

Initial synchronization types

Before you begin

1. Create a RAM user and grant the AliyunOTSFullAccess permission on Tablestore to the RAM user.
   1. Log on to the RAM console.
   2. Create a RAM user.
   3. In the left-side navigation pane, choose Identities > Users.
   4. On the Users page, find the RAM user, and click Add Permissions in the Actions column.
      
   5. In the dialog box that appears, enter AliyunOTSFullAccess in the search box, and click the policy name to add the policy to the Selected section.
      
   6. Click OK.
   7. Click Finished.
2. Create an AccessKey pair for the RAM user. For more information, see Create an AccessKey pair.
3. Optional:If you need to configure a data synchronization task as a RAM user, you must grant the AliyunDTSDefaultRole permission to the RAM user. For more information, see Authorize DTS as a RAM user.
   Note If you use an Alibaba Cloud account to configure a data synchronization task, skip this step.

Procedure

1. Purchase a data synchronization instance. For more information, see Purchase a DTS instance.
   Note On the buy page, set Source Instance to MySQL, set Target Instance to Tablestore, and set Synchronization Topology to One-Way Synchronization.
2. Configure the source and destination databases.
   

   Section	Parameter	Description
   N/A	Synchronization Task Name	DTS automatically generates a task name. We recommend that you specify an informative name for easy identification. You do not need to use a unique task name.
   Source Instance Details	Instance Type	Select RDS Instance.
   	Instance Region	The source region that you selected on the buy page. You cannot change the value of this parameter.
   	Instance ID	Select the ID of the source RDS instance.
   	Database Account	Enter the database account of the source RDS instance. The account must have the SELECT permission on the required objects, the REPLICATION CLIENT permission, the REPLICATION SLAVE permission, and the SHOW VIEW permission. Note If the database engine of the source RDS instance is MySQL 5.5 or MySQL 5.6, you do not need to configure the database account or database password.
   	Database Password	Enter the password of the source database account.
   	Encryption	Select Non-encrypted or SSL-encrypted. If you want to select SSL-encrypted, you must enable SSL encryption for the RDS instance before you configure the data synchronization task. For more information, see Configure SSL encryption on an ApsaraDB RDS for MySQL instance. Notice The Encryption parameter is available only for regions in the Chinese mainland and the China (Hong Kong) region.
   Destination Instance Details	Instance Type	Select Tablestore.
   	Instance Region	The destination region that you selected on the buy page. You cannot change the value of this parameter.
   	Instance ID	Select the ID of the destination Tablestore instance.
   	AccessKeyId	Enter the AccessKey ID. For more information, see Create an AccessKey pair.
   	AccessKeySecrect	Enter the AccessKey secret.

3. In the lower-right corner of the page, click Set Whitelist and Next.
   In this step, DTS adds the CIDR blocks of DTS servers to the whitelists of the source and destination instances. This ensures that DTS servers can connect to the source and destination instances.
4. Configure the synchronization policy and the objects to be synchronized.
   1. Configure the synchronization policy.
      

      Parameter	Description
      Initial Synchronization	Select Initial Schema Synchronization, Initial Full Data Synchronization, and Initial Incremental Data Synchronization. For more information, see Initial synchronization types.
      Processing Mode In Existed Target Table
      Merge Multi Tables	Yes: In OLTP scenarios, sharding is implemented to speed up the response to business tables. You can merge multiple source tables that have the same schema into a single destination table. This feature allows you to synchronize data from multiple tables in the source database to a single table in the Tablestore instance. Note DTS adds a column named __dts_data_source to the destination table in the Tablestore instance. This column is used to record the data source. The data type of this column is varchar. DTS specifies the column values based on the following format: <Data synchronization instance ID>:<Source database name>.<Source table name>. Such column values allow DTS to identify each source table. For example, dts********:dtstestdata.customer1 indicates that the source table is customer1. If you set this parameter to Yes, all of the selected source tables in the task are merged into the destination table. If you do not need to merge specific source tables, you can create a separate data synchronization task for these tables. No is selected by default.
      Synchronization Type	Select the types of operations that you want to synchronize based on your business requirements. All operation types are selected by default.

   2. Select the objects to be synchronized.
      

      Setting

      Description

      Select the objects to be synchronized

      Select one or more tables from the Available section and click the icon to move the tables to the Selected section. Up to 64 tables can be migrated. After an object is synchronized to the destination instance, the name of the object remains unchanged. You can use the object name mapping feature to change the names of the objects that are synchronized to the destination instance. For more information, see Rename an object to be synchronized. Warning If you set Merge Multi Tables to Yes in Step 8 and select multiple source tables, you must use the object name mapping feature to change their names to the same table name in the Tablestore instance. Otherwise, data is inconsistent.

   3. Click Next.
5. Optional:In the Selected section, move the pointer over a table, and then click Edit. In the Edit Table dialog box, set the data type of each column in the Tablestore instance.
   
6. Configure the primary key columns of the tables that you want to synchronize to the Tablestore instance.
   

   Note For more information about primary keys of Tablestore instances, see Primary keys.