:Configure a data synchronization task by using the new DTS console

Precautions

Preparations

• If the source or destination database is a self-managed database, you must deploy the network environment for the database. For more information, see Preparation overview.
• Make sure that the source and destination instances are created and the database engine versions are supported by DTS. For more information about the supported database engine versions, see Overview of data synchronization scenarios.

Procedure

1. Go to the Data Synchronization Tasks page.
   1. Log on to the DMS console.
   2. In the top navigation bar, click DTS.
   3. In the left-side navigation pane, choose DTS (DTS) > Data Synchronization.
   Note You can also go to the Data Synchronization Tasks page of the new DTS console.
2. From the drop-down list to the right of Data Synchronization Tasks, select the region in which your data synchronization instance resides.
   Note If you use the new DTS console, select the region in which your data synchronization instance resides in the top navigation bar.
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 in the upper part of the page. This helps you create and run the data synchronization task.

   Section	Parameter	Description
   N/A	Task Name	DTS automatically generates a task name. We recommend that you specify an informative name to identify the task. You do not need to use a unique task name.
   Source Database	Select Instance	Select whether to use an existing instance. If you select an existing instance, DTS automatically applies the parameter settings of the instance. You do not need to configure the corresponding parameters again. If you do not use an existing instance, you must configure parameters for the source database.
   	Database Type	Select MySQL.
   	Access Method	Select Alibaba Cloud Instance.
   	Instance Region	Select the region in which the source ApsaraDB RDS for MySQL instance resides.
   	Replicate Data Across Alibaba Cloud Accounts	Specify whether to synchronize data across Alibaba Cloud accounts. In this example, No is selected.
   	RDS Instance ID	Select the ID of the source ApsaraDB RDS for MySQL instance.
   	Database Account	Enter the database account of the source ApsaraDB RDS for MySQL instance. The account must have the SELECT permissions on the objects to be synchronized and the REPLICATION CLIENT and REPLICATION SLAVE permissions.
   	Database Password	The password of the database account.
   	Encryption	Specifies whether to encrypt the connection to the database. You can select Non-encrypted or SSL-encrypted based on your business requirements. If you want to select SSL-encrypted, you must enable SSL encryption for the ApsaraDB RDS for MySQL instance before you configure the data synchronization task. For more information, see Configure SSL encryption for an ApsaraDB RDS for MySQL instance.
   Destination Database	Select Instance	Select whether to use an existing instance. If you select an existing instance, DTS automatically applies the parameter settings of the instance. You do not need to configure the corresponding parameters again. If you do not use an existing instance, you must configure parameters for the source database.
   	Database Type	Select MySQL.
   	Access Method	Select Alibaba Cloud Instance.
   	Instance Region	Select the region in which the destination ApsaraDB RDS for MySQL instance resides.
   	Instance ID	Select the ID of the destination ApsaraDB RDS for MySQL instance.
   	Database Account	Enter the database account of the destination ApsaraDB RDS for MySQL instance. The account must have the read and write permissions on the destination database.
   	Database Password	The password of the database account.

4. In the lower part of the page, click Test Connectivity and Proceed.
   Note

   • If the source or destination database is an Alibaba Cloud database instance, such as an ApsaraDB RDS for MySQL or ApsaraDB for MongoDB instance, DTS automatically adds the CIDR blocks of DTS servers to the whitelist of the instance. If the source or destination database is a self-managed database hosted on an Elastic Compute Service (ECS) instance, DTS automatically adds the CIDR blocks of DTS servers to the security group rules of the ECS instance. 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 that is deployed in a data center or provided by a third-party cloud service provider, you must manually add the CIDR blocks of DTS servers to the whitelist of the database to allow DTS to access the database.
   • After data synchronization is complete, we recommend that you remove the CIDR blocks of DTS servers from the allowlists or security groups. You must remove the IP address whitelist group whose name contains dts from the whitelist of the ApsaraDB instance or the security rules of the ECS instance. For more information about the CIDR blocks that you must remove from the whitelist of the self-managed databases that are deployed in data centers or databases that are hosted on third-party cloud services, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.
5. Select objects for the task and configure advanced settings.
   • Basic Settings

     Parameter	Description
     Synchronization Types	By default, Incremental Data Synchronization is selected. You must also select Schema Synchronization and Full Data Synchronization. After the precheck is complete, DTS synchronizes the historical data of the selected objects from the source database to the destination database. The historical data is the basis for subsequent incremental synchronization.
     Processing Mode of Conflicting Tables	Precheck and Report Errors: checks whether the destination cluster 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 identical table names, the precheck is passed. Otherwise, an error is returned during the precheck and the data synchronization task cannot be started. Note You can use the object name mapping feature to rename the tables that are synchronized to the destination database. You can use this feature if the source and destination databases contain identical table 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 schemas, and a data record has the same primary key value as an existing data record in the destination database: During full data synchronization, DTS does not synchronize the data record to the destination database. The existing data record in the destination database is retained. During incremental data synchronization, DTS synchronizes the data record to the destination database. The existing data record in the destination database is overwritten. If the source and destination databases have different schemas, data may fail to be initialized. In this case, only some columns are synchronized or the data synchronization 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.
     Selected Objects	To rename an object that you want to synchronize 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 To select the SQL operations performed on a specific database or table, right-click an object in the Selected Objects section. In the dialog box that appears, select the SQL operations that you want to synchronize. 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 configure alerting for the data synchronization task. If the task fails or the synchronization latency exceeds the specified threshold, alert contacts will receive notifications. Valid values: No: does not configure alerting. Yes: configures alerting. If you select Yes, you must also specify the alert threshold and alert contacts. For more information, see Configure monitoring and alerting when you create a DTS task.
     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 synchronize temporary tables generated by online DDL operations. Valid values: Yes: DTS synchronizes the data of temporary tables generated by online DDL operations. Note If online DDL operations generate a large amount of data, the data synchronization task may take an extended period of time to complete. No: DTS does not synchronize the data of temporary tables generated by online DDL operations. Only the original DDL data of the source database is synchronized. Note If you select No, the tables in the destination database may be locked. Note This parameter is available only when the source database is a self-managed MySQL database, an ApsaraDB RDS for MySQL instance, or a PolarDB for MySQL cluster.
     Retry Time for Failed Connection	The retry time range for failed connections. If the source or destination database fails to be connected after the data synchronization 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 synchronization task. Otherwise, the data synchronization task fails. Note If you set different retry time ranges for multiple DTS 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 the earliest opportunity after the source and destination instances are released.
     Configure ETL	Specifies whether to configure the extract, transform, and load (ETL) feature. For more information, see What is ETL? Valid values: 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. Click Next: Save Task Settings and Precheck in the lower part of the page.
   Note

   • Before you can start the data synchronization task, DTS performs a precheck. You can start the data synchronization 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 analyze the causes based on the check results, troubleshoot the issues. Then, run a precheck again.
   • If an alert is generated for an item during the precheck, perform the following operations based on the scenario:
     • In scenarios where you cannot ignore the alert item, click View Details next to the failed item. After you analyze the causes based on the check results, troubleshoot the issues. Then, run a precheck again.
     • In scenarios where you can ignore the alert item, click Confirm Alert Details next to the failed item. 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.
7. Wait until the success rate becomes 100%. Then, click Next: Purchase Instance.
8. On the Purchase Instance page, configure the Billing Method and Instance Class parameters for the data synchronization instance. The following table describes the parameters.

   Section	Parameter	Description
   New Instance Class	Billing Method	Subscription: You pay for the instance when you create an instance. The subscription billing method is more cost-effective than the pay-as-you-go billing method for long-term use. Pay-as-you-go: A pay-as-you-go instance is charged on an hourly basis. The pay-as-you-go billing method is suitable for short-term use. If you no longer require a pay-as-you-go instance, you can release the pay-as-you-go instance to reduce costs.
   	Instance Class	DTS provides several instance classes that have different performance in synchronization speed. You can select an instance class based on your business scenario. For more information, see Specifications of data synchronization instances.
   	Subscription Duration	If you select the subscription billing method, set the subscription duration and the number of instances that you want to create. The subscription duration can be one to nine months or one to three years. Note This parameter is displayed only if you select the subscription billing method.

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