Data Transmission Service (DTS) provides an easy-to-use data synchronization feature. To configure a data synchronization task, you only need to perform simple operations in the DTS console.
This topic provides a general procedure for configuring a data synchronization task. The procedure varies with the source and destination databases.
Before you begin
- 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 versions are supported by DTS.
- Log on to the DTS console.
- In the left-side navigation pane, click Data Synchronization.
- At the top of the Synchronization Tasks page, select the region where the destination instance resides.
- In the upper-right corner of the page, click New Console.
- On the Create Task page, 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 ensures that you can create and run the data synchronization task.
- In the lower part of the page, click Test Connectivity and Proceed.
- Select objects for the task and configure advanced settings.
- Basic Settings
Parameter Description Task Stages
By default, you must select both Schema Synchronization and Full Data Synchronization. After the precheck, DTS synchronizes the historical data of the selected objects from the source instance to the destination cluster. The historical data is the basis for subsequent incremental synchronization.
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
identical table names, the precheck is passed. Otherwise, an error is returned during
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 Rename an object to be synchronized.
- 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 guaranteed and your business may be exposed to potential risks.
- If the source and destination databases have the same schema, DTS does not synchronize data records that have the same primary keys as data records in the destination database.
- 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.
Select one or more objects from the Source Objects section and click the icon to move the objects to the Selected Objects section.
Rename Databases and Tables
- 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 Rename an object to be synchronized.
- To rename multiple objects at a time, click in the upper-right corner of the Selected Objects section. For more information, see Rename an object to be synchronized.
You can specify WHERE conditions to filter data. For more information, see Use SQL conditions to filter data.
Select the SQL operations to be synchronized In the Selected Objects section, right-click an object. In the dialog box that appears, select the DML and DDL operations that you want to synchronize.
- 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 identical table names, the precheck is passed. Otherwise, an error is returned during precheck and the data synchronization task cannot be started.
- Advanced Settings
Parameter Description Set AlertsSpecify whether to set alerts for the data synchronization task. If the task fails or the synchronization latency exceeds the threshold, the alert contacts will receive notifications.
- Select No if you do not want to set alerts.
- Select Yes to set alerts. In this case, you must also set the alert threshold and alert contacts.
Replicate Temporary Tables When DMS Performs DDL OperationsIf you use Data Management (DMS) to perform online DDL operations on the source database, you can specify whether to synchronize temporary tables generated by online DDL operations.
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.
- 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 be delayed.
- 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.
Retry Time for Failed ConnectionsSpecify the retry time for failed connections. Valid values: 10 to 1440. Unit: minutes. Default value: 120. We recommend that you set the retry time to more than 30 minutes. If DTS reconnects to the source and destination databases within the specified time, DTS resumes the data synchronization task. Otherwise, the data synchronization task fails.Note
- If multiple DTS instances have the same source or destination database, the lowest value takes effect. For example, the retry time is set to 30 minutes for Instance A and 60 minutes for Instance B, DTS retries failed connections at an interval of 30 minutes.
- When DTS retries a connection, you are charged for the DTS instance. We recommend that you specify the retry time based on your business needs. You can also release the DTS instance at your earliest opportunity after the source and destination instances are released.
- Basic Settings
- 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, 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.
- Wait until the Success Rate becomes 100%. Then, click Next: Purchase Instance.
- On the Purchase Instance page, specify the Billing Method and Instance Class parameters for the data synchronization
instance. The following table describes the parameters.
Section Parameter Description Parameters Billing Method
- Subscription: You can pay for your subscription when you create an instance. We recommend that you select the subscription billing method for long-term use because it is more cost-effective than the pay-as-you-go billing method. You can save more costs with longer subscription periods.
- Pay-as-you-go: A pay-as-you-go instance is billed on an hourly basis. We recommend that you select the pay-as-you-go billing method for short-term use. If you no longer require your pay-as-you-go instance, you can release it 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 channels. Subscription Length If you select the subscription billing method, set the subscription length and the number of instances that you want to create. The subscription length can be one to nine months or one to three yearsNote This parameter is available only if you select the subscription billing method.
- Read and select Data Transmission Service (Pay-as-you-go) Service Terms.
- Click Buy and Start to start the data synchronization task. You can view the progress of the task in the task list.