Data Transmission Service (DTS) supports data synchronization from MySQL databases to Oracle databases.

Supported source and destination databases

The following table describes the types of source and destination databases that are supported for data synchronization from MySQL databases to Oracle databases. This topic describes the configurations of this type of data synchronization. In this example, data is synchronized from an ApsaraDB RDS for MySQL instance to a self-managed Oracle database hosted on Elastic Compute Service (ECS). The procedures for configuring data synchronization from and to other types of databases are similar.
Source database Destination database
  • ApsaraDB RDS for MySQL instance
  • Self-managed database that is hosted on Elastic Compute Service (ECS)
  • Self-managed database that is connected over Express Connect, VPN Gateway, or Smart Access Gateway
  • Self-managed database that is connected over Database Gateway
  • Self-managed database that is connected over Cloud Enterprise Network (CEN)
  • Self-managed database that is connected over Express Connect, VPN Gateway, or Smart Access Gateway
  • Self-managed database that is hosted on ECS
  • Self-managed database that is connected over Database Gateway
  • Self-managed database that is connected over Cloud Enterprise Network (CEN)

Prerequisites

Usage notes

Supported synchronization modes

  • One-way one-to-one synchronization
  • One-way one-to-many synchronization
  • One-way many-to-one synchronization

SQL operations that can be synchronized

Type Operation
DML INSERT, UPDATE, and DELETE
DDL
  • CREATE TABLE, ALTER TABLE, DROP TABLE, RENAME TABLE, and TRUNCATE TABLE
  • ADD COLUMN, DROP COLUMN, MODIFY COLUMN, and RENAME COLUMN
  • CREATE INDEX, UNIQUE INDEX, and DROP INDEX

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.
  2. On the right side of Data Synchronization Tasks, select the region where the data synchronization instance resides.
    Note If you use the new DTS console, you must select the region where the data synchronization instance resides in the top navigation bar.
  3. Click Create Task. On the page that appears, configure the source and destination databases.
    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 Database Type Select MySQL.
    Access Method Select Alibaba Cloud Instance.
    Instance Region The region in which the source ApsaraDB RDS for MySQL instance resides.
    Replicate Data Across Alibaba Cloud Accounts In this example, No is selected because data is synchronized within the same Alibaba Cloud account.
    RDS Instance ID Select the ID of the source ApsaraDB RDS for MySQL instance.
    Database Account Enter the username that is used to connect to the source database in the ApsaraDB RDS for MySQL instance.
    Database Password

    Enter the password of the database account.

    Encryption

    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 Database Type Select Oracle.
    Access Method Select Self-managed Database on ECS.
    Instance Region Select the region in which the destination Oracle database resides.
    ECS Instance ID Select the ID of the ECS instance that hosts the destination Oracle database.
    Port Number Enter the service port number of the destination Oracle database. The default port number is 1521.
    Oracle Type
    • If you select Non-RAC Instance, you must specify the SID parameter.
    • If you select RAC or PDB Instance, you must set the Service Name parameter.
    Database Account The username that is used to connect to the destination Oracle database.
    Database Password

    Enter the password of the database account.

  4. In the lower part of the page, click Test Connectivity and Proceed.
    Note
    • You do not need to modify the security settings for ApsaraDB instances (such as ApsaraDB RDS for MySQL and ApsaraDB for MongoDB) and ECS-hosted databases. DTS automatically adds the CIDR blocks of DTS servers to the whitelists of ApsaraDB instances or the security group rules of Elastic Compute Service (ECS) instances. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.
    • After data synchronization is completed, we recommend that you remove the CIDR blocks of DTS servers from the whitelists or security groups.
  5. Select objects for the task and configure advanced settings.
    • Basic Settings
      Parameter Description
      Task Stages

      Incremental Data Synchronization is selected by default. You must also select Schema Synchronization and Full Data Synchronization. After the precheck is completed, DTS synchronizes the historical data of selected objects from the source database 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 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 consistency is not guaranteed and your business may be exposed to potential risks.
        • If the source and destination databases have the same schema, and a data record has the same primary key 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.
      Capitalization of Object Names in Destination Instance

      Specify 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 make sure that the capitalization of object names is consistent with that of 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 and click the Rightwards arrow icon to add the objects to the Selected Objects section.

      Note You can select columns, tables, or databases as the objects to be synchronized. If you select tables or columns as the objects to be synchronized, DTS does not synchronize other objects such as views, triggers, and stored procedures to the destination database.
      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.
    • Advanced Settings
      Parameter Description
      Set Alerts
      Specify 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.
      Retry Time for Failed Connection
      Specify the retry time range for failed connections. If a data synchronization task is disconnected, DTS immediately retries a connection within the specified time range. Valid values: 10 to 1440. Unit: minutes. Default value: 120. 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 synchronization task. Otherwise, the data synchronization task fails.
      Note
      • If multiple DTS instances have the same source or destination database, the lowest value of this parameter takes effect. For example, the retry time range is set to 30 minutes for Instance A and 60 minutes for Instance B, DTS retries failed connections within 30 minutes.
      • 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.
      Configure ETL
      Specify whether you want to enable the ETL feature. For more information, see What is ETL?.
      • If you select Yes, the ETL feature is enabled. You must specify a policy in the text box.
      • If you select No, the ETL feature is disabled.
  6. In the lower part of the page, click Next: Save Task Settings and Precheck.
    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 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.
  7. Wait until the Success Rate becomes 100%. Then, click Next: Purchase Instance.
  8. 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 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 a pay-as-you-go instance, you can release the 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 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 years.
    Note This parameter is available only if you select the subscription billing method.
  9. Read and select 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.