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Real-time synchronization between on-premises and Apsara databases

Last Updated: May 13, 2018

The incremental migration function of DTS has now lifted the 15 day restriction, so the incremental migration function can be used to achieve real-time data synchronization between on-premises databases and ApsaraDB RDS.

Data source requirement

The on-premises databases must be MySQL, SQL Server, PostgreSQL, or MongoDB.


Before configuring synchronization, make sure the target instance exists. Otherwise, buy an instance on the RDS or MongoDB console.

Configuration procedure

The following example describes how to configure the synchronization between on-premises MySQL and ApsaraDB RDS for MySQL.

  1. Log in to the DTS Console and click Create migration task at the upper right corner.

  2. Configure source and target instance information.

    • Task name

      A name indicating specific services of the task is recommended.

    • Source database

      • Instance type: Select On-premises databases.
      • Instance region: Select the region closest to the source instance.
      • Database type: Select MySQL.
      • Host name or IP address: Enter the address of the on-premises MySQL instance. If the on-premises MySQL instances adopt the active/standby architecture with a DNS address, it is recommended you fill in the DNS address so that the synchronization is not interrupted in case of an active/standby switchover.
      • Port: Enter the listening port of the on-premises MySQL instance.
      • Database account: Enter the username of the account of the on-premises MySQL instance.
      • Database password: Enter the password of the account of the on-premises MySQL instance.
    • Target database

      • Instance type: Select RDS instance.
      • RDS instance ID: Enter the target RDS instance ID of the synchronization link. This RDS instance cannot be a disaster recovery or read-only instance.
      • Database account: Enter the user name of the read/write account of the target RDS instance.
      • Database password: Enter the password of the read/write account of the target RDS instance.


  3. Update the IP address whitelist of the RDS instance.

    After configuring the connection information, click Authorize whitelist and enter into next step at the lower right corner. This adds the DTS server IP address to the IP address whitelist of the target RDS instance; otherwise, the synchronization will fail because the DTS server cannot access the target RDS instance.

  4. Select the objects to be synchronized.

    • Migration types

      Select all of the three migration types: Migrate object structure, Migrate existing data, Replicate data changes

      • Migrate object structure and Migrate existing data migrate all existing data
      • Replicate data changes synchronizes the data changes made to the source instance during the migration to the target instance, so that eventually the source instance is dynamically synchronous with the target instance.
    • Objects to be migrated

      Select the databases or tables to be synchronized and add them to the selected object list on the right.

  5. Start the pre-check.

    Click Pre-check and start at the lower right corner.

    If the pre-check fails, click Failed next to the failure items, solve the problem, and perform the pre-check again.

  6. Purchase the synchronization link.

    Set the following parameters, select the service terms, and click Buy and start now.

    • Instance region

      To improve synchronization performance, DTS automatically sets the link instance region to be the region where the target instance resides.

    • Instance specification

      The specification of the synchronization link affects the synchronization performance. The default specification is Medium.