This topic describes how to migrate an ApsaraDB RDS for PostgreSQL instance across zones in the same region. After the migration is complete, the attributes, configuration, and endpoints of the RDS instance remain unchanged. The time that is required to complete the migration is based on the volume of data to be migrated. The migration can take a few hours.

Prerequisites

  • The RDS instance runs one of the following PostgreSQL versions and RDS editions:
    • PostgreSQL 10 on RDS High-availability Edition (with local SSDs)
    • PostgreSQL 9.4
  • The region where the RDS instance resides consists of multiple zones. For more information, see Regions and zones.

Billing

The migration is provided free of charge. This applies even if you migrate your RDS instance from one zone to multiple zones.

Precautions

  • During the migration, a transient connection error of about 30 seconds occurs. Make sure that your application is configured to automatically reconnect to your RDS instance.
  • After the migration, your RDS instance switches to a new VPC and a new vSwitch. In this case, the virtual IP addresses (VIPs) of your RDS instance change. Therefore, we recommend that you connect your application to your RDS instance by using an internal or public endpoint. Do not establish a connection by using an IP address.
  • The VIP changes temporarily interrupt the availability of DRDS . After the migration is completed, you must immediately update and view endpoints in the DRDS console.
  • If your RDS instance has an ongoing Data Transmission Service (DTS) task, you must restart the task after the migration is completed.

Migration scenarios

Migration scenario Description
Migration from one zone to another zone The original zone where your RDS instance resides cannot ensure service performance due to issues such as heavy loads.
Migration from one zone to multiple zones You want to implement disaster recovery across data centers for your RDS instance. After the migration is completed, your RDS instance and its secondary instance reside in different zones.

Multi-zone deployment delivers higher disaster recovery capabilities than single-zone deployment. If your RDS instance is deployed in a single zone, it can withstand server and rack failures. However, if your RDS instance is deployed in multiple zones, it can withstand data center failures.

Migration from multiple zones to one zone You want your RDS instance to provide specific features that are supported only for single-zone deployment.

Procedure

  1. Go to the Basic Information page.
    1. Log on to the ApsaraDB for RDS console. In the left-side navigation pane, click Instances. In the top navigation bar, select the region where your RDS instance resides.
      选择地域
    2. Find your RDS instance and click its ID.
  2. In the Basic Information section of the Basic Information page, click Migrate Across Zones.
  3. In the dialog box that appears, specify the destination primary zone, the vSwitch in the destination primary zone, and the switching time, and then click OK.

    After you click OK, ApsaraDB RDS starts to copy the data of your RDS instance to the destination primary zone. This does not interrupt the running of your RDS instance. After all the data is copied to the destination primary zone, ApsaraDB RDS switches over your workloads to the destination primary zone at the specified switching time. The switching time can be Migrate Immediately or Switch Within Maintenance Window.

    Note
    • During the switchover, a transient connection error of about 30 seconds occurs. Make sure that your application is configured to automatically reconnect to your RDS instance. Otherwise, you must manually reconnect your application to your RDS instance.
    • If the DNS records cached on the client are not immediately updated after the migration is completed, some of your workloads may be switched over to the destination primary zone 10 minutes later. This will cause another transient connection error.
    Migrate Instance Across Zones dialog box

Related operations

Operation Description
Migration zone Migrates an ApsaraDB RDS instance across zones in the same region.