This topic describes how to migrate an ApsaraDB RDS for SQL Server instance across zones in the same region. The attributes, configurations, and endpoints of the instance remain unchanged after the migration. The amount of time it takes to complete the migration depends on the volume of data. Typically, it takes several hours to complete the migration.

Migration types

Migration type Scenario
Migration from one zone to another The original zone to which the RDS instance belongs cannot ensure high performance due to heavy loads or other issues.
Migration from one zone to multiple zones You require the RDS instance to provide disaster recovery across data centers. After the migration, your primary and secondary instances are located in different zones.

Multi-zone deployment delivers higher disaster recovery capabilities than single-zone deployment. For example, single-zone instances can tolerate faults on the server or rack scale, whereas multi-zone instances can withstand faults on the data center scale.

Migration from multiple zones to one zone The features that you need require single-zone deployment.

Billing

Migration can be performed free of charge, even if you migrate your RDS instance from one zone to multiple zones.

Prerequisites

  • The instance runs SQL Server 2008 R2 with local SSDs.
  • The region where the instance resides contains multiple zones. For more information about regions and zones, see Regions and zones.

Precautions

Services may be disconnected for 30 seconds during cross-zone migration, and most operations related to databases, accounts, and networks cannot be performed. Therefore, make sure that your applications are configured with automatic reconnection policies and schedule your instance migration during off-peak hours.

Procedure

  1. Log on to the ApsaraDB for RDS console.
  2. In the upper-left corner of the page, select the region where the instance resides.Select a region
  3. Find the target RDS instance and click the instance ID.
  4. In the upper-right corner of the Basic Information page, click Migrate Across Zones.
  5. In the dialog box that appears, select the destination zone, VSwitch, and migration time, and then click OK.

    After you click OK, the system copies data to the destination zone while the instance runs normally. After data is copied, services are switched over to the new connection at the specified time (Switch Now or Switch Within Maintenance Window).

    Note
    • Services are disconnected for 30 seconds during switchover. Make sure that your applications are configured with automatic reconnection policies. Otherwise, you must manually reconnect your applications to RDS.
    • Some services may take longer than 10 minutes to switch over because the DNS cache is not immediately flushed, which causes a disconnection again.
    • If you want to change the maintenance window, follow these steps:
      1. Click Modify.
      2. In the Configuration Information section, select a maintenance window and click Save.
      3. Refresh the Basic Information page and perform Step 5.

Related operations

Operation Description
MigrateToOtherZone Migrates an RDS instance from one zone to another.