Move an ApsaraDB for MyBase instance to a different host within your dedicated cluster — in the same zone or across zones — to rebalance workloads or respond to host issues.
Migration disconnects the instance for approximately 30 seconds. Schedule the operation during low-traffic periods, or use the Maintenance Window option to defer it to a predictable off-peak window.
Prerequisites
Before you begin, ensure that you have:
An ApsaraDB MyBase for MySQL, ApsaraDB MyBase for SQL Server, or ApsaraDB MyBase for PostgreSQL instance
Migration restrictions
| Instance type | Same-zone migration | Cross-zone migration |
|---|---|---|
| ApsaraDB MyBase for MySQL Master-replica Edition | Supported | Not supported |
| ApsaraDB MyBase for SQL Server | Supported | Not supported |
| ApsaraDB MyBase for MySQL High-availability Edition | Supported | Supported |
| ApsaraDB MyBase for PostgreSQL | Supported | Supported |
Cross-zone migration risks
If you migrate to a host in a different zone, address the following before and after migration:
VIP change: The virtual IP address (VIP) of the instance changes after migration. Connect your application using the instance endpoint, not the IP address, to avoid connection failures.
Client cache: If your client cache is full, data cannot be written to it. Clear the cache before migrating.
DTS tasks: If a Data Transmission Service (DTS) task is running on the instance, restart the DTS task after migration completes.
Migrate an instance
Log on to the ApsaraDB for MyBase console.
In the upper-left corner, select a region.
In the left-side navigation pane, click Dedicated Clusters. Find the dedicated cluster that contains the instance you want to migrate, then click Details in the Actions column.
In the left-side navigation pane, click Instances.
Find the instance, then choose More > Migrate in the Actions column.
In the panel that appears, configure the following parameters.
You can migrate a primary or secondary instance independently. To migrate only a primary instance, configure only the parameters for the primary instance.
Parameter Description Destination Zone The zone to migrate the instance to. The drop-down list shows all zones where hosts in the dedicated cluster are deployed. NoteAvailable only for ApsaraDB MyBase for MySQL High-availability Edition and ApsaraDB MyBase for PostgreSQL instances.
vSwitch The vSwitch for the destination zone. If no vSwitch is available, click Create vSwitch to create one. NoteAvailable only when migrating a primary instance to a different zone.
Destination Host The target host. If left blank, the instance is migrated to any available host in the specified zone. Migration Time When to perform the migration: Immediate — starts migration right away; use for urgent moves or off-peak hours when you can accept the 30-second disconnection immediately. Maintenance Window 02:00–06:00 — defers migration to the next maintenance window; use for routine migrations where a predictable low-traffic window exists. Specified Time — schedules migration at an exact time; use when you need precise control over when the disconnection occurs. 
Click OK.
Next steps
For database engine-specific migration steps and additional options, see: