PolarDB:Orca data migration (DTS)

Connection

• Only the VPN Gateway connection type is supported for Orca, whether it is the source or destination. Other connection types (such as Cloud Instance) will fail at the connection test step.

• Two-way synchronization via DTS is not supported.

Migration type

• When Orca is the source, only full migration is available. Incremental data migration is not supported.

Redis version

• When Orca is the source: the destination Redis version must be compatible with the Redis versions Orca supports. Incompatible versions cause errors during migration.

• When a Redis instance is the source: its version must not be later than Redis 7.0 and not earlier than version 2.8.0. Versions outside this range cannot be migrated to Orca.

Database

• Orca supports only DB0. Data in DB1 through DB255 cannot be migrated to Orca.

Step 1: Configure the source and destination databases

1. Log on to the DTS console and click Create Task.DTS Data Migration page

2. Configure the task name.

   Parameter	Description
   Task Name	DTS generates a name automatically. Enter a descriptive name for easy identification. The name does not need to be unique.

   

3. Configure the source database.

   Note

   If the source database is hosted on a third-party cloud platform, complete the required preparations first.

   Parameter	Value
   Database Type	NoSQL Database > Tair/Redis
   Connection Type	Cloud Instance
   Instance Region	Select the region where the Tair (Redis-compatible) instance resides.
   Cross-account	No (if the source and destination are in the same account). For cross-account migration, see Migrate data across Alibaba Cloud accounts.
   Instance ID	Select the Tair (Redis-compatible) instance.
   Authentication Method	Password Logon
   Database Password	Enter the password of the Tair (Redis-compatible) instance.
   Connection Method	Select Non-encrypted or SSL-encrypted based on the instance configuration.

4. Configure the destination database.

   Parameter	Value
   Database Type	NoSQL Database > Tair/Redis
   Connection Type	Leased Line/VPN Gateway/Smart Access Gateway
   Instance Region	Select the region where the PolarDB cluster resides.
   VPC Connected to Destination Database	Select the VPC of the PolarDB cluster.
   Instance Mode	Basic Edition (Cluster Edition is not supported)
   Domain Name or IP Address	Enter the Orca private endpoint.
   Port	Enter the Orca private endpoint port. Default: 6379.
   Authentication Method	Account And Password Logon
   Database Password	Enter the Orca account and password.
   Connection Method	Select Non-encrypted or SSL-encrypted based on the PolarDB cluster configuration.
   Primary/Standby vSwitch for VPC Data Channel	Select the vSwitches for the VPC data channel that DTS uses to access your data source.

   

5. Click Test Connection And Proceed. In the Authorize DTS Servers To Access dialog box, add the DTS server IP addresses listed under Destination to the PolarDB cluster whitelist, then click Test Connection. If the connection test passes, DTS automatically proceeds to the task object configuration page.

   Warning

   Adding DTS server CIDR blocks to your database whitelist or ECS security group rules introduces security risks. Before proceeding, take preventive measures such as: strengthening your credentials, restricting exposed ports, authenticating API calls, auditing whitelist rules regularly, and connecting through Express Connect, VPN Gateway, or Smart Access Gateway.

   

Step 2: Configure the migration object

1. Configure the following settings.

   Parameter	Options	Description
   Migration Types	Full Migration, Incremental Migration, or both	Select both for minimal-downtime migration. If you select Full Migration only, do not write new data to the source instance during migration.
   Processing Mode for Existing Destination Tables	Precheck and Report Errors	Checks whether the destination database is empty. The task fails the precheck if the destination is not empty.
   	Ignore Errors and Proceed	Skips the Check the existence of objects in the destination database check. Data with matching keys in the source overwrites data in the destination, which may cause data loss.
   Migration Objects	Select from Source Objects and move to Selected Objects using the icon.	Select at the database level. Select 0 (DB0) — Orca supports only DB0.

   

2. Click Next: Advanced Settings and configure as needed.

3. Click Next: Data Verification and configure as needed.

Step 3: Precheck

Click Next: Save Task And Precheck and wait for the precheck to complete.

To use data verification, see Configure data verification before clicking Next: Save Task And Precheck.

Step 4: Purchase and start

1. In the Confirm Settings dialog box, set the Channel Specification.

2. Read and accept the Data Transmission Service (Pay-as-you-go) Service Terms, then click Purchase And Start.

3. Wait for migration to complete.

   • Full migration: The task stops automatically. Do not stop it manually — doing so may leave the migrated data incomplete.

   • Incremental migration: The task does not stop automatically. Stop it manually at an appropriate time, such as during off-peak hours or before switching workloads to the destination. To stop an incremental migration task with zero data loss:

     1. When the task status shows Incremental Migration and latency shows No Latency, stop writing to the source database for a few minutes. At this point, the Incremental Migration status may show a latency.

     2. Wait until the Incremental Migration status changes to No Latency.

     3. Manually stop the task.