Migrate data between ApsaraDB RDS for PostgreSQL instances across different accounts

1a. Create a CEN instance

1. Log on to the CEN console.

2. On the Instances page, click Create CEN Instance.

3. In the Create CEN Instance dialog box, configure the following parameters and click OK.

   Parameter	Description
   Name	Enter a name for the CEN instance. The name must be 2–128 characters in length, can contain digits, hyphens (-), and underscores (_), and must start with a letter.
   Description	(Optional) Enter a description. The description must be 2–256 characters in length and cannot start with http:// or https://.

1b. Add VPCs to the CEN instance

Add both VPCs separately — the source VPC (in Account A) and the destination VPC (in Account B). The steps below describe how to add the source VPC. Repeat the process for the destination VPC, setting Region and Network Instance to the destination instance values and Resource Ownership to Same Account.

1. On the Instances page, click the ID of the CEN instance you created.

2. On the Basic Information tab, click the icon to the right of the VPC count.

3. On the Connect Network Instance page, configure the following parameters and click Create.

   Parameter	Description
   Instance type	The default value is Virtual Private Cloud (VPC).
   Region	Select the region where the source instance resides.
   Transit router	If no transit router exists in the region, the system creates one automatically. Select a primary zone and a secondary zone for the transit router.
   Resource ownership	Select Cross-account and enter the UID of Account A. To view the UID, click the user icon in the menu bar.
   Connection name	Enter a custom name.
   Network instance	Select the VPC of the source instance. You can view the VPC ID on the Database Connection page in the ApsaraDB RDS console. After selecting the VPC, choose the vSwitches that correspond to the primary and secondary zones of the transit router.

After adding both VPCs, the result appears as follows:

1c. (Optional) Purchase a cross-region bandwidth plan

Perform this step only if the source and destination instances are in different regions — for example, if the source is in China (Beijing) and the destination is in China (Hangzhou). If both instances are in the same region, skip to Step 2.

1. On the Instances page, click the ID of the CEN instance you created.

2. On the Basic Information tab, click Bandwidth Plans, then click Purchase Bandwidth Plan (Subscription).

3. Configure the following parameters and click Buy Now. Complete the payment.

   Parameter	Description
   CEN ID	Retain the displayed CEN instance. After purchase, the bandwidth plan is automatically associated with the CEN instance.
   Area A	Select one area for cross-region communication. In this example, select Mainland China. The area cannot be changed after purchase.
   Area B	Select the other area for cross-region communication. In this example, select Mainland China.
   Billing method	Retain the default value Pay-By-Bandwidth.
   Bandwidth	Specify the bandwidth in Mbit/s.
   Bandwidth package name	Enter a name for the bandwidth plan.
   Order time	Select a subscription duration. Optionally enable auto-renewal.

After purchase, the result appears as follows:

1d. (Optional) Set the cross-region bandwidth

Perform this step only if the source and destination instances are in different regions. If both instances are in the same region, skip to Step 2.

1. On the Instances page, click the ID of the CEN instance you created.

2. On the Basic Information tab, click Bandwidth Plans, then click Allocate Bandwidth for Inter-region Communication.

3. On the Connection with Peer Network Instance page, configure the following parameters and click OK.

   Parameter	Description
   Instance type	Select Inter-region Connection.
   Region	Select the region where the source RDS instance resides. In this example, select China (Beijing).
   Transit router	CEN automatically identifies the transit router in the source region.
   Peer region	Select the region where the destination RDS instance resides. In this example, select China (Hangzhou).
   Transit router	CEN automatically identifies the transit router in the destination region.
   Bandwidth allocation mode	Select Allocate from Bandwidth Plan or Pay-By-Data-Transfer. In this example, select Allocate from Bandwidth Plan.
   Bandwidth plan	Select a bandwidth plan associated with the CEN instance. Required only when Bandwidth allocation mode is set to Allocate from Bandwidth Plan.
   Bandwidth	Enter the bandwidth in Mbit/s.
   Default line type	Select Platinum or Gold. Platinum is available only when Bandwidth allocation mode is set to Pay-By-Data-Transfer.

After configuration, the result appears as follows:

2a. Add an IP whitelist entry

Add the destination VPC's CIDR block to the source instance's IP whitelist so that the destination instance can connect to the source.

To find the destination VPC's CIDR block:

1. Log on to the ApsaraDB RDS console and go to the Instances page. Select the region where the destination instance resides, find the instance, and click its ID.

2. In the left-side navigation pane, click Database Connection. Check the Network Type field to get the VPC CIDR block.

After getting the CIDR block, add it to the source instance's IP whitelist. For details, see Configure an IP address whitelist.

2b. Create a privileged account

Create a privileged account on the source instance for the migration. The account must have the CREATE ROLE, REPLICATION, and pg_monitor permissions.

If a privileged account already exists on the source instance, skip this step.

For details, see Create an account. Set Account Type to Privileged Account.

3a. Run a cloud migration assessment

Run a feasibility assessment to verify that the source instance meets migration requirements before migrating data.

1. Log on to the ApsaraDB RDS console and go to the Instances page. Select the region where the destination instance resides, find the instance, and click its ID.

2. In the left-side navigation pane, click Cloud Migration/DR Construction, then click the Feasibility assessment tab.

3. In the Configure Scenario and Source Type step, set Scenario to Migration to Cloud and Source to ApsaraDB RDS Instance. Click Next.

4. In the Configure Destination Instance step, click Next.

5. In the Configure Source Instance step, select all items and click Next. Complete all listed preparation tasks before starting the migration.

6. In the Start Feasibility Assessment step, enter the source instance information.

   Parameter	Description
   Migration task name	Auto-generated by ApsaraDB RDS. No modification needed.
   Source VPC/DNS IP	Enter the internal endpoint of the source RDS instance. See View and change the endpoints and port numbers.
   Port of Source Instance	Enter the internal port number of the source RDS instance. See View and change the endpoints and port numbers.
   Username	Enter the username of the privileged account on the source instance.
   Password	Enter the password of the privileged account.

7. Click Create Feasibility Assessment Task.

   During the assessment, the destination instance status changes to Maintaining Instance.

After the assessment completes, view the result in the Migration to Cloud section of the Feasibility assessment tab:

• Successful: Proceed to the next step.

• Failed: Click View Report in the Actions column to view and resolve errors. For common errors, see Introduction to cloud migration assessment reports.

3b. Start the cloud migration task

1. In the left-side navigation pane, click Cloud Migration/DR Construction, then click the Migration to Cloud tab. Click Create Cloud Migration Task.

2. In the Create Cloud Migration Task dialog box, select the assessment task with a Successful status from the Associated Assessment Task drop-down list.

   ApsaraDB RDS automatically fills in Migration Source Type, Source IP/DNS, Source Port, and Username based on the selected assessment task. No manual configuration is needed.

3. Click Initiate Migration to Cloud. ApsaraDB RDS starts the cloud migration task automatically.

   Important

   During migration, the destination instance status changes to Migrating Data In. The source instance remains readable and writable. Do not migrate data from or to the source instance, restart the source instance, or change its specifications during this time.

3c. Switch workloads to the destination instance

1. Click the link in the Cloud Migration Phase column to monitor the task progress.

2. When the task enters the incremental data synchronization phase, click the switchover button in the Actions column.

3. In the Switchover dialog box, stop writes to the source instance using one of the following methods:

   • Stop application writes: Configure your application to stop writing data to the source instance.

   • Set the source instance to read-only:

     1. Change the rds_force_trans_ro_non_sup parameter to on. See Modify the parameters of an ApsaraDB RDS for PostgreSQL instance.

     2. Run the following statement to terminate all existing sessions:

        SELECT pg_terminate_backend(pid) FROM pg_stat_activity
        WHERE usename not in ('replicator', 'monitor', 'pgsql', 'aurora') AND pid != pg_backend_pid();

4. Select all check boxes and click Switch Now. Wait for the migration to complete.