Enable cross-region disaster recovery for RDS for PostgreSQL through Global Active Database (GAD) instance groups. Learn how to validate instance requirements, create groups, and safely delete them.
Prerequisites
To create a GAD instance group, you must designate an existing RDS for PostgreSQL instance to serve as the primary node. This instance must satisfy the following specifications:
Billing method: Subscription or pay-as-you-go.
RDS edition: Basic Edition or High-availability Edition.
Engine version: PostgreSQL 11 or higher.
Instance types:
Dedicated: 4 cores and 8 GB of memory or higher.
General-purpose: 2 cores and 4 GB of memory or higher.
Region: China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Shenzhen), China (Hohhot), China (Heyuan), and China (Chengdu).
If you are configuring GAD for the first time, you must authorize the Data Transmission Service (DTS) to access cloud resources before proceeding.
Topology constraints
Instance exclusivity: An RDS for PostgreSQL instance can belong to only one GAD instance group. This restriction applies regardless of whether the instance serves as a primary or secondary node.
Group structure: Each GAD instance group supports a strict 1:1 topology (one primary node and one secondary node).
Billing
GAD costs are derived from the underlying resources - the RDS instances and the Data Transmission Service (DTS) synchronization link. Standard subscription or pay-as-you-go rates apply to both the primary and secondary nodes, with no additional surcharges for incorporating existing instances. For more information, see Billing.
Create an instance group
From Global Active Database page
Go to the Global Active Database page. Click Create Instance Group.
On the Create Global Active Instance Group page, configure the following parameters:
Parameter
Description
Instance Group Name
A unique identifier for the group.
Naming conventions: 2 - 126 characters. Must start with a letter or Chinese character. Supports digits, underscores (_), and hyphens (-).
Database Instance Type
Select PostgreSQL.
Instance Group Type
Select Disaster Recovery.
This mode configures asynchronous, one-way replication from the primary to the secondary node, designed for cross-region failover and recovery drills.
Region of Primary Instance
The region hosting the source instance. This defaults to the current console selection. To switch regions, use the global region selector on the top.
Primary Instance
Select the existing RDS instance to serve as the read/write primary node.
If no primary instance is available, click Create Primary Instance to purchase an RDS for PostgreSQL instance.
Click OK.
The instance group is provisioned and listed in the console. Proceed to add a secondary instance to complete the disaster recovery topology.
From Basic Information page
Go to the RDS Instances page, select a region at the top, and then click the ID of the target RDS for PostgreSQL instance. This instance will be used as the primary instance.
On the Basic Information page, in the Instance Distribution section, click Add next to Disaster Recovery Instance.
The system automatically provisions a GAD group using the current instance as the primary node and directs you to the Add Secondary Instance page.
NoteIf the instance is already configured as the primary node in an active GAD group, the system utilizes the existing group context. No new group is instantiated.
On the Add Secondary Instance page, follow the instructions in Method 1: Create a new instance and add it as a secondary instance.
NoteIf you want to add an existing instance as the secondary instance, close this page and follow the instructions in Method 2: Add an existing instance as a secondary instance.
Delete an instance group
You cannot delete a GAD instance group that still contains a secondary node. Remove the secondary node first to isolate the primary node before deleting the group.
Deleting the logical GAD group and releasing the underlying physical resources are distinct operations with specific dependencies:
Delete instance group: Dissolves the GAD topology and removes the logical grouping. The primary instance remains active, and its data remains intact.
Release primary instance: The primary instance is locked while it's part of a GAD group. You must delete the instance group before you can release or unsubscribe from the primary instance. Once released, the instance follows standard lifecycle policies (e.g., moving to the recycle bin).
If the primary instance is suspended due to overdue payments or subscription expiration, the GAD group is automatically dissolved and the DTS synchronization link is severed. Consequently, the secondary node decouples from the group and promotes itself to a standalone read/write instance.
Go to the Global Active Database page.
Find the instance group to delete and click Delete in the Actions column.
NoteIf the Delete button is grayed out, the instance group still contains a secondary instance. You must remove the secondary instance before you can delete the instance group.
Carefully read the notes in the dialog box that appears. After you confirm the details, click OK to delete the instance group.