A global database network (GDN) links PolarDB for PostgreSQL clusters across regions, enabling cross-region disaster recovery and active geo-redundancy. This topic covers how to create and delete a GDN.
Prerequisites
Before you begin, ensure that:
The cluster you want to use as the primary cluster runs PostgreSQL 14, Enterprise Edition, with High-availability Mode set to Single zone (hot standby storage cluster disabled)
For secondary clusters in regions outside the Chinese mainland: you have signed the Cross-Border Data Transfer Compliance Agreement
Limitations
Cluster topology
| Primary cluster | Secondary cluster | |
|---|---|---|
| Count | 1 | Up to 4 |
| Database engine version | PostgreSQL 14 | PostgreSQL 14 (must match primary) |
| Node specifications | — | Must be ≥ primary cluster specs |
| GDN membership | Can belong to only one GDN | Can belong to only one GDN |
Supported regions
GDN is available in more than 10 regions worldwide.
| Primary cluster region | Supported secondary cluster regions |
|---|---|
| Any region in the Chinese mainland | Same region as primary, or any other region in the Chinese mainland. For other region combinations, submit a ticket.submit a ticket |
| Any region outside the Chinese mainland | China (Hong Kong), Japan (Tokyo), South Korea (Seoul), Singapore, Malaysia (Kuala Lumpur), Indonesia (Jakarta), Philippines (Manila), Thailand (Bangkok), Germany (Frankfurt), US (Silicon Valley), US (Virginia), UK (London) |
For secondary clusters in regions outside the Chinese mainland, sign the Cross-Border Data Transfer Compliance Agreement before creating the secondary cluster.Cross-Border Data Transfer Compliance Agreement
Unsupported features
Clusters in a GDN do not support:
Database and table restoration
Billing
Cross-region data transfer within a GDN is free. You pay only for the PolarDB clusters themselves.
Create a GDN
Before starting, decide which existing cluster to use as the primary cluster and note its region.
Log on to the PolarDB console. In the left navigation pane, click Global Database Network (GDN).
On the Global Database Network (GDN) page, click Create Global Database Network.
In the Create Global Database Network (GDN) dialog box, configure the following parameters.
Parameter Description Compatibility Select PostgreSQL. Version Fixed to Single-active Version. Name Enter a descriptive name for the GDN. The name does not need to be unique. Primary Region Select the region where the primary cluster is located. Primary Cluster Select the cluster to use as the primary cluster. Global Domain Name Not currently supported. Keep this disabled. Click OK.
The GDN appears on the Global Database Network (GDN) page. To extend it across regions, to the GDN.
Delete a GDN
To protect business-critical data, GDN deletion is a two-phase process: remove all secondary clusters first, then delete the GDN.
You can delete a GDN only if it contains only the primary cluster.
A deleted GDN cannot be recovered.
After deletion, applications connected to the GDN lose database access. Update the connection strings in your applications immediately.
Log on to the PolarDB console. In the left navigation pane, click Global Database Network (GDN).
On the Global Database Network (GDN) page, find the target GDN and click Delete in the Actions column.
If Delete is grayed out, the GDN still has secondary clusters. Remove all secondary clusters first, then retry.
In the dialog box, review the warnings and click OK to confirm deletion.
What's next
Global Database Network (GDN) — GDN architecture and use cases
Add and manage a secondary cluster — Add secondary clusters and switch the primary cluster
Connect to a global database network — Connect to a GDN
API reference
| API | Description |
|---|---|
| CreateGlobalDatabaseNetwork | Creates a global database network. |
| DeleteGlobalDatabaseNetwork | Deletes a global database network. |
| DescribeGlobalDatabaseNetwork | Queries the information of a specific global database network. |
| DescribeGlobalDatabaseNetworks | Queries the information of all global database networks. |
| ModifyGlobalDatabaseNetwork | Modifies the information of a global database network. |
FAQ
How many GDNs can I create?
There is no limit on the number of GDNs per Alibaba Cloud account.
Can I change the primary cluster after creating a GDN?
Yes. Switch the primary cluster from the GDN management page in the console.