PolarDB:Enable the GDN service

Create a Global Database Network

1. Log on to the PolarDB-X console. In the upper-left corner of the page, select the region where the target instance is located.

2. On the Instances page, click the PolarDB-X 2.0 tab. Find the target instance and click the instance ID.

3. On the Basic Information page, click Create GDN.

   

5. In the dialog box, configure the following parameters.

   • Name: Enter a descriptive name for the GDN. The name is used for identification and does not need to be unique.

   • Region: Select the region where the primary instance is located.

     Note

     You must first decide which instance will be the primary instance before you select its region.

   • Primary Instance: Select an existing instance to use as the primary instance for the GDN.

   • GDN Mode: Select a GDN mode.

     • Active-passive mode: Read requests are sent to the local instance, and write requests are sent to the primary instance.

     • Multi-active mode: Supports bidirectional data writes between the primary and secondary instances. This helps you build a geo-redundant database service to improve business continuity and the access experience.

   • Synchronize DDL: Select whether to synchronize DDL statements among GDN instances.

   • DML Replication Policy: Select a DML replication policy.

   • Conflict Policy: Select a data conflict resolution policy.

     Note

     This parameter is available only when you select Multi-active mode.

6. After you complete the configuration, click OK.

Manage the Global Database Network

Log on to the PolarDB-X console. In the navigation pane on the left, click GDN to go to the GDN list page. On this page, you can manage your GDN.

Add a read-only instance

1. Log on to the PolarDB-X console. In the navigation pane on the left, click GDN to go to the GDN list page.

2. Find the target GDN and click its GDN ID.

3. On the GDN details page, click Add Secondary Instance to the right of Primary Instance.

4. In the Add Secondary Instance dialog box, Select Secondary Instance Purchase Method: Subscription or Pay-as-you-go.

   

   Note

   • You cannot add an existing instance as a secondary instance. You must purchase a new instance in the Add Secondary Instance dialog box.

   • Subscription is a prepayment method that is suitable for long-term use and is more cost-effective than pay-as-you-go.

   • Pay-as-you-go is a post-payment method where you are billed hourly. This method is suitable for short-term needs. You can release the cluster at any time to save costs.

   • A secondary instance is created by restoring data from an existing backup. This process uses an independent data restoration channel instead of pulling full data from the primary instance and does not affect the performance of the primary instance.

5. On the instance purchase page, configure the following parameters. For more information about the other parameters, see Parameters for creating an instance.

   Parameter	Description
   Region of Backup Set	The region where the backup set of the secondary instance is located.
   Global Database Network	Pin the Replica Instance.
   Region	The region where the secondary instance is located. You cannot change the region after purchase. Note You can only select a region that corresponds to the region of the primary instance. For more information, see the mapping table for primary and secondary instance regions.
   Database Engine	This must be the same as the database engine of the primary instance.

6. Click Buy Now to complete the purchase.

7. Return to the GDN details page. Click The instance is added. Refresh the page. or refresh the page to view the new secondary instance.