Performing a Primary/Standby DN Switchover

Scenarios

GaussDB supports primary/standby DN switchover in a shard of an instance when the instance is available. You can promote a standby DN to the primary DN in a shard.

Constraints

• This operation cannot be performed when the node status is abnormal.
• Only one standby node can be specified as the primary node in a shard.
• Single-node instances do not support primary/standby DN switchovers.
• During a primary/standby switchover, the following operations cannot be performed:
  • Rebooting a DB instance
  • Switching AZs
  • Changing vCPUs and memory of an instance
  • Repairing a node
  • Replacing a node
  • Adding nodes
  • Backing up and restoring an instance

Precautions

Services may be interrupted for several seconds or minutes during the switchover. You are advised to perform this operation during off-peak hours.

Procedure

1. Log in to the management console.
2. Click in the upper left corner and select a region and project.

   

3. Click in the upper left corner of the page and choose Databases > GaussDB.
4. Click the target instance name to go to the Basic Information page.
5. In the Node List area, click Switch Primary and Standby DNs.
6. Select an AZ to view the DN shard of the primary DN in the selected AZ. Select the standby DN to be promoted to primary and click OK.
   Figure 1 Switching primary and standby DNs
   
   • If there is no primary DN in the selected AZ, shard information is not displayed.
   • Services may be interrupted for several seconds or minutes during the switchover. You are advised to perform this operation during off-peak hours.
   • Primary/standby switchover can be performed on a maximum of 30 shards at a time.

7. Select the standby DN to be promoted to primary and click OK.