Help Center> Document Database Service> User Guide> Instance Modifications> Changing Replica Set Instance Nodes> Adding Replica Set Instance Nodes
Updated on 2023-03-15 GMT+08:00
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Adding Replica Set Instance Nodes

DDS allows you to scale out a three-node replica set instance to up to five or even seven nodes. All newly added nodes are secondary nodes and support primary/secondary switchovers, improving data reliability.

Precautions

  • To add nodes, instance status must be Available, Deleting backup, or Checking restoration.
  • A DB instance cannot be deleted while nodes are being added.
  • If there are any newly added standby nodes, they will be unable to participate in this switchover. When you add a new standby node, the HA connection address needs to be reconfigured, and the new node is frozen for 12 hours.
  • Nodes cannot be manually deleted.

Pricing Details

  • A pay-per-use instance is still billed on an hourly basis after new nodes are added.
  • If you add nodes to a yearly/monthly instance, you will pay price difference or get a refund.

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and a project.
  3. Click in the upper left corner of the page and choose Databases > Document Database Service.
  4. On the Instances page, click the replica set instance name.
  5. In the Node Information area on the Basic Information page, click Change Secondary Nodes.
  6. Specify Total Nodes and click Next.

    Figure 1 Selecting the number of nodes

    You can add five or seven nodes.

  7. On the displayed page, confirm the node configuration information.

    • For yearly/monthly DB instances
      • If you need to modify your settings, click Previous to go back to the page for you to specify details.
      • If you do not need to modify your settings, click Submit to go to the payment page and complete the payment.
    • For pay-per-use DB instances
      • If you need to modify your settings, click Previous to go back to the page for you to specify details.
      • If you do not need to modify your settings, click Submit to add the nodes.

  8. View the result of adding nodes.

    • When a node is being added, the status of the instance is Adding node. The entire process takes about 15 minutes.
    • In the Node Information area, view the information about the nodes you added.