This topic describes how to add nodes to or delete nodes from an ApsaraDB RDS for PostgreSQL cluster (RDS Cluster Edition).
Prerequisites
Before you begin, make sure that:
-
An RDS cluster (RDS Cluster Edition) is created
-
The cluster is in the Running state
How it works
An RDS cluster consists of one primary node and one or more secondary nodes.
| Constraint | Detail |
|---|---|
| Maximum cluster size | One primary node and up to eight secondary nodes (nine nodes total) |
| Minimum cluster size | One primary node and one secondary node |
| Load balancing | After adding a node, assign a weight to control how much traffic it receives |
| Adding a node | Read and write traffic to other nodes is not affected |
| Deleting a node | The cluster's data and connections to other nodes are not affected. Connections to the deleted node are briefly interrupted during removal. |
To minimize connection interruptions when deleting a node, specify a weight for the node so that the system stops forwarding requests to it before you delete it. You do not need to modify your application configuration.
Billing
Adding or deleting nodes changes your instance specifications, which affects billing. For details, see Change instance specifications.
Add a node
-
Go to the Instances page. In the top navigation bar, select the region where the instance resides. Find the instance and click its ID.
-
On the Basic Information page, scroll to the Instance Topology Management section and click Add or Delete Node.
-
In the dialog box, select Add Node and click Next step.
-
In the Nodes section, click
or Add Node. Specify a zone and vSwitch for the new node.To cancel adding a node, click
to the left of the node. -
Read and select Terms of Service, then click Pay Now.
Delete a node
Deleting a node removes it from the cluster. The cluster's data and connections to other nodes are not affected. Only connections to the deleted node are briefly interrupted during removal.
-
Go to the Instances page. In the top navigation bar, select the region where the instance resides. Find the instance and click its ID.
-
On the Basic Information page, scroll to the Instance Topology Management section and click Add or Delete Node.
-
In the dialog box, select Delete Node and click Next step.
-
Click
to the left of the node you want to delete.To cancel the deletion, click Restore to the left of that node.
-
Read and select Terms of Service, then click Pay Now.
API operations
| Operation | Description |
|---|---|
| CreateDBNodes | Adds nodes to an RDS cluster |
| DeleteDBNodes | Deletes nodes from an RDS cluster |