Scale a PolarDB for PostgreSQL cluster up or down to match your compute needs—without affecting stored data.
Prerequisites
Before you begin, make sure that:
No specification change task is already in progress on the cluster
Background
PolarDB supports capacity scaling in three dimensions:
Compute scale-up/scale-down: change the node specifications (this topic)
Compute scale-out/scale-in: add or remove read-only nodes. See
Storage scaling: automatically adjusts storage based on data volume, storage type, and billing method. See
Billing
For pricing details, see .
Usage notes
Disconnection during the change
When you change the specifications of a cluster, your applications are temporarily disconnected from the cluster for up to 30 seconds. Schedule the change during off-peak hours and make sure your application reconnects automatically.
Time to complete
The change takes approximately 5 minutes per compute node. For example, a two-node cluster takes about 10 minutes. Actual duration also depends on database load and the number of tables.
Data safety
Data stored in the cluster is not affected.
Centralized cluster (Enterprise Edition or Standard Edition)
You can change the specifications of the entire cluster or an individual node. When changing an individual node, at least one read-only node must retain the same specifications as the primary node.
Distributed cluster
You can only change specifications uniformly across all compute nodes or all data nodes. Changing the specifications of a single compute node, data node, primary node, or read-only node is not supported.
Procedure
Change specifications for a centralized cluster
PolarDB for PostgreSQL centralized clusters are clusters whose Database Edition is Enterprise Edition or Standard Edition.
Log in to the PolarDB console. In the left-side navigation pane, click Clusters. In the upper-left corner, select the region where the cluster resides, then find the cluster.
Go to the Change Configurations page using one of these methods:
In the cluster list, find the cluster and click Change Configurations in the Actions column.
Click the cluster ID, then click Change Configurations in the Database Nodes section.
Select Upgrade or Downgrade, then click OK.
Temporary upgrade is only available for subscription clusters. See .
On the Upgrade/Downgrade page, configure the following parameters.
Parameter Description Specification type The specification type: General Specification or Dedicated Specification Node specification The new node specifications. At least one read-only node must have the same specifications as the primary node. Switching time When the change takes effect. Switch Now applies the change immediately. Switch At schedules the change at a specific time within the next 24 hours; the configuration updates automatically within 30 minutes after the specified time. To view or cancel a scheduled task, see . Complete the payment based on your billing method.
Pay-as-you-go: read and agree to the terms of service, then click Buy Now.
Subscription: read and agree to the terms of service, click Buy Now, then confirm the order and payment method on the Purchase page and click Subscribe.
The new specifications take effect within 10 minutes.
Change specifications for a distributed cluster
Log in to the PolarDB console. In the left-side navigation pane, click Clusters. In the upper-left corner, select the region where the cluster resides, then click the cluster ID to go to the Basic Information page.
In the Configurations section, click Upgrade or Downgrade.
On the Upgrade/Downgrade page, configure the following parameters.
Parameter Description Specification type The specification type: General Specification or Dedicated Specification Node specification The new node specifications. Specifications are applied uniformly to all compute nodes or all data nodes. Changing a single node's specifications is not supported. Switching time When the change takes effect. Switch Now applies the change immediately. Switch At schedules the change at a specific time within the next 24 hours; the configuration updates automatically within 30 minutes after the specified time. To view or cancel a scheduled task, see . Complete the payment based on your billing method.
Pay-as-you-go: read and agree to the terms of service, then click Buy Now.
Subscription: read and agree to the terms of service, click Buy Now, then confirm the order and payment method on the Purchase page and click Subscribe.
The new specifications take effect within 10 minutes.
API reference
| Operation | Description |
|---|---|
| ModifyDBNodeClass | Changes the node specifications of a PolarDB cluster |