Change configuration-PolarDB(PolarDB)-阿里云帮助中心

When you change a cluster's configuration, the system calculates fees based on the cluster's billing method and the changes made.

Important notes

After you change the configuration—either manually or through auto scaling—you are billed based on the new configuration.

Subscription

Change type	Fee description
Upgrade or add nodes	Payment fee = Total price for the remaining duration of the new configuration (monthly price of the new configuration ÷ 30 ÷ 24 × remaining subscription duration) − total price for the remaining duration of the old configuration (monthly price of the old configuration ÷ 30 ÷ 24 × remaining subscription duration). Example: The new configuration costs CNY 14,400 per month, and the old configuration costs CNY 7,200 per month. The subscription has 50 days remaining. The fee to pay is (14,400 / 30 / 24 × 50 × 24) - (7,200 / 30 / 24 × 50 × 24) = CNY 12,000.
Downgrade or delete nodes	For more information about the fees for downgrading or deleting nodes, see Unsubscription rules.

Pay-as-you-go

Pay-as-you-go clusters are billed hourly. After you change the configuration, they are billed hourly at the new price.

Serverless

You cannot manually change the configurations. The compute nodes of a Serverless cluster are dynamic resources and scale automatically based on system workload.

Note

You can adjust the scaling policy of cluster resources by modifying the Serverless configuration. For more information, see Set Serverless cluster resource scaling policy.

FAQ

Why was my refund for a downgrade less than expected?

Check if either of the following situations occurred before the downgrade:

A discount was applied to the original order: For example, if you purchased the original cluster with a 15% annual discount from the official website, and the original price of the cluster was 1,000 CNY, you actually paid 850 CNY. The refund for the downgrade is calculated based on the actual payment of 850 CNY.
If a voucher was applied to the original order, any refund from a downgrade is calculated based on the actual amount paid. For example, if you paid 500 CNY for the original cluster after using a voucher, the refund is calculated based on this 500 CNY payment.

References

Manual configuration changes
You can manually change the cluster configuration at any time as needed. For more information, see Manually change configurations and Add or remove nodes.
Automatic configuration changes
PolarDB for MySQL provides multiple automatic scaling (elastic scaling) methods. You can configure relevant scaling parameters to enable elastic scaling of cluster specifications. For more information, see automatic scaling (elastic scaling).