Change node configurations for an RDS MySQL Cluster Edition instance-ApsaraDB RDS(RDS)-阿里云帮助中心

RDS MySQL lets you set different specifications for different cluster nodes. You can also adjust the storage class and storage space. This improves the flexibility and cost-effectiveness of the instance.

Prerequisites

The primary RDS MySQL instance must meet the following conditions:

Product series: Cluster Edition
Instance status: Running
The data replication relationship between the primary and secondary nodes of the instance is semi-synchronous or asynchronous.

Limits

Item to change	Change method	Limits
Node specifications	You can change the specifications of a single node or of the entire instance.	Ensure that the specifications of at least one node match the specifications of the primary node. The product type and family of all nodes in the cluster must be the same: Available editions: Yitian Edition or Standard Edition. Family: All nodes must be Dedicated or General-purpose.
Node storage class	Changes can only be made to the entire instance, not to a single node.	Only changes between ESSD PL1, PL2, and PL3 disks are supported.
Node storage space	Changes can only be made to the entire instance, not to a single node.	You can change the storage space for the entire instance in the RDS console or by calling the ModifyDBInstanceSpec API operation.

Note

You can view the node specifications in the topology graph at the bottom of the Basic Information page of the instance.

Impacts

Item to change	Impact
Node specifications	The change takes several minutes and is not affected by the data volume. Changing node specifications causes an instance switchover. Change the specifications during off-peak hours. Make sure your application has an automatic reconnection mechanism. During the instance switchover, most operations related to the database, accounts, and network cannot be performed. For more information, see Impacts of an instance switchover. The details of the instance switchover are as follows: Changing only the secondary node: The secondary node becomes unavailable for a short time. The primary node is not affected. Changing the primary node: A primary/secondary switchover is triggered. The primary node and the secondary node involved in the switchover become unavailable for a short time.
Node storage class	In most cases, an instance switchover is not triggered. If a snapshot task is running on a disk, the disk expansion starts only after the snapshot task is complete.
Node storage space

Note

Changing the configuration does not change the node IDs or endpoints of the instance. You do not need to manually restart the instance after the change is complete.

Billing rules

For information about the billing rules after you change node configurations, see Change configurations.

Procedure

Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.
On the Basic Information page, in the Configuration Information or Instance Topology Management section, click Change Node Specifications.
Set Storage Class, Storage Space, Target Specifications, and Switch Time as needed.
Note
You can only increase the storage space for a node in the RDS console. To decrease the storage space, perform a scale-in by calling the ModifyDBNode API operation.
Read the Terms of Service and click Confirm Order. After you confirm the change information, click Proceed to Pay and complete the payment.
Note
Changing the node configuration takes several minutes. During this process, the instance status is Upgrading/Downgrading. When the process is complete, the instance status changes to Running.

Related operations

You can change the nodes of an RDS MySQL Cluster Edition instance by calling the ModifyDBNode API operation.