You can change the configurations of an instance and its Internet bandwidth after it is created.

Upgrade or downgrade instance configurations

You can only upgrade or downgrade the configurations of vCPU and memory (that is, instance type family) simultaneously by changing the instance type. Depending on the method of billing applied to your instance, you can change an instance type as follows:

Adjust Internet bandwidth

You can adjust the Internet bandwidth of an instance. The methods vary according to your business needs and the billing method of the instance. The following table lists the methods.

Billing method  Supports permanent upgrade? Is it effective immediately?  Available feature  Description
Subscription Yes Yes Upgrade configurations of Subscription instances Only applicable to VPC-Connected ECS instances to which no EIP addresses are attached, or classic network-connected ECS instances. The Internet and intranet IP addresses remain unchanged after you upgrade your configurations.
Subscription Yes Effective from next billing cycle Renew for configuration downgrade Adjust bandwidth in the new billing cycle. When the Internet bandwidth is set to 0 Mbit/s, the Internet IP address of a VPC-Connected instance is released in the new billing cycle, but that of a classic network-connected ECS instance is retained.
Pay-As-You-Go or Subscription Yes Yes Change EIP Internet bandwidth Only applicable to VPC-Connected instances to which EIP addresses are bound. You can adjust the Internet bandwidth on an EIP address at any time.

Assign a public IP address

Assign a public IP address to an ECS instance while creating it. If you skip it, you can even assign after an ECS instance is created. However, the feature is only available for Subscription instances. For more information, see the following table.

Feature Is it effective immediately? Description
Upgrade configurations of Subscription instances Yes Only applicable to VPC-Connected ECS instances to which no EIP addresses are attached, or classic network-connected ECS instances. Set the Internet bandwidth to a non-zero value to assign a public IP address.
Renew for configuration downgrade Effective from next billing cycle