Auto Scaling is free of charge. However, you must pay for the resources of other Alibaba Cloud services used in Auto Scaling, such as Elastic Compute Service (ECS), Server Load Balancer (SLB), and ApsaraDB RDS instances.

ECS instances

ECS instances in scaling groups are categorized into the following types:

  • Existing ECS instances that are manually added to a scaling group. The subscription, pay-as-you-go, and preemptible instance billing methods are supported.
  • ECS instances that are automatically created during a scale-out event. Only the pay-as-you-go and preemptible instance billing methods are supported.

The following table describes the ECS instance resources for which you must pay. indicates a billing method that offers discounts to reduce the costs of pay-as-you-go resources. You can purchase pay-as-you-go resources. For more information, see Billing overview.

Resource Description Billing method References
Computing resource (vCPUs and memory) You are charged based on the instance type that you choose. The instance type determines the number of vCPUs and the size of memory that you can use.
  • Subscription
  • Pay-as-you-go
  • Pay-as-you-go and reserved instances
  • Pay-as-you-go and savings plans
  • Preemptible instances
Image The image fees are determined based on the image type and your usage.
  • Subscription
  • Pay-as-you-go
  • Pay-as-you-go and reserved instances
Disk The disk fees are determined based on the disk capacity and duration of use.
  • Subscription
  • Pay-as-you-go
  • Pay-as-you-go and storage capacity units (SCUs)
  • Pay-as-you-go and savings plans
Snapshot The snapshot fees are determined based on the snapshot size and storage duration.
  • Pay-as-you-go
  • Pay-as-you-go and SCUs
Public bandwidth If you use a public IP address to access the Internet, you are charged only for the outbound public bandwidth.
  • Pay-by-bandwidth
  • Pay-by-traffic
  • Pay-by-bandwidth and savings plans
  • Pay-by-traffic and data transfer plans

The following table describes the billing methods of ECS instances in different states. For more information, see No Fees for Stopped Instances (VPC-Connected).

Billing method of ECS instances ECS instance state Billing of additional ECS resources
Subscription Running You are charged for the additional ECS resources such as images, disks, public bandwidth, and snapshots based on their individual billing methods.
Stopped You are charged for the additional ECS resources such as images, disks, public bandwidth, and snapshots based on their individual billing methods.
Pay-as-you-go (including preemptible instances) Running You are charged for the additional ECS resources such as images, disks, public bandwidth, and snapshots based on their individual billing methods.
Stopped
  • If the No Fees for Stopped Instances (VPC-Connected) feature is disabled, you are charged for the additional ECS resources such as images, disks, public bandwidth, and snapshots based on their individual billing methods.
  • The following section describes the status of the additional ECS resources if the No Fees for Stopped Instances (VPC-Connected) feature is enabled:
    • Image: Images are retained. The billing for paid images continues.
    • Disk: Disks are retained, and the billing continues.
    • Public bandwidth:
      • If ECS instances are assigned public IP addresses, the IP addresses are released and you are no longer charged for the public bandwidth.
      • If ECS instances are associated with elastic IP addresses (EIPs), the EIPs remain unchanged. You are charged for the EIPs until the ECS instances are stopped.
      Note After ECS instances are stopped, the private IP addresses of the instances remain unchanged.
    • Snapshot: Snapshots are retained, and the billing continues.

Other Alibaba Cloud services

Auto Scaling does not create resources listed in the following table. Auto Scaling must associate scaling groups with these resources during the usage. You must create and pay for these resources in advance by using the consoles of other Alibaba Cloud services or by calling API operations of other Alibaba Cloud services.

Service Description References
Server Load Balancer (SLB) If you want to associate a scaling group with SLB instances, you must create and pay for the SLB instances in advance. Pay-as-you-go
RDS If you want to associate a scaling group with RDS instances, you must create and pay for the RDS instances in advance. Pricing, billable items, and billing methods