CreateScalingGroup

Updated at:

Creates a scaling group to automatically adjust your compute capacity (the number of instances) based on business changes and policies.

Operation description

A scaling group is a collection of ECS instances that are used in the same common scenarios.

The number of scaling groups that can be created in a region depends on your Auto Scaling usage. Go to Quota Center to view the quota for the total number of scaling groups.

A scaling group does not take effect immediately after it is created. You must invoke the EnableScalingGroup operation to enable the scaling group before it can trigger scaling activities and execute scaling rules.

The scaling group, the associated Classic Load Balancer (CLB, formerly SLB) instances, and the associated ApsaraDB RDS instances must be in the same region. For more information, see Regions and active zones.

If you associate a CLB instance with the scaling group, the scaling group automatically adds ECS instances that are added to the scaling group to the backend server group of the CLB instance. You can specify the server groups to which ECS instances are added. The following two types of server groups are supported:

  • Default server group: used to accept frontend requests. If no virtual server group or primary/secondary server group is configured for a listener, requests are forwarded to the ECS instances in the default server group by default.

  • Virtual service group: when you need to forward different requests to different backend servers, or forward requests based on domain names or URLs, you can use virtual service groups.

Note

If you specify both the default server group and multiple virtual service groups, ECS instances are added to all of these server groups.

After an instance is added to the backend server group of a CLB instance, the default weight of the instance is 50. The CLB instance must meet the following requirements:

  • The CLB instance must be in the active state. You can call the DescribeLoadBalancers operation to query the status of the specified CLB instance.

  • Health checks must be enabled for all listener ports configured on the CLB instance. Otherwise, the scaling group fails to be created.

If you associate an Application Load Balancer (ALB) server group, a Network Load Balancer (NLB) server group, or a Gateway Load Balancer (GWLB) server group with the scaling group, the scaling group automatically adds ECS instances that are added to the scaling group as backend servers of the ALB, NLB, or GWLB server group to process access requests distributed by the ALB, NLB, or GWLB instance. You can specify multiple ALB, NLB, or GWLB server groups, but the server groups must belong to the same VPC as the scaling group. For more information, see AttachAlbServerGroups or AttachServerGroups.

If you associate an ApsaraDB RDS instance with the scaling group, the scaling group automatically adds the internal IP addresses of ECS instances that are added to the scaling group to the whitelist of the ApsaraDB RDS instance. The ApsaraDB RDS instance must meet the following requirements:

  • The ApsaraDB RDS instance must be in the Running state. You can call the DescribeDBInstances operation to query the status of the specified ApsaraDB RDS instance.

  • The number of IP addresses in the whitelist of the ApsaraDB RDS instance must not exceed the upper limit. For more information, see Configure a whitelist in the ApsaraDB RDS documentation.

If MultiAZPolicy of the scaling group is set to COST_OPTIMIZED:

  • When you specify the OnDemandBaseCapacity, OnDemandPercentageAboveBaseCapacity, and SpotInstancePools parameters, the instance allocation method under the cost optimization strategy is specified and takes priority during scale-out and scale-in events.

  • When you do not specify the OnDemandBaseCapacity, OnDemandPercentageAboveBaseCapacity, or SpotInstancePools parameters, the cost optimization policy creates instances only in the most cost-effective manner. (In this pattern, instances cannot be created through Elasticity Assurance or Capacity Reservation. The vSwitch parameter for secondary elastic network interface controllers (NICs) is not supported.)

If you set propagatable tags for the scaling group, that is, Tags.Propagate is set to true:

  • Tags on the scaling group are propagated only to newly created instances, not to instances that are already running in the scaling group.

  • If you specify instance tags in the scaling configuration and choose to propagate the scaling group tags to the instance, all tags coexist.

  • If a propagatable tag on the scaling group and a tag in the scaling configuration have the same tag key, the tag value in the scaling configuration takes precedence.

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Test

RAM authorization

The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

  • Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.

  • API: The API that you can call to perform the action.

  • Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.

  • Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.

    • For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.

    • For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.

  • Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.

  • Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

Action

Access level

Resource type

Condition key

Dependent action

ess:CreateScalingGroup

create

*ScalingGroup

acs:ess:{#regionId}:{#accountId}:scalinggroup/*

None None

Request parameters

Parameter

Type

Required

Description

Example

ScalingGroupName

string

No

The name of the scaling group. The name must be unique within a region.

The name must be 2 to 64 characters in length and can contain letters, digits, underscores (_), hyphens (-), and periods (.). It must start with a digit, letter, or Chinese character.

Default value: the value of ScalingGroupId.

scalinggroup****

LaunchTemplateId

string

No

The ID of the launch template from which the scaling group obtains launch configuration information.

lt-m5e3ofjr1zn1aw7****

LaunchTemplateVersion

string

No

The version of the launch template. Valid values:

  • A fixed template version number.

  • Default: always uses the default version of the template.

  • Latest: always uses the latest version of the template.

Default

InstanceId

string

No

The ID of the instance. When you create a scaling group, the required configuration information is obtained from the specified instance, and a scaling configuration is created through automatic creation.

i-28wt4****

RegionId

string

Yes

The region ID of the scaling group. For more information, see Regions and zones.

cn-qingdao

MinSize

integer

Yes

The minimum number of instances in the scaling group. When the number of instances in the scaling group is less than the value of MinSize, Auto Scaling uses automatic creation to create instances.

Note

The value of MinSize must be less than or equal to the value of MaxSize.

2

MaxSize

integer

Yes

The maximum number of instances in the scaling group. When the number of instances in the scaling group is greater than the value of MaxSize, Auto Scaling automatically removes instances.

The value range of MaxSize depends on your Auto Scaling usage. Go to Quota Center to view the quota for Maximum Number of Instances in a Scaling Group.

If the quota for Maximum Number of Instances in a Scaling Group is 2000, the value range of MaxSize is 0 to 2000.

20

DefaultCooldown

integer

No

The cooldown time after a scaling activity (adding or removing instances) is complete. Valid values: 0 to 86400. Unit: seconds.

During the cooldown time, the scaling group does not execute other scaling activities. This applies only to scaling activities triggered by CloudMonitor event-triggered tasks.

Default value: 300.

300

LoadBalancerIds

string

No

The IDs of CLB (formerly SLB) instances. The value is a JSON array that consists of CLB instance IDs separated by commas (,).

The total number of CLB instances that can be associated with a single scaling group depends on your Auto Scaling usage. Go to Quota Center to view the quota for Total Number of Load Balancing Instances That Can Be Associated with a Scaling Group.

["lb-bp1u7etiogg38yvwz****", "lb-bp168cqrux9ai9l7f****", "lb-bp1jv3m9zvj22ufxp****"]

DBInstanceIds

string

No

The IDs of ApsaraDB RDS instances. The value is a JSON array that consists of ApsaraDB RDS instance IDs separated by commas (,).

The total number of ApsaraDB RDS instances that can be associated with a single scaling group depends on your Auto Scaling usage. Go to Quota Center to view the quota for Total Number of RDS Instances That Can Be Associated with a Scaling Group.

["rm-bp142f86de0t7****", "rm-bp18l1z42ar4o****", "rm-bp1lqr97h4aqk****"]

RemovalPolicy.1

string

No

The first-round filter strategy for the scale-in policy. The value must be different from the values of RemovalPolicy.2 and RemovalPolicy.3. Valid values:

  • OldestInstance: removes the ECS instance that was earliest added to the scaling group.

  • NewestInstance: removes the ECS instance that was most recently added to the scaling group.

  • OldestScalingConfiguration: removes the ECS instance that was created based on the earliest scaling configuration.

  • CustomPolicy: removes ECS instances based on a custom scale-in policy (Function).

The scaling configuration mentioned in OldestScalingConfiguration refers to the instance configuration source in the scaling group, including scaling configurations and launch templates. CustomPolicy can only be set as the first-round scale-in policy. When you specify CustomPolicy, you must also specify the CustomPolicyARN parameter.

Note

The removal of ECS instances from a scaling group is also affected by the scaling policy (MultiAZPolicy) of the scaling group. For more information, see Configure a combination policy for removing instances.

OldestScalingConfiguration

RemovalPolicy.2

string

No

The second-round filter strategy for the scale-in policy. The value must be different from the values of RemovalPolicy.1 and RemovalPolicy.3. Valid values:

  • OldestInstance: removes the ECS instance that was earliest added to the scaling group.

  • NewestInstance: removes the ECS instance that was most recently added to the scaling group.

  • OldestScalingConfiguration: removes the ECS instance that was created based on the earliest scaling configuration.

Note

The removal of ECS instances from a scaling group is also affected by the scaling policy (MultiAZPolicy) of the scaling group. For more information, see Configure a combination policy for removing instances.

OldestInstance

RemovalPolicy.3

string

No

The third-round filter strategy for the scale-in policy. The value must be different from the values of RemovalPolicy.1 and RemovalPolicy.2. Valid values:

  • OldestInstance: removes the ECS instance that was earliest added to the scaling group.

  • NewestInstance: removes the ECS instance that was most recently added to the scaling group.

  • OldestScalingConfiguration: removes the ECS instance that was created based on the earliest scaling configuration.

Note

The removal of ECS instances from a scaling group is also affected by the scaling policy (MultiAZPolicy) of the scaling group. For more information, see Configure a combination policy for removing instances.

NewestInstance

VSwitchId

string

No

The ID of the vSwitch. If you specify this parameter, the network type of the scaling group is VPC.

Note

If neither VSwitchId nor VSwitchIds.N is specified for the scaling group, the network type of the scaling group defaults to classic network.

vsw-bp14zolna43z266bq****

MultiAZPolicy

string

No

The scaling policy for ECS instances in a multi-zone scaling group. Valid values:

  • PRIORITY: the vSwitch specified first (VSwitchIds.N) has the highest priority. Auto Scaling preferentially attempts to scale instances in the zone where the highest-priority vSwitch resides. If the scaling cannot be completed, Auto Scaling automatically attempts to scale instances in the zone where the next-priority vSwitch resides.

  • COST_OPTIMIZED: during scale-out events, Auto Scaling attempts to create ECS instances in ascending order of vCPU unit price. During scale-in events, Auto Scaling attempts to remove ECS instances in descending order of vCPU unit price. If the scaling configuration specifies multiple instance types with preemptible billing methods, spot instances are preferentially created. You can use the CompensateWithOnDemand parameter to specify whether to automatically create pay-as-you-go instances when spot instances cannot be created due to insufficient inventory.

    Note

    COST_OPTIMIZED takes effect only when the scaling configuration specifies multiple instance types or uses spot instances.

  • BALANCE: ECS instances are evenly allocated across the multiple active zones specified for the scaling group. If instances become unevenly distributed across zones due to insufficient inventory, you can call the RebalanceInstance operation to rebalance resources.

  • COMPOSABLE: a composable strategy that allows you to combine the preceding multi-zone scaling policies as needed, or further specify parameters for more fine-grained control over the capacity of the scaling group.

Default value: PRIORITY.

PRIORITY

HealthCheckType

string

No

The health check mode of the scaling group. Valid values:

  • NONE: no health check is performed.

  • ECS: health checks are performed on instances in the scaling group (this value is used to enable instance health checks for both ECS-type and ECI-type scaling groups).

  • LOAD_BALANCER: the instance health status is determined based on load balancing health check results (CLB-type load balancing is not supported).

Default value: ECS.

Note

To enable both instance health checks and load balancing health checks, use the HealthCheckTypes parameter.

ECS

ScalingPolicy

string

No

Specifies the reclaim pattern of the scaling group. Valid values:

  • recycle: the scaling group uses the shutdown and reclaim pattern.

  • release: the scaling group uses the release pattern.

  • forcerelease: the scaling group uses the forced release pattern.

    Note

    If you select forcerelease, running instances are forcefully released during scale-down activities. A forced release is equivalent to a power-off operation, which erases temporary data in the memory and storage of the instance. The data cannot be recovered. Proceed with caution.

  • forcerecycle: the scaling group uses the forced shutdown and reclaim pattern.

    Note

    If you select forcerecycle, running instances are forcefully shut down during scale-down activities. A forced shutdown is equivalent to a power-off operation, which erases temporary data in the memory and storage of the instance. The data cannot be recovered. Proceed with caution.

ScalingPolicy specifies the revoke pattern of the scaling group. The specific action taken when an instance is removed from the scaling group is determined by the RemovePolicy parameter of RemoveInstances. For more information, see RemoveInstances.

recycle

ClientToken

string

No

The client token that is used to ensure the idempotence of the request.

Generate a value from your client that is unique among different requests. The value can contain only ASCII characters and cannot exceed 64 characters in length. For more information, see How to ensure idempotence.

123e4567-e89b-12d3-a456-42665544****

OnDemandBaseCapacity

integer

No

The minimum number of pay-as-you-go instances required in the scaling group. Valid values: 0 to 1000. When the number of pay-as-you-go instances is less than this value, pay-as-you-go instances are preferentially created.

When MultiAZPolicy is set to COMPOSABLE, the default value is 0.

30

OnDemandPercentageAboveBaseCapacity

integer

No

The percentage of pay-as-you-go instances among the excess instances after the minimum number of pay-as-you-go instances (OnDemandBaseCapacity) is met. Valid values: 0 to 100.

When MultiAZPolicy is set to COMPOSABLE, the default value is 100.

20

SpotInstanceRemedy

boolean

No

Specifies whether to supplement spot instances. When enabled, the scaling group attempts to create new instances to replace spot instances that are about to be reclaimed after a reclamation notification is received.

true

CompensateWithOnDemand

boolean

No

Specifies whether to automatically create pay-as-you-go instances to meet the required number of ECS instances when spot instances cannot be created due to price or inventory reasons. This parameter takes effect only when MultiAZPolicy is set to COST_OPTIMIZED. Valid values:

  • true: allowed.

  • false: not allowed.

Default value: true.

true

SpotInstancePools

integer

No

The number of available instance types. The scaling group creates spot instances across multiple types at the lowest cost. Valid values: 1 to 10.

When MultiAZPolicy is set to COMPOSABLE, the default value is 2.

5

DesiredCapacity

integer

No

The expected number of instances in the scaling group. The scaling group automatically maintains the number of ECS instances at the expected number of instances. The value must not be greater than MaxSize or less than MinSize.

5

GroupDeletionProtection

boolean

No

Specifies whether to enable deletion protection for the scaling group. Valid values:

  • true: enables deletion protection. The scaling group cannot be deleted.

  • false: disables deletion protection.

Default value: false.

true

GroupType

string

No

The type of instances managed by the scaling group. Valid values:

  • ECS: the scaling group manages ECS instances.

  • ECI: the scaling group manages Elastic Container Instance (ECI) instances.

Default value: ECS.

ECS

ContainerGroupId

string

No

The instance ID of the ECI instance, which is the container group ID.

eci-uf6fonnghi50u374****

VSwitchIds

array

No

The IDs of one or more vSwitches. If you specify the VSwitchIds parameter, the VSwitchId parameter is ignored. If you specify this parameter, the network type of the scaling group is VPC.

When you specify multiple vSwitches:

  • The vSwitches must belong to the same VPC.

  • The vSwitches can belong to different zones.

  • The priority of vSwitches is determined in ascending numerical order, with 1 indicating the highest priority. When an ECS instance cannot be created in the zone where a higher-priority vSwitch resides, the system automatically selects the next-priority vSwitch to create the ECS instance.

Note

If neither VSwitchId nor VSwitchIds is specified for the scaling group, the network type of the scaling group defaults to classic network.

vsw-bp14zolna43z266bq****

string

No

The IDs of one or more vSwitches. If you specify the VSwitchIds.N parameter, the VSwitchId parameter is ignored. If you specify this parameter, the network type of the scaling group is VPC.

When you specify multiple vSwitches:

  • The vSwitches must belong to the same VPC.

  • The vSwitches can belong to different zones.

  • The priority of vSwitches is determined in ascending numerical order, with 1 indicating the highest priority. When an ECS instance cannot be created in the zone where a higher-priority vSwitch resides, the system automatically selects the next-priority vSwitch to create the ECS instance.

Note

If neither VSwitchId nor VSwitchIds.N is specified for the scaling group, the network type of the scaling group defaults to classic network.

vsw-bp14zolna43z266bq****

LifecycleHook

array<object>

No

The lifecycle hook information.

object

No

The lifecycle hook information.

DefaultResult

string

No

The action to take after the wait state ends. Valid values:

  • CONTINUE: continues to respond to the scale-out activity or continues to respond to the scale-in activity.

  • ABANDON: releases ECS instances created during scale-out events or removes ECS instances from the scaling group during scale-in events.

When a scale-in event (SCALE_IN) occurs in the scaling group and triggers multiple lifecycle hooks, if the wait state of a lifecycle hook with DefaultResult set to ABANDON ends, the wait states of other corresponding lifecycle hooks end early. In other cases, the next action is determined by the last lifecycle hook whose wait state ends.

Default value: CONTINUE.

CONTINUE

LifecycleHookName

string

No

The name of the lifecycle hook. The name cannot be modified after it is specified. If not specified, the default value is the lifecycle hook ID.

lifecyclehook****

LifecycleTransition

string

No

The type of scaling activity to which the lifecycle hook applies. Valid values:

  • SCALE_OUT: scale-out events of the scaling group.

  • SCALE_IN: scale-in events of the scaling group.

Note

If a lifecycle hook is specified for the scaling group, this parameter is required. Other related parameters are optional.

SCALE_OUT

NotificationMetadata

string

No

The fixed string information for the wait state of a scaling activity. The value cannot exceed 128 characters in length. Each time Auto Scaling pushes a notification to the Notification Recipient, it also sends the predefined NotificationMetadata parameter value, which helps you manage and mark notification information of different categories. This parameter takes effect only when the NotificationArn parameter is also specified.

Test

NotificationArn

string

No

The identifier of the notification object for the lifecycle hook. The following types of notification objects are supported: Simple Message Queue (formerly MNS) queues and topics. The parameter value is in the format of acs:ess:{region}:{account-id}:{resource-relative-id}.

  • region: the region where the scaling group resides.

  • account-id: the Alibaba Cloud account ID.

Examples:

  • MNS queue: acs:ess:{region}:{account-id}:queue/{queuename}.

  • MNS topic: acs:ess:{region}:{account-id}:topic/{topicname}.

acs:ess:cn-hangzhou:1111111111:queue/queue2

HeartbeatTimeout

integer

No

The wait time set by the lifecycle hook for the scaling activity. After the wait state times out, the next action is taken. Valid values: 30 to 21600. Unit: seconds.

After a lifecycle hook is created, you can call the RecordLifecycleActionHeartbeat operation to extend the wait time of an ECS instance, or call the CompleteLifecycleAction operation to end the wait state of a scaling activity early.

Default value: 600.

600

VServerGroup

array<object>

No

The information about the virtual service groups associated with the scaling group.

array<object>

No

The information about the virtual service groups associated with the scaling group.

VServerGroupAttribute

array<object>

No

The attributes of the backend server group.

object

No

The attributes of the backend server group.

VServerGroupId

string

No

The ID of the virtual service group.

For more information, see AttachVServerGroups.

rsp-bp1443g77****

Weight

integer

No

The weight allocated to an ECS instance as a backend server after Auto Scaling adds the instance to the virtual service group. A higher weight indicates that the instance receives more access requests. If the weight is 0, the instance does not receive access requests. Valid values: 0 to 100. Default value: 50.

For more information, see AttachVServerGroups.

100

Port

integer

No

The port number used by the ECS instance after Auto Scaling adds the instance to the virtual service group. Valid values: 1 to 65535.

For more information, see AttachVServerGroups.

22

LoadBalancerId

string

No

The ID of the CLB (formerly SLB) instance to which the virtual service group belongs.

For more information, see AttachVServerGroups.

lb-bp1u7etiogg38yvwz****

Tag

array<object>

No

The tags of the scaling group.

object

No

The tags of the scaling group.

Key

string

No

The tag key of the scaling group.

Department

Value

string

No

The tag value of the scaling group.

Finance

Propagate

boolean

No

Specifies whether the tag is a propagatable tag. Valid values:

  • true: tags on the scaling group are propagated only to newly created instances, not to instances that are already running in the scaling group.

  • false: tags on the scaling group are not propagated to instances.

Default value: false.

false

LaunchTemplateOverride

array<object>

No

The launch template override information.

object

No

The launch template override information.

InstanceType

string

No

When you want the scaling group to scale based on the capacity of instance types, specify both this parameter and LaunchTemplateOverride.N.WeightedCapacity.

This parameter specifies the instance type and overrides the instance type in the launch template. You can specify N values for this parameter to extend the launch template to support N instance types. Valid values of N: 1 to 20.

Note

This parameter takes effect only when the LaunchTemplateId parameter specifies a launch template.

Valid values of InstanceType: ECS instance types that are available for purchase. For more information, see Instance families.

ecs.c5.xlarge

WeightedCapacity

integer

No

When you want the scaling group to scale based on the capacity of instance types, specify this parameter after you specify LaunchTemplateOverride.N.InstanceType. The two parameters correspond to each other, and N must be consistent.

This parameter specifies the weight of the instance type, which represents the capacity of a single instance of this type in the scaling group. A higher weight means fewer instances of this type are needed to meet the expected capacity.

Because instance types differ in the number of vCPUs, memory size, and other performance metrics, you can assign different weights to different instance types based on your requirements.

Example:

  • Current capacity: 0.

  • Expected capacity: 6.

  • Capacity of ecs.c5.xlarge: 4.

To meet the expected capacity, the scaling group scales out 2 ecs.c5.xlarge instances.

Note

During scale-out events, the capacity of the scaling group must not exceed the sum of the maximum capacity (MaxSize) and the maximum weight of the instance types.

Valid values of WeightedCapacity: 1 to 500.

4

SpotPriceLimit

number

No

The maximum bid price for the instance type specified by LaunchTemplateOverride.N.InstanceType. You can specify N values for this parameter to extend the launch template to support N instance types. Valid values of N: 1 to 20.

Note

This parameter takes effect only when the LaunchTemplateId parameter specifies a launch template.

0.025

AlbServerGroup

array<object>

No

The information about ALB server groups.

object

No

The information about ALB server groups.

AlbServerGroupId

string

No

The ID of the ALB server group.

N is the serial number of the ALB server group. The number of ALB server groups that can be associated with a scaling group is limited. To view or request a quota increase, go to Quota Center.

sgp-ddwb0y0g6y9bjm****

Weight

integer

No

The weight of an ECS instance as a backend server after Auto Scaling adds the instance to the ALB server group. A higher weight indicates that the instance receives more access requests. If the weight is 0, the instance does not receive access requests. Valid values: 0 to 100.

N is the serial number of the ALB server group.

100

Port

integer

No

The port number used by the ECS instance after Auto Scaling adds the instance to the ALB server group. Valid values: 1 to 65535.

N is the serial number of the ALB server group.

Note

If N is the same but Port is different, the system associates multiple ALB server groups with different ports to the scaling group.

22

ServerGroup

array<object>

No

The information about load balancing server groups.

Note

You cannot specify the same server group information in both AlbServerGroups and ServerGroups.

object

No

The information about load balancing server groups.

ServerGroupId

string

No

The ID of the server group.

sgp-5yc3bd9lfyh*****

Type

string

No

The type of the server group. Valid values:

  • ALB: Application Load Balancer (ALB).

  • NLB: Network Load Balancer (NLB).

  • GWLB: Gateway Load Balancer (GWLB).

ALB

Weight

integer

No

The weight allocated to an ECS instance as a backend server after Auto Scaling adds the instance to the server group. Valid values: 0 to 100.

A higher weight indicates that the instance receives more access requests. If the weight is 0, the instance does not receive access requests.

Note

This parameter is required for ALB and NLB load balancing server groups. This parameter cannot be set for GWLB load balancing server groups.

100

Port

integer

No

The port number used by the ECS instance after Auto Scaling adds the instance to the server group. Valid values: 1 to 65535.

Note

This parameter is required for ALB and NLB load balancing server groups. This parameter cannot be set for GWLB load balancing server groups, and the default value is 6081.

22

AzBalance

boolean

No

Specifies whether to evenly distribute the capacity of the scaling group across multiple zones. This parameter takes effect only when MultiAZPolicy is set to COMPOSABLE. Valid values:

  • true: the capacity of the scaling group is evenly distributed across multiple zones.

  • false: the capacity of the scaling group is not evenly distributed across multiple zones.

Default value: false.

false

AllocationStrategy

string

No

The capacity allocation strategy that determines how the scaling group selects available instance types to meet capacity requirements. The capacity allocation strategy applies to both pay-as-you-go and spot capacity. This parameter takes effect only when MultiAZPolicy is set to COMPOSABLE. Valid values:

  • priority: instances are created in the order of the configured instance types.

  • lowestPrice: instances are created in ascending order of vCPU unit price.

Default value: priority.

priority

SpotAllocationStrategy

string

No

The spot capacity allocation strategy. You can use this parameter to specify the allocation strategy for spot capacity separately. This parameter takes effect only when MultiAZPolicy is set to COMPOSABLE. Valid values:

  • priority: instances are created in the order of the configured instance types.

  • lowestPrice: instances are created in ascending order of vCPU unit price.

Default value: priority.

lowestPrice

MaxInstanceLifetime

integer

No

The maximum amount of time that an instance can exist in the scaling group. Unit: seconds.

Valid values: [86400, Integer.maxValue].

Default value: null.

Note

This parameter is not supported for ECI-type scaling groups or scaling groups with the economical mode enabled.

null

CustomPolicyARN

string

No

The Alibaba Cloud Resource Name (ARN) of the custom scale-in policy (Function). This parameter takes effect only when the first removal policy in RemovalPolicies is set to CustomPolicy.

acs:fc:cn-zhangjiakou:16145688****:services/ess_custom_terminate_policy.LATEST/functions/ess_custom_terminate_policy_name

ResourceGroupId

string

No

The ID of the resource group to which the newly created scaling group belongs.

Note

The newly created scaling group is added to the specified resource group. If you do not specify this parameter, the scaling group is added to the default resource group.

rg-123****

LoadBalancerConfig

array<object>

No

The list of Classic Load Balancer (CLB) (formerly SLB) load balancing configurations.

object

No

The list of Classic Load Balancer (CLB) (formerly SLB) load balancing configurations.

LoadBalancerId

string

No

The ID of the Classic Load Balancer (CLB) (formerly SLB) load balancing instance.

147b46d767c-cn-qingdao-cm5****

Weight

integer

No

The weight of the instance as a backend server after Auto Scaling adds the instance to the Classic Load Balancer (CLB) (formerly SLB) load balancing server group. A higher weight indicates that the instance is allocated more access requests. If the weight is 0, the instance does not receive access requests.

Valid values: 0 to 100.

10

HealthCheckTypes

array

No

The health check mode of the scaling group.

Note

You can specify multiple values for this parameter to enable multiple health check options. If the HealthCheckType parameter is specified, this parameter is ignored.

string

No

The health check modes of the scaling group. Valid values:

  • NONE: No health check is performed.

  • ECS: Health checks are performed on instances in the scaling group. This value applies to both ECS-type and ECI-type scaling groups.

  • LOAD_BALANCER: The health status of instances is determined based on load balancing health check results. CLB-type load balancing is not supported.

Default value: ECS.

ECS

DBInstance

array<object>

No

The list of databases associated with the scaling group.

object

No

The configuration of a database associated with the scaling group.

DBInstanceId

string

No

The database instance ID.

rm-m5eqju85s45mu0***

Type

string

No

The type of the database. Valid values:

  • RDS.

  • Redis.

  • MongoDB.

Default value: RDS.

RDS

AttachMode

string

No

The mode in which the scaling group is associated with the database. Valid values:

  • SecurityIp: IP whitelist mode. Scaled-out instances are automatically added to the IP whitelist of the database. Only RDS databases are supported.

  • SecurityGroup: Security group mode. The security group specified in the scaling configuration is added to the security group whitelist of the database, which allows instances in the security group to access the database.

SecurityIp

StopInstanceTimeout

integer

No

The timeout period for waiting for an ECS instance to be stopped during a scale-in process. Unit: seconds. Valid values: 30 to 240.

Note
  • This parameter takes effect only during scale-in processes when ScalingPolicy is set to release.

  • If this parameter is specified, the system waits up to the StopInstanceTimeout period for the instance to stop. After the timeout, the scale-in process continues regardless of whether the instance is stopped.

  • If this parameter is not specified, the system waits indefinitely for the instance to stop. The scale-in process continues only after the instance is stopped. If the instance fails to stop, the scale-in process is rolled back and the scaling activity fails.

60

CapacityOptions

object

No

The capacity options.

OnDemandBaseCapacity

integer

No

The minimum number of pay-as-you-go instances required in the scaling group. If the number of pay-as-you-go instances in the scaling group is less than this value, the system preferentially creates pay-as-you-go instances. Valid values: 0 to 1000.

If MultiAZPolicy is set to COMPOSABLE, the default value is 0.

30

OnDemandPercentageAboveBaseCapacity

integer

No

The percentage of pay-as-you-go instances among the instances that exceed the minimum number of pay-as-you-go instances specified by OnDemandBaseCapacity. Valid values: 0 to 100.

If MultiAZPolicy is set to COMPOSABLE, the default value is 100.

20

CompensateWithOnDemand

boolean

No

Specifies whether to automatically create pay-as-you-go instances to meet the required number of ECS instances when spot instances cannot be created due to price or inventory reasons. This parameter takes effect only when MultiAZPolicy is set to COST_OPTIMIZED. Valid values:

  • true: allowed.

  • false: not allowed.

Default value: true.

true

SpotAutoReplaceOnDemand

boolean

No

Specifies whether to use spot instances to replace pay-as-you-go instances when the pay-as-you-go percentage exceeds the OnDemandPercentageAboveBaseCapacity ratio after CompensateWithOnDemand is enabled. A common scenario is when spot instances are downgraded to pay-as-you-go instances due to spot inventory or pricing issues caused by CompensateWithOnDemand. To prevent pay-as-you-go instances from existing for an extended period, the system attempts to replace excess pay-as-you-go capacity with spot instances. Valid values:

  • true: Allowed.

  • false: Not allowed.

Default value: false.

false

PriceComparisonMode

string

No

The price comparison mode of the cost optimization policy for the scaling group. Valid values:

  • PricePerUnit: Compares prices based on the price per unit of capacity.

    The capacity of an instance in the scaling group equals the weight configured for the instance type. The default weight is 1, which means one ECS instance occupies a capacity of 1.

  • PricePerVCpu: Compares prices based on the price per vCPU.

Default value: PricePerUnit.

PricePerUnit

BalanceMode

string

No

The zone balancing mode. This parameter takes effect only when zone balancing is enabled. Valid values:

  • BalancedBestEffort: If resource creation fails in a zone, the system falls back to other zones to ensure best-effort resource delivery.

  • BalancedOnly: If resource creation fails in a zone, the system does not fall back to other zones. The scaling activity partially succeeds to prevent excessive imbalance of resources across zones.

Default value: BalancedBestEffort.

BalancedBestEffort

AutoRebalance

boolean

No

Specifies whether to enable automatic rebalancing for the scaling group. This parameter takes effect only when BalancedOnly is enabled for a zone-balanced scaling group. Valid values:

  • false: Disables automatic rebalancing.

  • true: Enables automatic rebalancing. The scaling group automatically detects capacity across zones. When zone capacity is imbalanced, the system proactively performs scale-in and scale-out operations to rebalance capacity across zones.

Default value: false.

false

Response elements

Element

Type

Description

Example

object

RequestId

string

The request ID.

473469C7-AA6F-4DC5-B3DB-A3DC0DE3****

ScalingGroupId

string

The scaling group ID.

asg-bp14wlu85wrpchm0****

Examples

Success response

JSON format

{
  "RequestId": "473469C7-AA6F-4DC5-B3DB-A3DC0DE3****",
  "ScalingGroupId": "asg-bp14wlu85wrpchm0****"
}

Error codes

HTTP status code

Error code

Error message

Description

404 ResourceNotAvailable.VPCNetwork The specified zone does not support vpc network or sold out.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.