UpdateAutoScalingGroup
We strongly recommend that all Auto Scaling groups use launch templates to ensure full functionality for Amazon EC2 Auto Scaling and Amazon EC2.
Updates the configuration for the specified Auto Scaling group.
To update an Auto Scaling group, specify the name of the group and the property that you want to change. Any properties that you don't specify are not changed by this update request. The new settings take effect on any scaling activities after this call returns.
If you associate a new launch configuration or template with an Auto Scaling group, all new instances will get the updated configuration. Existing instances continue to run with the configuration that they were originally launched with. When you update a group to specify a mixed instances policy instead of a launch configuration or template, existing instances may be replaced to match the new purchasing options that you specified in the policy. For example, if the group currently has 100% On-Demand capacity and the policy specifies 50% Spot capacity, this means that half of your instances will be gradually terminated and relaunched as Spot Instances. When replacing instances, Amazon EC2 Auto Scaling launches new instances before terminating the old ones, so that updating your group does not compromise the performance or availability of your application.
Note the following about changing DesiredCapacity
, MaxSize
,
or MinSize
:
-
If a scale-in activity occurs as a result of a new
DesiredCapacity
value that is lower than the current size of the group, the Auto Scaling group uses its termination policy to determine which instances to terminate. -
If you specify a new value for
MinSize
without specifying a value forDesiredCapacity
, and the newMinSize
is larger than the current size of the group, this sets the group'sDesiredCapacity
to the newMinSize
value. -
If you specify a new value for
MaxSize
without specifying a value forDesiredCapacity
, and the newMaxSize
is smaller than the current size of the group, this sets the group'sDesiredCapacity
to the newMaxSize
value.
To see which properties have been set, call the DescribeAutoScalingGroups API. To view the scaling policies for an Auto Scaling group, call the DescribePolicies API. If the group has scaling policies, you can update them by calling the PutScalingPolicy API.
Request Parameters
For information about the parameters that are common to all actions, see Common Parameters.
- AutoScalingGroupName
-
The name of the Auto Scaling group.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: Yes
- AvailabilityZones.member.N
-
One or more Availability Zones for the group.
Type: Array of strings
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: No
- CapacityRebalance
-
Enables or disables Capacity Rebalancing. For more information, see Use Capacity Rebalancing to handle Amazon EC2 Spot Interruptions in the Amazon EC2 Auto Scaling User Guide.
Type: Boolean
Required: No
- Context
-
Reserved.
Type: String
Required: No
- DefaultCooldown
-
Only needed if you use simple scaling policies.
The amount of time, in seconds, between one scaling activity ending and another one starting due to simple scaling policies. For more information, see Scaling cooldowns for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide.
Type: Integer
Required: No
- DefaultInstanceWarmup
-
The amount of time, in seconds, until a new instance is considered to have finished initializing and resource consumption to become stable after it enters the
InService
state.During an instance refresh, Amazon EC2 Auto Scaling waits for the warm-up period after it replaces an instance before it moves on to replacing the next instance. Amazon EC2 Auto Scaling also waits for the warm-up period before aggregating the metrics for new instances with existing instances in the Amazon CloudWatch metrics that are used for scaling, resulting in more reliable usage data. For more information, see Set the default instance warmup for an Auto Scaling group in the Amazon EC2 Auto Scaling User Guide.
Important
To manage various warm-up settings at the group level, we recommend that you set the default instance warmup, even if it is set to 0 seconds. To remove a value that you previously set, include the property but specify
-1
for the value. However, we strongly recommend keeping the default instance warmup enabled by specifying a value of0
or other nominal value.Type: Integer
Required: No
- DesiredCapacity
-
The desired capacity is the initial capacity of the Auto Scaling group after this operation completes and the capacity it attempts to maintain. This number must be greater than or equal to the minimum size of the group and less than or equal to the maximum size of the group.
Type: Integer
Required: No
- DesiredCapacityType
-
The unit of measurement for the value specified for desired capacity. Amazon EC2 Auto Scaling supports
DesiredCapacityType
for attribute-based instance type selection only. For more information, see Create a mixed instances group using attribute-based instance type selection in the Amazon EC2 Auto Scaling User Guide.By default, Amazon EC2 Auto Scaling specifies
units
, which translates into number of instances.Valid values:
units
|vcpu
|memory-mib
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: No
- HealthCheckGracePeriod
-
The amount of time, in seconds, that Amazon EC2 Auto Scaling waits before checking the health status of an EC2 instance that has come into service and marking it unhealthy due to a failed health check. This is useful if your instances do not immediately pass their health checks after they enter the
InService
state. For more information, see Set the health check grace period for an Auto Scaling group in the Amazon EC2 Auto Scaling User Guide.Type: Integer
Required: No
- HealthCheckType
-
A comma-separated value string of one or more health check types.
The valid values are
EC2
,EBS
,ELB
, andVPC_LATTICE
.EC2
is the default health check and cannot be disabled. For more information, see Health checks for instances in an Auto Scaling group in the Amazon EC2 Auto Scaling User Guide.Only specify
EC2
if you must clear a value that was previously set.Type: String
Length Constraints: Minimum length of 1. Maximum length of 32.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: No
- InstanceMaintenancePolicy
-
An instance maintenance policy. For more information, see Set instance maintenance policy in the Amazon EC2 Auto Scaling User Guide.
Type: InstanceMaintenancePolicy object
Required: No
- LaunchConfigurationName
-
The name of the launch configuration. If you specify
LaunchConfigurationName
in your update request, you can't specifyLaunchTemplate
orMixedInstancesPolicy
.Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: No
- LaunchTemplate
-
The launch template and version to use to specify the updates. If you specify
LaunchTemplate
in your update request, you can't specifyLaunchConfigurationName
orMixedInstancesPolicy
.Type: LaunchTemplateSpecification object
Required: No
- MaxInstanceLifetime
-
The maximum amount of time, in seconds, that an instance can be in service. The default is null. If specified, the value must be either 0 or a number equal to or greater than 86,400 seconds (1 day). To clear a previously set value, specify a new value of 0. For more information, see Replacing Auto Scaling instances based on maximum instance lifetime in the Amazon EC2 Auto Scaling User Guide.
Type: Integer
Required: No
- MaxSize
-
The maximum size of the Auto Scaling group.
Note
With a mixed instances policy that uses instance weighting, Amazon EC2 Auto Scaling may need to go above
MaxSize
to meet your capacity requirements. In this event, Amazon EC2 Auto Scaling will never go aboveMaxSize
by more than your largest instance weight (weights that define how many units each instance contributes to the desired capacity of the group).Type: Integer
Required: No
- MinSize
-
The minimum size of the Auto Scaling group.
Type: Integer
Required: No
- MixedInstancesPolicy
-
The mixed instances policy. For more information, see Auto Scaling groups with multiple instance types and purchase options in the Amazon EC2 Auto Scaling User Guide.
Type: MixedInstancesPolicy object
Required: No
- NewInstancesProtectedFromScaleIn
-
Indicates whether newly launched instances are protected from termination by Amazon EC2 Auto Scaling when scaling in. For more information about preventing instances from terminating on scale in, see Use instance scale-in protection in the Amazon EC2 Auto Scaling User Guide.
Type: Boolean
Required: No
- PlacementGroup
-
The name of an existing placement group into which to launch your instances. For more information, see Placement groups in the Amazon EC2 User Guide for Linux Instances.
Note
A cluster placement group is a logical grouping of instances within a single Availability Zone. You cannot specify multiple Availability Zones and a cluster placement group.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 255.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: No
- ServiceLinkedRoleARN
-
The Amazon Resource Name (ARN) of the service-linked role that the Auto Scaling group uses to call other Amazon Web Services on your behalf. For more information, see Service-linked roles in the Amazon EC2 Auto Scaling User Guide.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1600.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: No
- TerminationPolicies.member.N
-
A policy or a list of policies that are used to select the instances to terminate. The policies are executed in the order that you list them. For more information, see Configure termination policies for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide.
Valid values:
Default
|AllocationStrategy
|ClosestToNextInstanceHour
|NewestInstance
|OldestInstance
|OldestLaunchConfiguration
|OldestLaunchTemplate
|arn:aws:lambda:region:account-id:function:my-function:my-alias
Type: Array of strings
Length Constraints: Minimum length of 1. Maximum length of 1600.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: No
- VPCZoneIdentifier
-
A comma-separated list of subnet IDs for a virtual private cloud (VPC). If you specify
VPCZoneIdentifier
withAvailabilityZones
, the subnets that you specify must reside in those Availability Zones.Type: String
Length Constraints: Minimum length of 1. Maximum length of 5000.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Required: No
Errors
For information about the errors that are common to all actions, see Common Errors.
- ResourceContention
-
You already have a pending update to an Amazon EC2 Auto Scaling resource (for example, an Auto Scaling group, instance, or load balancer).
HTTP Status Code: 500
- ScalingActivityInProgress
-
The operation can't be performed because there are scaling activities in progress.
HTTP Status Code: 400
- ServiceLinkedRoleFailure
-
The service-linked role is not yet ready for use.
HTTP Status Code: 500
Examples
Example 1: Update the health check settings of an existing Auto Scaling group
This example updates the health check settings for the Auto Scaling group
my-asg
.
Sample Request
https://autoscaling.amazonaws.com/?Action=UpdateAutoScalingGroup
&AutoScalingGroupName=my-asg
&HealthCheckType=ELB
&HealthCheckGracePeriod=300
&Version=2011-01-01
&AUTHPARAMS
Example 2: Update the VPC subnets of an existing Auto Scaling group
This example updates the VPC subnets for the Auto Scaling group
my-asg
.
Sample Request
https://autoscaling.amazonaws.com/?Action=UpdateAutoScalingGroup
&AutoScalingGroupName=my-asg
&VPCZoneIdentifier=subnet-057fa0918fEXAMPLE%2Csubnet-610acd08EXAMPLE%2Csubnet-530fc83aEXAMPLE
&Version=2011-01-01
&AUTHPARAMS
See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following: