AWS::AutoScaling::AutoScalingGroup – AWS CloudFormation

The name of the Auto Scaling group. This name must be unique per Region per account.

The name can contain any ASCII character 33 to 126 including most punctuation
characters, digits, and upper and lowercased letters.

Note

You cannot use a colon (:) in the name.

Required: No

Type: String

Update requires: Replacement

A list of Availability Zones where instances in the Auto Scaling group can be created. Used
for launching into the default VPC subnet in each Availability Zone when not using the
VPCZoneIdentifier property, or for attaching a network interface when
an existing network interface ID is specified in a launch template.

Required: No

Type: List of String

Update requires: No interruption

Indicates whether Capacity Rebalancing is enabled. Otherwise, Capacity Rebalancing is
disabled. When you turn on Capacity Rebalancing, Amazon EC2 Auto Scaling attempts to launch a Spot
Instance whenever Amazon EC2 notifies that a Spot Instance is at an elevated risk of
interruption. After launching a new instance, it then terminates an old instance. For
more information, see Use Capacity
Rebalancing to handle Amazon EC2 Spot Interruptions in the in the Amazon EC2 Auto Scaling User Guide.

Required: No

Type: Boolean

Update requires: No interruption

Reserved.

Required: No

Type: String

Update requires: No interruption

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.

Default: 300 seconds

Required: No

Type: String

Update requires: No interruption

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 of 0 or other
nominal value.

Default: None

Required: No

Type: Integer

Update requires: No interruption

The desired capacity is the initial capacity of the Auto Scaling group at the time of its
creation and the capacity it attempts to maintain. It can scale beyond this capacity if you
configure automatic scaling.

The 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. If you do not specify a desired capacity when creating
the stack, the default is the minimum size of the group.

CloudFormation marks the Auto Scaling group as successful (by setting its status to
CREATE_COMPLETE) when the desired capacity is reached. However, if a maximum Spot price is set
in the launch template or launch configuration that you specified, then desired capacity is
not used as a criteria for success. Whether your request is fulfilled depends on Spot Instance
capacity and your maximum price.

Required: No

Type: String

Update requires: No interruption

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 Creating
an Auto Scaling 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

Required: No

Type: String

Update requires: No interruption

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.

Default: 0 seconds

Required: No

Type: Integer

Update requires: No interruption

A comma-separated value string of one or more health check types.

The valid values are EC2, ELB, and VPC_LATTICE.
EC2 is the default health check and cannot be disabled. For more
information, see Health checks for Auto Scaling
instances in the Amazon EC2 Auto Scaling User Guide.

Only specify EC2 if you must clear a value that was previously
set.

Required: No

Type: String

Update requires: No interruption

The ID of the instance used to base the launch configuration on. For more information, see
Create an Auto Scaling group using an EC2 instance in the Amazon EC2 Auto
Scaling User Guide.

If you specify LaunchTemplate, MixedInstancesPolicy, or
LaunchConfigurationName, don’t specify InstanceId.

Required: No

Type: String

Update requires: Replacement

The name of the launch configuration to use to launch instances.

Required only if you don’t specify LaunchTemplate,
MixedInstancesPolicy, or InstanceId.

Required: No

Type: String

Update requires: No interruption

Information used to specify the launch template and version to use to launch instances.
You can alternatively associate a launch template to the Auto Scaling group by specifying a
MixedInstancesPolicy. For more information about creating launch templates, see
Create a launch template for an Auto Scaling group in the Amazon EC2 Auto
Scaling User Guide.

If you omit this property, you must specify MixedInstancesPolicy,
LaunchConfigurationName, or InstanceId.

Required: No

Type: LaunchTemplateSpecification

Update requires: No interruption

One or more lifecycle hooks to add to the Auto Scaling group before instances are
launched.

Required: No

Type: List of LifecycleHookSpecification

Update requires: No interruption

A list of Classic Load Balancers associated with this Auto Scaling group. For Application Load Balancers, Network Load Balancers, and Gateway Load Balancers,
specify the TargetGroupARNs property instead.

Required: No

Type: List of String

Update requires: No interruption

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). For more information, see Replacing Auto Scaling instances based on maximum instance lifetime in the
Amazon EC2 Auto Scaling User Guide.

Required: No

Type: Integer

Update requires: No interruption

The maximum size of the 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 above MaxSize by more than your largest instance
weight (weights that define how many units each instance contributes to the desired
capacity of the group).

Required: Yes

Type: String

Update requires: No interruption

Enables the monitoring of group metrics of an Auto Scaling group. By default, these
metrics are disabled.

Required: No

Type: List of MetricsCollection

Update requires: No interruption

The minimum size of the group.

Required: Yes

Type: String

Update requires: No interruption

An embedded object that specifies a mixed instances policy.

The policy includes properties that not only define the distribution of On-Demand
Instances and Spot Instances, the maximum price to pay for Spot Instances (optional), and how
the Auto Scaling group allocates instance types to fulfill On-Demand and Spot capacities, but
also the properties that specify the instance configuration information—the launch template
and instance types. The policy can also include a weight for each instance type and different
launch templates for individual instance types.

For more information, see Auto Scaling
groups with multiple instance types and purchase options in the Amazon EC2
Auto Scaling User Guide.

Required: No

Type: MixedInstancesPolicy

Update requires: No interruption

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 Using
instance scale-in protection in the
Amazon EC2 Auto Scaling User Guide.

Required: No

Type: Boolean

Update requires: No interruption

Configures an Auto Scaling group to send notifications when specified events take
place.

Required: No

Type: List of NotificationConfiguration

Update requires: No interruption

The name of the 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.

Required: No

Type: String

Update requires: No interruption

The Amazon Resource Name (ARN) of the service-linked role that the Auto Scaling group uses to
call other AWS service on your behalf. By default, Amazon EC2 Auto Scaling uses a service-linked role
named AWSServiceRoleForAutoScaling, which it creates if it does not exist.
For more information, see Service-linked
roles in the Amazon EC2 Auto Scaling User Guide.

Required: No

Type: String

Update requires: No interruption

One or more tags. You can tag your Auto Scaling group and propagate the tags to the Amazon EC2
instances it launches. Tags are not propagated to Amazon EBS volumes. To add tags to Amazon EBS
volumes, specify the tags in a launch template but use caution. If the launch template
specifies an instance tag with a key that is also specified for the Auto Scaling group, Amazon EC2 Auto Scaling
overrides the value of that instance tag with the value specified by the Auto Scaling group. For
more information, see Tag Auto Scaling groups and
instances in the Amazon EC2 Auto Scaling User Guide.

Required: No

Type: List of TagProperty

Update requires: No interruption

The Amazon Resource Names (ARN) of the Elastic Load Balancing target groups to associate with the Auto Scaling
group. Instances are registered as targets with the target groups. The target groups
receive incoming traffic and route requests to one or more registered targets. For more
information, see Use Elastic Load Balancing to
distribute traffic across the instances in your Auto Scaling group in the
Amazon EC2 Auto Scaling User Guide.

Required: No

Type: List of String

Update requires: No interruption

A policy or a list of policies that are used to select the instance to terminate.
These policies are executed in the order that you list them. For more information, see
Work with
Amazon EC2 Auto Scaling termination policies 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

Required: No

Type: List of String

Update requires: No interruption

A list of subnet IDs for a virtual private cloud (VPC) where instances in the Auto Scaling
group can be created.

If this resource specifies public subnets and is also in a VPC that is defined in the same
stack template, you must use the DependsOn
attribute to declare a dependency on the VPC-gateway attachment.

Note

When you update VPCZoneIdentifier, this retains the same Auto Scaling group
and replaces old instances with new ones, according to the specified subnets. You can
optionally specify how CloudFormation handles these updates by using an UpdatePolicy
attribute.

Required to launch instances into a nondefault VPC. If you specify
VPCZoneIdentifier with AvailabilityZones, the subnets that you
specify for this property must reside in those Availability Zones.

Required: Conditional

Type: List of String

Update requires: Some interruptions