CfnWarmPool

class aws_cdk.aws_autoscaling.CfnWarmPool(scope, id, *, auto_scaling_group_name, instance_reuse_policy=None, max_group_prepared_capacity=None, min_size=None, pool_state=None)

Bases: aws_cdk.core.CfnResource

A CloudFormation AWS::AutoScaling::WarmPool.

The AWS::AutoScaling::WarmPool resource creates a pool of pre-initialized EC2 instances that sits alongside the Auto Scaling group. Whenever your application needs to scale out, the Auto Scaling group can draw on the warm pool to meet its new desired capacity.

When you create a warm pool, you can define a minimum size. When your Auto Scaling group scales out and the size of the warm pool shrinks, Amazon EC2 Auto Scaling launches new instances into the warm pool to maintain its minimum size.

For more information, see Warm pools for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide . .. epigraph:

CloudFormation supports the ``UpdatePolicy`` attribute for Auto Scaling groups. During an update, if ``UpdatePolicy`` is set to ``AutoScalingRollingUpdate`` , CloudFormation replaces ``InService`` instances only. Instances in the warm pool are not replaced. The difference in which instances are replaced can potentially result in different instance configurations after the stack update completes. If ``UpdatePolicy`` is set to ``AutoScalingReplacingUpdate`` , you do not encounter this issue because CloudFormation replaces both the Auto Scaling group and the warm pool.
CloudformationResource

AWS::AutoScaling::WarmPool

Link

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-autoscaling-warmpool.html

ExampleMetadata

fixture=_generated

Example:

# The code below shows an example of how to instantiate this type.
# The values are placeholders you should change.
import aws_cdk.aws_autoscaling as autoscaling

cfn_warm_pool = autoscaling.CfnWarmPool(self, "MyCfnWarmPool",
    auto_scaling_group_name="autoScalingGroupName",

    # the properties below are optional
    instance_reuse_policy=autoscaling.CfnWarmPool.InstanceReusePolicyProperty(
        reuse_on_scale_in=False
    ),
    max_group_prepared_capacity=123,
    min_size=123,
    pool_state="poolState"
)

Create a new AWS::AutoScaling::WarmPool.

Parameters
  • scope (Construct) –

    • scope in which this resource is defined.

  • id (str) –

    • scoped id of the resource.

  • auto_scaling_group_name (str) – The name of the Auto Scaling group.

  • instance_reuse_policy (Union[IResolvable, InstanceReusePolicyProperty, Dict[str, Any], None]) – Indicates whether instances in the Auto Scaling group can be returned to the warm pool on scale in. The default is to terminate instances in the Auto Scaling group when the group scales in.

  • max_group_prepared_capacity (Union[int, float, None]) – Specifies the maximum number of instances that are allowed to be in the warm pool or in any state except Terminated for the Auto Scaling group. This is an optional property. Specify it only if you do not want the warm pool size to be determined by the difference between the group’s maximum capacity and its desired capacity. .. epigraph:: If a value for MaxGroupPreparedCapacity is not specified, Amazon EC2 Auto Scaling launches and maintains the difference between the group’s maximum capacity and its desired capacity. If you specify a value for MaxGroupPreparedCapacity , Amazon EC2 Auto Scaling uses the difference between the MaxGroupPreparedCapacity and the desired capacity instead. The size of the warm pool is dynamic. Only when MaxGroupPreparedCapacity and MinSize are set to the same value does the warm pool have an absolute size. If the desired capacity of the Auto Scaling group is higher than the MaxGroupPreparedCapacity , the capacity of the warm pool is 0, unless you specify a value for MinSize . To remove a value that you previously set, include the property but specify -1 for the value.

  • min_size (Union[int, float, None]) – Specifies the minimum number of instances to maintain in the warm pool. This helps you to ensure that there is always a certain number of warmed instances available to handle traffic spikes. Defaults to 0 if not specified.

  • pool_state (Optional[str]) – Sets the instance state to transition to after the lifecycle actions are complete. Default is Stopped .

Methods

add_deletion_override(path)

Syntactic sugar for addOverride(path, undefined).

Parameters

path (str) – The path of the value to delete.

Return type

None

add_depends_on(target)

Indicates that this resource depends on another resource and cannot be provisioned unless the other resource has been successfully provisioned.

This can be used for resources across stacks (or nested stack) boundaries and the dependency will automatically be transferred to the relevant scope.

Parameters

target (CfnResource) –

Return type

None

add_metadata(key, value)

Add a value to the CloudFormation Resource Metadata.

Parameters
  • key (str) –

  • value (Any) –

See

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/metadata-section-structure.html

Note that this is a different set of metadata from CDK node metadata; this metadata ends up in the stack template under the resource, whereas CDK node metadata ends up in the Cloud Assembly.

Return type

None

add_override(path, value)

Adds an override to the synthesized CloudFormation resource.

To add a property override, either use addPropertyOverride or prefix path with “Properties.” (i.e. Properties.TopicName).

If the override is nested, separate each nested level using a dot (.) in the path parameter. If there is an array as part of the nesting, specify the index in the path.

To include a literal . in the property name, prefix with a \. In most programming languages you will need to write this as "\\." because the \ itself will need to be escaped.

For example:

cfn_resource.add_override("Properties.GlobalSecondaryIndexes.0.Projection.NonKeyAttributes", ["myattribute"])
cfn_resource.add_override("Properties.GlobalSecondaryIndexes.1.ProjectionType", "INCLUDE")

would add the overrides Example:

"Properties": {
   "GlobalSecondaryIndexes": [
     {
       "Projection": {
         "NonKeyAttributes": [ "myattribute" ]
         ...
       }
       ...
     },
     {
       "ProjectionType": "INCLUDE"
       ...
     },
   ]
   ...
}

The value argument to addOverride will not be processed or translated in any way. Pass raw JSON values in here with the correct capitalization for CloudFormation. If you pass CDK classes or structs, they will be rendered with lowercased key names, and CloudFormation will reject the template.

Parameters
  • path (str) –

    • The path of the property, you can use dot notation to override values in complex types. Any intermdediate keys will be created as needed.

  • value (Any) –

    • The value. Could be primitive or complex.

Return type

None

add_property_deletion_override(property_path)

Adds an override that deletes the value of a property from the resource definition.

Parameters

property_path (str) – The path to the property.

Return type

None

add_property_override(property_path, value)

Adds an override to a resource property.

Syntactic sugar for addOverride("Properties.<...>", value).

Parameters
  • property_path (str) – The path of the property.

  • value (Any) – The value.

Return type

None

apply_removal_policy(policy=None, *, apply_to_update_replace_policy=None, default=None)

Sets the deletion policy of the resource based on the removal policy specified.

The Removal Policy controls what happens to this resource when it stops being managed by CloudFormation, either because you’ve removed it from the CDK application or because you’ve made a change that requires the resource to be replaced.

The resource can be deleted (RemovalPolicy.DESTROY), or left in your AWS account for data recovery and cleanup later (RemovalPolicy.RETAIN).

Parameters
  • policy (Optional[RemovalPolicy]) –

  • apply_to_update_replace_policy (Optional[bool]) – Apply the same deletion policy to the resource’s “UpdateReplacePolicy”. Default: true

  • default (Optional[RemovalPolicy]) – The default policy to apply in case the removal policy is not defined. Default: - Default value is resource specific. To determine the default value for a resoure, please consult that specific resource’s documentation.

Return type

None

get_att(attribute_name)

Returns a token for an runtime attribute of this resource.

Ideally, use generated attribute accessors (e.g. resource.arn), but this can be used for future compatibility in case there is no generated attribute.

Parameters

attribute_name (str) – The name of the attribute.

Return type

Reference

get_metadata(key)

Retrieve a value value from the CloudFormation Resource Metadata.

Parameters

key (str) –

See

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/metadata-section-structure.html

Note that this is a different set of metadata from CDK node metadata; this metadata ends up in the stack template under the resource, whereas CDK node metadata ends up in the Cloud Assembly.

Return type

Any

inspect(inspector)

Examines the CloudFormation resource and discloses attributes.

Parameters

inspector (TreeInspector) –

  • tree inspector to collect and process attributes.

Return type

None

override_logical_id(new_logical_id)

Overrides the auto-generated logical ID with a specific ID.

Parameters

new_logical_id (str) – The new logical ID to use for this stack element.

Return type

None

to_string()

Returns a string representation of this construct.

Return type

str

Returns

a string representation of this resource

Attributes

CFN_RESOURCE_TYPE_NAME = 'AWS::AutoScaling::WarmPool'
auto_scaling_group_name

The name of the Auto Scaling group.

Link

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-autoscaling-warmpool.html#cfn-autoscaling-warmpool-autoscalinggroupname

Return type

str

cfn_options

Options for this resource, such as condition, update policy etc.

Return type

ICfnResourceOptions

cfn_resource_type

AWS resource type.

Return type

str

creation_stack

return:

the stack trace of the point where this Resource was created from, sourced from the +metadata+ entry typed +aws:cdk:logicalId+, and with the bottom-most node +internal+ entries filtered.

Return type

List[str]

instance_reuse_policy

Indicates whether instances in the Auto Scaling group can be returned to the warm pool on scale in.

The default is to terminate instances in the Auto Scaling group when the group scales in.

Link

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-autoscaling-warmpool.html#cfn-autoscaling-warmpool-instancereusepolicy

Return type

Union[IResolvable, InstanceReusePolicyProperty, None]

logical_id

The logical ID for this CloudFormation stack element.

The logical ID of the element is calculated from the path of the resource node in the construct tree.

To override this value, use overrideLogicalId(newLogicalId).

Return type

str

Returns

the logical ID as a stringified token. This value will only get resolved during synthesis.

max_group_prepared_capacity

Specifies the maximum number of instances that are allowed to be in the warm pool or in any state except Terminated for the Auto Scaling group.

This is an optional property. Specify it only if you do not want the warm pool size to be determined by the difference between the group’s maximum capacity and its desired capacity. .. epigraph:

If a value for ``MaxGroupPreparedCapacity`` is not specified, Amazon EC2 Auto Scaling launches and maintains the difference between the group's maximum capacity and its desired capacity. If you specify a value for ``MaxGroupPreparedCapacity`` , Amazon EC2 Auto Scaling uses the difference between the ``MaxGroupPreparedCapacity`` and the desired capacity instead.

The size of the warm pool is dynamic. Only when ``MaxGroupPreparedCapacity`` and ``MinSize`` are set to the same value does the warm pool have an absolute size.

If the desired capacity of the Auto Scaling group is higher than the MaxGroupPreparedCapacity , the capacity of the warm pool is 0, unless you specify a value for MinSize . To remove a value that you previously set, include the property but specify -1 for the value.

Link

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-autoscaling-warmpool.html#cfn-autoscaling-warmpool-maxgrouppreparedcapacity

Return type

Union[int, float, None]

min_size

Specifies the minimum number of instances to maintain in the warm pool.

This helps you to ensure that there is always a certain number of warmed instances available to handle traffic spikes. Defaults to 0 if not specified.

Link

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-autoscaling-warmpool.html#cfn-autoscaling-warmpool-minsize

Return type

Union[int, float, None]

node

The construct tree node associated with this construct.

Return type

ConstructNode

pool_state

Sets the instance state to transition to after the lifecycle actions are complete.

Default is Stopped .

Link

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-autoscaling-warmpool.html#cfn-autoscaling-warmpool-poolstate

Return type

Optional[str]

ref

Return a string that will be resolved to a CloudFormation { Ref } for this element.

If, by any chance, the intrinsic reference of a resource is not a string, you could coerce it to an IResolvable through Lazy.any({ produce: resource.ref }).

Return type

str

stack

The stack in which this element is defined.

CfnElements must be defined within a stack scope (directly or indirectly).

Return type

Stack

Static Methods

classmethod is_cfn_element(x)

Returns true if a construct is a stack element (i.e. part of the synthesized cloudformation template).

Uses duck-typing instead of instanceof to allow stack elements from different versions of this library to be included in the same stack.

Parameters

x (Any) –

Return type

bool

Returns

The construct as a stack element or undefined if it is not a stack element.

classmethod is_cfn_resource(construct)

Check whether the given construct is a CfnResource.

Parameters

construct (IConstruct) –

Return type

bool

classmethod is_construct(x)

Return whether the given object is a Construct.

Parameters

x (Any) –

Return type

bool

InstanceReusePolicyProperty

class CfnWarmPool.InstanceReusePolicyProperty(*, reuse_on_scale_in=None)

Bases: object

A structure that specifies an instance reuse policy for the InstanceReusePolicy property of the AWS::AutoScaling::WarmPool resource.

For more information, see Warm pools for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide .

Parameters

reuse_on_scale_in (Union[bool, IResolvable, None]) – Specifies whether instances in the Auto Scaling group can be returned to the warm pool on scale in.

Link

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-autoscaling-warmpool-instancereusepolicy.html

ExampleMetadata

fixture=_generated

Example:

# The code below shows an example of how to instantiate this type.
# The values are placeholders you should change.
import aws_cdk.aws_autoscaling as autoscaling

instance_reuse_policy_property = autoscaling.CfnWarmPool.InstanceReusePolicyProperty(
    reuse_on_scale_in=False
)

Attributes

reuse_on_scale_in

Specifies whether instances in the Auto Scaling group can be returned to the warm pool on scale in.

Link

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-autoscaling-warmpool-instancereusepolicy.html#cfn-autoscaling-warmpool-instancereusepolicy-reuseonscalein

Return type

Union[bool, IResolvable, None]