Table of Contents

Class CfnWarmPool

Namespace
Amazon.CDK.AWS.AutoScaling
Assembly
Amazon.CDK.AWS.AutoScaling.dll

A CloudFormation AWS::AutoScaling::WarmPool.

public class CfnWarmPool : CfnResource, IInspectable
Inheritance
CfnWarmPool
Implements
IInspectable

Examples

// The code below shows an example of how to instantiate this type.
             // The values are placeholders you should change.
             using Amazon.CDK.AWS.AutoScaling;

             var cfnWarmPool = new CfnWarmPool(this, "MyCfnWarmPool", new CfnWarmPoolProps {
                 AutoScalingGroupName = "autoScalingGroupName",

                 // the properties below are optional
                 InstanceReusePolicy = new InstanceReusePolicyProperty {
                     ReuseOnScaleIn = false
                 },
                 MaxGroupPreparedCapacity = 123,
                 MinSize = 123,
                 PoolState = "poolState"
             });

Remarks

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 .

CloudFormation supports the <code>UpdatePolicy</code> attribute for Auto Scaling groups. During an update, if <code>UpdatePolicy</code> is set to <code>AutoScalingRollingUpdate</code> , CloudFormation replaces <code>InService</code> 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 <code>UpdatePolicy</code> is set to <code>AutoScalingReplacingUpdate</code> , 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

Constructors

CfnWarmPool(Construct, string, ICfnWarmPoolProps)

Create a new AWS::AutoScaling::WarmPool.

public CfnWarmPool(Construct scope, string id, ICfnWarmPoolProps props)

Parameters

scope Construct
  • scope in which this resource is defined.
id string
  • scoped id of the resource.
props ICfnWarmPoolProps
  • resource properties.

Properties

AutoScalingGroupName

The name of the Auto Scaling group.

public virtual string AutoScalingGroupName { get; set; }

Property Value

string

Remarks

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

CFN_RESOURCE_TYPE_NAME

The CloudFormation resource type name for this resource class.

public static string CFN_RESOURCE_TYPE_NAME { get; }

Property Value

string

CfnProperties 

protected override IDictionary<string, object> CfnProperties { get; }

Property Value

IDictionary<string, object>

InstanceReusePolicy

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

public virtual object? InstanceReusePolicy { get; set; }

Property Value

object

Remarks

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

MaxGroupPreparedCapacity

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.

public virtual double? MaxGroupPreparedCapacity { get; set; }

Property Value

double?

Remarks

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.

If a value for <code>MaxGroupPreparedCapacity</code> 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 <code>MaxGroupPreparedCapacity</code> , Amazon EC2 Auto Scaling uses the difference between the <code>MaxGroupPreparedCapacity</code> 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

MinSize

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

public virtual double? MinSize { get; set; }

Property Value

double?

Remarks

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

PoolState

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

public virtual string? PoolState { get; set; }

Property Value

string

Remarks

Default is Stopped .

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

Methods

Inspect(TreeInspector)

Examines the CloudFormation resource and discloses attributes.

public virtual void Inspect(TreeInspector inspector)

Parameters

inspector TreeInspector
  • tree inspector to collect and process attributes.

RenderProperties(IDictionary<string, object>) 

protected override IDictionary<string, object> RenderProperties(IDictionary<string, object> props)

Parameters

props IDictionary<string, object>

Returns

IDictionary<string, object>