Auto Scaling

Creates or updates a lifecycle hook for the specified Auto Scaling group. Lifecycle hooks let you create solutions that are aware of events in the Auto Scaling instance lifecycle, and then perform a custom action on instances when the corresponding lifecycle event occurs. This step is a part of the procedure for adding a lifecycle hook to an Auto Scaling group: (Optional) Create a launch template or launch configuration with a user data script that runs while an instance is in a wait state due to a lifecycle hook. (Optional) Create a Lambda function and a rule that allows Amazon EventBridge to invoke your Lambda function when an instance is put into a wait state due to a lifecycle hook. (Optional) Create a notification target and an IAM role. The target can be either an Amazon SQS queue or an Amazon SNS topic. The role allows Amazon EC2 Auto Scaling to publish lifecycle notifications to the target. Create the lifecycle hook. Specify whether the hook is used when the instances launch or terminate. If you need more time, record the lifecycle action heartbeat to keep the instance in a wait state using the RecordLifecycleActionHeartbeat API call. If you finish before the timeout period ends, send a callback by using the CompleteLifecycleAction API call. For more information, see Amazon EC2 Auto Scaling lifecycle hooks in the Amazon EC2 Auto Scaling User Guide. If you exceed your maximum limit of lifecycle hooks, which by default is 50 per Auto Scaling group, the call fails. You can view the lifecycle hooks for an Auto Scaling group using the DescribeLifecycleHooks API call. If you are no longer using a lifecycle hook, you can delete it by calling the DeleteLifecycleHook API.

Configures an Auto Scaling group to send notifications when specified events take place. Subscribers to the specified topic can have messages delivered to an endpoint such as a web server or an email address. This configuration overwrites any existing configuration. For more information, see Getting Amazon SNS notifications when your Auto Scaling group scales in the Amazon EC2 Auto Scaling User Guide. If you exceed your maximum limit of SNS topics, which is 10 per Auto Scaling group, the call fails.

Creates or updates a scaling policy for an Auto Scaling group. Scaling policies are used to scale an Auto Scaling group based on configurable metrics. If no policies are defined, the dynamic scaling and predictive scaling features are not used. For more information about using dynamic scaling, see Target tracking scaling policies and Step and simple scaling policies in the Amazon EC2 Auto Scaling User Guide. For more information about using predictive scaling, see Predictive scaling for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide. You can view the scaling policies for an Auto Scaling group using the DescribePolicies API call. If you are no longer using a scaling policy, you can delete it by calling the DeletePolicy API.

Creates or updates a scheduled scaling action for an Auto Scaling group. For more information, see Scheduled scaling in the Amazon EC2 Auto Scaling User Guide. You can view the scheduled actions for an Auto Scaling group using the DescribeScheduledActions API call. If you are no longer using a scheduled action, you can delete it by calling the DeleteScheduledAction API. If you try to schedule your action in the past, Amazon EC2 Auto Scaling returns an error message.

Creates or updates a warm pool for the specified Auto Scaling group. A warm pool is 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. For more information and example configurations, see Warm pools for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide. This operation must be called from the Region in which the Auto Scaling group was created. This operation cannot be called on an Auto Scaling group that has a mixed instances policy or a launch template or launch configuration that requests Spot Instances. You can view the instances in the warm pool using the DescribeWarmPool API call. If you are no longer using a warm pool, you can delete it by calling the DeleteWarmPool API.

Records a heartbeat for the lifecycle action associated with the specified token or instance. This extends the timeout by the length of time defined using the PutLifecycleHook API call. This step is a part of the procedure for adding a lifecycle hook to an Auto Scaling group: (Optional) Create a launch template or launch configuration with a user data script that runs while an instance is in a wait state due to a lifecycle hook. (Optional) Create a Lambda function and a rule that allows Amazon EventBridge to invoke your Lambda function when an instance is put into a wait state due to a lifecycle hook. (Optional) Create a notification target and an IAM role. The target can be either an Amazon SQS queue or an Amazon SNS topic. The role allows Amazon EC2 Auto Scaling to publish lifecycle notifications to the target. Create the lifecycle hook. Specify whether the hook is used when the instances launch or terminate. If you need more time, record the lifecycle action heartbeat to keep the instance in a wait state. If you finish before the timeout period ends, send a callback by using the CompleteLifecycleAction API call. For more information, see Amazon EC2 Auto Scaling lifecycle hooks in the Amazon EC2 Auto Scaling User Guide.

Resumes the specified suspended auto scaling processes, or all suspended process, for the specified Auto Scaling group. For more information, see Suspending and resuming scaling processes in the Amazon EC2 Auto Scaling User Guide.

Cancels an instance refresh that is in progress and rolls back any changes that it made. Amazon EC2 Auto Scaling replaces any instances that were replaced during the instance refresh. This restores your Auto Scaling group to the configuration that it was using before the start of the instance refresh. This operation is part of the instance refresh feature in Amazon EC2 Auto Scaling, which helps you update instances in your Auto Scaling group after you make configuration changes. A rollback is not supported in the following situations: There is no desired configuration specified for the instance refresh. The Auto Scaling group has a launch template that uses an Amazon Web Services Systems Manager parameter instead of an AMI ID for the ImageId property. The Auto Scaling group uses the launch template's $Latest or $Default version. When you receive a successful response from this operation, Amazon EC2 Auto Scaling immediately begins replacing instances. You can check the status of this operation through the DescribeInstanceRefreshes API operation.

Sets the size of the specified Auto Scaling group. 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. For more information, see Manual scaling in the Amazon EC2 Auto Scaling User Guide.

Sets the health status of the specified instance. For more information, see Health checks for Auto Scaling instances in the Amazon EC2 Auto Scaling User Guide.

Updates the instance protection settings of the specified instances. This operation cannot be called on instances in a warm pool. For more information about preventing instances that are part of an Auto Scaling group from terminating on scale in, see Using instance scale-in protection in the Amazon EC2 Auto Scaling User Guide. If you exceed your maximum limit of instance IDs, which is 50 per Auto Scaling group, the call fails.

Starts an instance refresh. During an instance refresh, Amazon EC2 Auto Scaling performs a rolling update of instances in an Auto Scaling group. Instances are terminated first and then replaced, which temporarily reduces the capacity available within your Auto Scaling group. This operation is part of the instance refresh feature in Amazon EC2 Auto Scaling, which helps you update instances in your Auto Scaling group. This feature is helpful, for example, when you have a new AMI or a new user data script. You just need to create a new launch template that specifies the new AMI or user data script. Then start an instance refresh to immediately begin the process of updating instances in the group. If successful, the request's response contains a unique ID that you can use to track the progress of the instance refresh. To query its status, call the DescribeInstanceRefreshes API. To describe the instance refreshes that have already run, call the DescribeInstanceRefreshes API. To cancel an instance refresh that is in progress, use the CancelInstanceRefresh API. An instance refresh might fail for several reasons, such as EC2 launch failures, misconfigured health checks, or not ignoring or allowing the termination of instances that are in Standby state or protected from scale in. You can monitor for failed EC2 launches using the scaling activities. To find the scaling activities, call the DescribeScalingActivities API. If you enable auto rollback, your Auto Scaling group will be rolled back automatically when the instance refresh fails. You can enable this feature before starting an instance refresh by specifying the AutoRollback property in the instance refresh preferences. Otherwise, to roll back an instance refresh before it finishes, use the RollbackInstanceRefresh API.

Suspends the specified auto scaling processes, or all processes, for the specified Auto Scaling group. If you suspend either the Launch or Terminate process types, it can prevent other process types from functioning properly. For more information, see Suspending and resuming scaling processes in the Amazon EC2 Auto Scaling User Guide. To resume processes that have been suspended, call the ResumeProcesses API.

Terminates the specified instance and optionally adjusts the desired group size. This operation cannot be called on instances in a warm pool. This call simply makes a termination request. The instance is not terminated immediately. When an instance is terminated, the instance status changes to terminated. You can't connect to or start an instance after you've terminated it. If you do not specify the option to decrement the desired capacity, Amazon EC2 Auto Scaling launches instances to replace the ones that are terminated. By default, Amazon EC2 Auto Scaling balances instances across all Availability Zones. If you decrement the desired capacity, your Auto Scaling group can become unbalanced between Availability Zones. Amazon EC2 Auto Scaling tries to rebalance the group, and rebalancing might terminate instances in other zones. For more information, see Rebalancing activities in the Amazon EC2 Auto Scaling User Guide.

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 for DesiredCapacity, and the new MinSize is larger than the current size of the group, this sets the group's DesiredCapacity to the new MinSize value. If you specify a new value for MaxSize without specifying a value for DesiredCapacity, and the new MaxSize is smaller than the current size of the group, this sets the group's DesiredCapacity to the new MaxSize 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.

Attaches one or more EC2 instances to the specified Auto Scaling group. When you attach instances, Amazon EC2 Auto Scaling increases the desired capacity of the group by the number of instances being attached. If the number of instances being attached plus the desired capacity of the group exceeds the maximum size of the group, the operation fails. If there is a Classic Load Balancer attached to your Auto Scaling group, the instances are also registered with the load balancer. If there are target groups attached to your Auto Scaling group, the instances are also registered with the target groups. For more information, see Attach EC2 instances to your Auto Scaling group in the Amazon EC2 Auto Scaling User Guide.

This API operation is superseded by AttachTrafficSources, which can attach multiple traffic sources types. We recommend using AttachTrafficSources to simplify how you manage traffic sources. However, we continue to support AttachLoadBalancerTargetGroups. You can use both the original AttachLoadBalancerTargetGroups API operation and AttachTrafficSources on the same Auto Scaling group. Attaches one or more target groups to the specified Auto Scaling group. This operation is used with the following load balancer types: Application Load Balancer - Operates at the application layer (layer 7) and supports HTTP and HTTPS. Network Load Balancer - Operates at the transport layer (layer 4) and supports TCP, TLS, and UDP. Gateway Load Balancer - Operates at the network layer (layer 3). To describe the target groups for an Auto Scaling group, call the DescribeLoadBalancerTargetGroups API. To detach the target group from the Auto Scaling group, call the DetachLoadBalancerTargetGroups API. This operation is additive and does not detach existing target groups or Classic Load Balancers from the Auto Scaling group. 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.

This API operation is superseded by AttachTrafficSources, which can attach multiple traffic sources types. We recommend using AttachTrafficSources to simplify how you manage traffic sources. However, we continue to support AttachLoadBalancers. You can use both the original AttachLoadBalancers API operation and AttachTrafficSources on the same Auto Scaling group. Attaches one or more Classic Load Balancers to the specified Auto Scaling group. Amazon EC2 Auto Scaling registers the running instances with these Classic Load Balancers. To describe the load balancers for an Auto Scaling group, call the DescribeLoadBalancers API. To detach a load balancer from the Auto Scaling group, call the DetachLoadBalancers API. This operation is additive and does not detach existing Classic Load Balancers or target groups from the Auto Scaling group. 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.

Attaches one or more traffic sources to the specified Auto Scaling group. You can use any of the following as traffic sources for an Auto Scaling group: Application Load Balancer Classic Load Balancer Gateway Load Balancer Network Load Balancer VPC Lattice This operation is additive and does not detach existing traffic sources from the Auto Scaling group. After the operation completes, use the DescribeTrafficSources API to return details about the state of the attachments between traffic sources and your Auto Scaling group. To detach a traffic source from the Auto Scaling group, call the DetachTrafficSources API.

Deletes one or more scheduled actions for the specified Auto Scaling group.

Creates or updates one or more scheduled scaling actions for an Auto Scaling group.

Cancels an instance refresh or rollback that is in progress. If an instance refresh or rollback is not in progress, an ActiveInstanceRefreshNotFound error occurs. This operation is part of the instance refresh feature in Amazon EC2 Auto Scaling, which helps you update instances in your Auto Scaling group after you make configuration changes. When you cancel an instance refresh, this does not roll back any changes that it made. Use the RollbackInstanceRefresh API to roll back instead.

Completes the lifecycle action for the specified token or instance with the specified result. This step is a part of the procedure for adding a lifecycle hook to an Auto Scaling group: (Optional) Create a launch template or launch configuration with a user data script that runs while an instance is in a wait state due to a lifecycle hook. (Optional) Create a Lambda function and a rule that allows Amazon EventBridge to invoke your Lambda function when an instance is put into a wait state due to a lifecycle hook. (Optional) Create a notification target and an IAM role. The target can be either an Amazon SQS queue or an Amazon SNS topic. The role allows Amazon EC2 Auto Scaling to publish lifecycle notifications to the target. Create the lifecycle hook. Specify whether the hook is used when the instances launch or terminate. If you need more time, record the lifecycle action heartbeat to keep the instance in a wait state. If you finish before the timeout period ends, send a callback by using the CompleteLifecycleAction API call. For more information, see Amazon EC2 Auto Scaling lifecycle hooks in the Amazon EC2 Auto Scaling User Guide.

We strongly recommend using a launch template when calling this operation to ensure full functionality for Amazon EC2 Auto Scaling and Amazon EC2. Creates an Auto Scaling group with the specified name and attributes. If you exceed your maximum limit of Auto Scaling groups, the call fails. To query this limit, call the DescribeAccountLimits API. For information about updating this limit, see Quotas for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide. For introductory exercises for creating an Auto Scaling group, see Getting started with Amazon EC2 Auto Scaling and Tutorial: Set up a scaled and load-balanced application in the Amazon EC2 Auto Scaling User Guide. For more information, see Auto Scaling groups in the Amazon EC2 Auto Scaling User Guide. Every Auto Scaling group has three size properties (DesiredCapacity, MaxSize, and MinSize). Usually, you set these sizes based on a specific number of instances. However, if you configure a mixed instances policy that defines weights for the instance types, you must specify these sizes with the same units that you use for weighting instances.

Creates a launch configuration. If you exceed your maximum limit of launch configurations, the call fails. To query this limit, call the DescribeAccountLimits API. For information about updating this limit, see Quotas for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide. For more information, see Launch configurations in the Amazon EC2 Auto Scaling User Guide. Amazon EC2 Auto Scaling configures instances launched as part of an Auto Scaling group using either a launch template or a launch configuration. We strongly recommend that you do not use launch configurations. They do not provide full functionality for Amazon EC2 Auto Scaling or Amazon EC2. For information about using launch templates, see Launch templates in the Amazon EC2 Auto Scaling User Guide.

Creates or updates tags for the specified Auto Scaling group. When you specify a tag with a key that already exists, the operation overwrites the previous tag definition, and you do not get an error message. For more information, see Tag Auto Scaling groups and instances in the Amazon EC2 Auto Scaling User Guide.

Deletes the specified Auto Scaling group. If the group has instances or scaling activities in progress, you must specify the option to force the deletion in order for it to succeed. The force delete operation will also terminate the EC2 instances. If the group has a warm pool, the force delete option also deletes the warm pool. To remove instances from the Auto Scaling group before deleting it, call the DetachInstances API with the list of instances and the option to decrement the desired capacity. This ensures that Amazon EC2 Auto Scaling does not launch replacement instances. To terminate all instances before deleting the Auto Scaling group, call the UpdateAutoScalingGroup API and set the minimum size and desired capacity of the Auto Scaling group to zero. If the group has scaling policies, deleting the group deletes the policies, the underlying alarm actions, and any alarm that no longer has an associated action. For more information, see Delete your Auto Scaling infrastructure in the Amazon EC2 Auto Scaling User Guide.

Deletes the specified launch configuration. The launch configuration must not be attached to an Auto Scaling group. When this call completes, the launch configuration is no longer available for use.

Deletes the specified lifecycle hook. If there are any outstanding lifecycle actions, they are completed first (ABANDON for launching instances, CONTINUE for terminating instances).

Deletes the specified notification.

Deletes the specified scaling policy. Deleting either a step scaling policy or a simple scaling policy deletes the underlying alarm action, but does not delete the alarm, even if it no longer has an associated action. For more information, see Deleting a scaling policy in the Amazon EC2 Auto Scaling User Guide.

Deletes the specified scheduled action.

Deletes the specified tags.

Deletes the warm pool for the specified Auto Scaling group. For more information, see Warm pools for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide.

Describes the current Amazon EC2 Auto Scaling resource quotas for your account. When you establish an Amazon Web Services account, the account has initial quotas on the maximum number of Auto Scaling groups and launch configurations that you can create in a given Region. For more information, see Quotas for Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide.

Describes the available adjustment types for step scaling and simple scaling policies. The following adjustment types are supported: ChangeInCapacity ExactCapacity PercentChangeInCapacity

Gets information about the Auto Scaling groups in the account and Region. If you specify Auto Scaling group names, the output includes information for only the specified Auto Scaling groups. If you specify filters, the output includes information for only those Auto Scaling groups that meet the filter criteria. If you do not specify group names or filters, the output includes information for all Auto Scaling groups. This operation also returns information about instances in Auto Scaling groups. To retrieve information about the instances in a warm pool, you must call the DescribeWarmPool API.

Gets information about the Auto Scaling instances in the account and Region.

Describes the notification types that are supported by Amazon EC2 Auto Scaling.

Gets information about the instance refreshes for the specified Auto Scaling group. This operation is part of the instance refresh feature in Amazon EC2 Auto Scaling, which helps you update instances in your Auto Scaling group after you make configuration changes. To help you determine the status of an instance refresh, Amazon EC2 Auto Scaling returns information about the instance refreshes you previously initiated, including their status, start time, end time, the percentage of the instance refresh that is complete, and the number of instances remaining to update before the instance refresh is complete. If a rollback is initiated while an instance refresh is in progress, Amazon EC2 Auto Scaling also returns information about the rollback of the instance refresh.

Gets information about the launch configurations in the account and Region.

Describes the available types of lifecycle hooks. The following hook types are supported: autoscaling:EC2_INSTANCE_LAUNCHING autoscaling:EC2_INSTANCE_TERMINATING

Gets information about the lifecycle hooks for the specified Auto Scaling group.

This API operation is superseded by DescribeTrafficSources, which can describe multiple traffic sources types. We recommend using DetachTrafficSources to simplify how you manage traffic sources. However, we continue to support DescribeLoadBalancerTargetGroups. You can use both the original DescribeLoadBalancerTargetGroups API operation and DescribeTrafficSources on the same Auto Scaling group. Gets information about the Elastic Load Balancing target groups for the specified Auto Scaling group. To determine the attachment status of the target group, use the State element in the response. When you attach a target group to an Auto Scaling group, the initial State value is Adding. The state transitions to Added after all Auto Scaling instances are registered with the target group. If Elastic Load Balancing health checks are enabled for the Auto Scaling group, the state transitions to InService after at least one Auto Scaling instance passes the health check. When the target group is in the InService state, Amazon EC2 Auto Scaling can terminate and replace any instances that are reported as unhealthy. If no registered instances pass the health checks, the target group doesn't enter the InService state. Target groups also have an InService state if you attach them in the CreateAutoScalingGroup API call. If your target group state is InService, but it is not working properly, check the scaling activities by calling DescribeScalingActivities and take any corrective actions necessary. For help with failed health checks, see Troubleshooting Amazon EC2 Auto Scaling: Health checks in the Amazon EC2 Auto Scaling User Guide. 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. You can use this operation to describe target groups that were attached by using AttachLoadBalancerTargetGroups, but not for target groups that were attached by using AttachTrafficSources.

This API operation is superseded by DescribeTrafficSources, which can describe multiple traffic sources types. We recommend using DescribeTrafficSources to simplify how you manage traffic sources. However, we continue to support DescribeLoadBalancers. You can use both the original DescribeLoadBalancers API operation and DescribeTrafficSources on the same Auto Scaling group. Gets information about the load balancers for the specified Auto Scaling group. This operation describes only Classic Load Balancers. If you have Application Load Balancers, Network Load Balancers, or Gateway Load Balancers, use the DescribeLoadBalancerTargetGroups API instead. To determine the attachment status of the load balancer, use the State element in the response. When you attach a load balancer to an Auto Scaling group, the initial State value is Adding. The state transitions to Added after all Auto Scaling instances are registered with the load balancer. If Elastic Load Balancing health checks are enabled for the Auto Scaling group, the state transitions to InService after at least one Auto Scaling instance passes the health check. When the load balancer is in the InService state, Amazon EC2 Auto Scaling can terminate and replace any instances that are reported as unhealthy. If no registered instances pass the health checks, the load balancer doesn't enter the InService state. Load balancers also have an InService state if you attach them in the CreateAutoScalingGroup API call. If your load balancer state is InService, but it is not working properly, check the scaling activities by calling DescribeScalingActivities and take any corrective actions necessary. For help with failed health checks, see Troubleshooting Amazon EC2 Auto Scaling: Health checks in the Amazon EC2 Auto Scaling User Guide. 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.

Describes the available CloudWatch metrics for Amazon EC2 Auto Scaling.

Gets information about the Amazon SNS notifications that are configured for one or more Auto Scaling groups.

Gets information about the scaling policies in the account and Region.

Gets information about the scaling activities in the account and Region. When scaling events occur, you see a record of the scaling activity in the scaling activities. For more information, see Verifying a scaling activity for an Auto Scaling group in the Amazon EC2 Auto Scaling User Guide. If the scaling event succeeds, the value of the StatusCode element in the response is Successful. If an attempt to launch instances failed, the StatusCode value is Failed or Cancelled and the StatusMessage element in the response indicates the cause of the failure. For help interpreting the StatusMessage, see Troubleshooting Amazon EC2 Auto Scaling in the Amazon EC2 Auto Scaling User Guide.

Describes the scaling process types for use with the ResumeProcesses and SuspendProcesses APIs.