IAmazonAutoScaling

When you attach instances, 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.

For more information, see Attach EC2 Instances to Your Auto Scaling Group in the Auto Scaling Developer Guide.

To describe the load balancers for an Auto Scaling group, use DescribeLoadBalancers. To detach the load balancer from the Auto Scaling group, use DetachLoadBalancers.

For more information, see Attach a Load Balancer to Your Auto Scaling Group in the Auto Scaling Developer Guide.

This step is a part of the procedure for adding a lifecycle hook to an Auto Scaling group:

1. (Optional) Create a Lambda function and a rule that allows CloudWatch Events to invoke your Lambda function when Auto Scaling launches or terminates instances.
2. (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 Auto Scaling to publish lifecycle notifications to the target.
3. Create the lifecycle hook. Specify whether the hook is used when the instances launch or terminate.
4. If you need more time, record the lifecycle action heartbeat to keep the instance in a pending state.
5. If you finish before the timeout period ends, complete the lifecycle action.

For more information, see Auto Scaling Lifecycle in the Auto Scaling Developer Guide.

If you exceed your maximum limit of Auto Scaling groups, which by default is 20 per region, the call fails. For information about viewing and updating this limit, see DescribeAccountLimits.

For more information, see Auto Scaling Groups in the Auto Scaling Developer Guide.

If you exceed your maximum limit of launch configurations, which by default is 100 per region, the call fails. For information about viewing and updating this limit, see DescribeAccountLimits.

For more information, see Launch Configurations in the Auto Scaling Developer Guide.

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 Tagging Auto Scaling Groups and Instances in the Auto Scaling Developer Guide.

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.

If the group has policies, deleting the group deletes the policies, the underlying alarm actions, and any alarm that no longer has an associated action.

To remove instances from the Auto Scaling group before deleting it, call DetachInstances with the list of instances and the option to decrement the desired capacity so that Auto Scaling does not launch replacement instances.

To terminate all instances before deleting the Auto Scaling group, call UpdateAutoScalingGroup and set the minimum size and desired capacity of the Auto Scaling group to zero.

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.

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

Deleting a policy deletes the underlying alarm action, but does not delete the alarm, even if it no longer has an associated action.

For information about requesting an increase in these limits, see AWS Service Limits in the Amazon Web Services General Reference.

For information about requesting an increase in these limits, see AWS Service Limits in the Amazon Web Services General Reference.

Note that the GroupStandbyInstances metric is not returned by default. You must explicitly request this metric when calling EnableMetricsCollection.

Note that the GroupStandbyInstances metric is not returned by default. You must explicitly request this metric when calling EnableMetricsCollection.

You can use filters to limit the results. For example, you can query for the tags for a specific Auto Scaling group. You can specify multiple values for a filter. A tag must match at least one of the specified values for it to be included in the results.

You can also specify multiple filters. The result includes information for a particular tag only if it matches all the filters. If there's no match, no special message is returned.

You can use filters to limit the results. For example, you can query for the tags for a specific Auto Scaling group. You can specify multiple values for a filter. A tag must match at least one of the specified values for it to be included in the results.

You can also specify multiple filters. The result includes information for a particular tag only if it matches all the filters. If there's no match, no special message is returned.

After the instances are detached, you can manage them independently from the rest of the Auto Scaling group.

If you do not specify the option to decrement the desired capacity, Auto Scaling launches instances to replace the ones that are detached.

For more information, see Detach EC2 Instances from Your Auto Scaling Group in the Auto Scaling Developer Guide.

When you detach a load balancer, it enters the Removing state while deregistering the instances in the group. When all instances are deregistered, then you can no longer describe the load balancer using DescribeLoadBalancers. Note that the instances remain running.

You can only enable metrics collection if InstanceMonitoring in the launch configuration for the group is set to True.

For more information, see Auto Scaling Lifecycle in the Auto Scaling Developer Guide.

For more information, see Auto Scaling Lifecycle in the Auto Scaling Developer Guide.

A lifecycle hook tells Auto Scaling that you want to perform an action on an instance that is not actively in service; for example, either when the instance launches or before the instance terminates.

This step is a part of the procedure for adding a lifecycle hook to an Auto Scaling group:

1. (Optional) Create a Lambda function and a rule that allows CloudWatch Events to invoke your Lambda function when Auto Scaling launches or terminates instances.
2. (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 Auto Scaling to publish lifecycle notifications to the target.
3. Create the lifecycle hook. Specify whether the hook is used when the instances launch or terminate.
4. If you need more time, record the lifecycle action heartbeat to keep the instance in a pending state.
5. If you finish before the timeout period ends, complete the lifecycle action.

For more information, see Auto Scaling Lifecycle in the Auto Scaling Developer Guide.

If you exceed your maximum limit of lifecycle hooks, which by default is 50 per region, the call fails. For information about updating this limit, see AWS Service Limits in the Amazon Web Services General Reference.

For more information see Getting Notifications When Your Auto Scaling Group Changes in the Auto Scaling Developer Guide.

This configuration overwrites an existing configuration.

If you exceed your maximum limit of step adjustments, which by default is 20 per region, the call fails. For information about updating this limit, see AWS Service Limits in the Amazon Web Services General Reference.

For more information, see Scheduled Scaling in the Auto Scaling Developer Guide.

This step is a part of the procedure for adding a lifecycle hook to an Auto Scaling group:

1. (Optional) Create a Lambda function and a rule that allows CloudWatch Events to invoke your Lambda function when Auto Scaling launches or terminates instances.
2. (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 Auto Scaling to publish lifecycle notifications to the target.
3. Create the lifecycle hook. Specify whether the hook is used when the instances launch or terminate.
4. If you need more time, record the lifecycle action heartbeat to keep the instance in a pending state.
5. If you finish before the timeout period ends, complete the lifecycle action.

For more information, see Auto Scaling Lifecycle in the Auto Scaling Developer Guide.

For more information, see Suspending and Resuming Auto Scaling Processes in the Auto Scaling Developer Guide.

For more information about desired capacity, see What Is Auto Scaling? in the Auto Scaling Developer Guide.

For more information, see Health Checks in the Auto Scaling Developer Guide.

For more information, see Instance Protection in the Auto Scaling Developer Guide.

Note that if you suspend either the Launch or Terminate process types, it can prevent other process types from functioning properly.

To resume processes that have been suspended, use ResumeProcesses.

For more information, see Suspending and Resuming Auto Scaling Processes in the Auto Scaling Developer Guide.

This call simply makes a termination request. The instance is not terminated immediately.

To update an Auto Scaling group with a launch configuration with InstanceMonitoring set to False, you must first disable the collection of group metrics. Otherwise, you will get an error. If you have previously enabled the collection of group metrics, you can disable it using DisableMetricsCollection.

The new settings are registered upon the completion of this call. Any launch configuration settings take effect on any triggers after this call returns. Scaling activities that are currently in progress aren't affected.

Note the following:

• 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, we implicitly call SetDesiredCapacity to set the size of the group to the new value of MinSize.

• 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, we implicitly call SetDesiredCapacity to set the size of the group to the new value of MaxSize.

• All other optional parameters are left unchanged if not specified.