Update an Amazon EC2 Auto Scaling group
You can update most of your Amazon EC2 Auto Scaling group's details. You can't update the name of an Amazon EC2 Auto Scaling group or change its AWS Region.
To update an Amazon EC2 Auto Scaling group (console)
Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/
, and choose Amazon EC2 Auto Scaling Groups from the navigation pane. -
Choose your Amazon EC2 Auto Scaling group to display information about the group, with tabs for Details, Activity, Automatic scaling, Instance management, Monitoring, and Instance refresh.
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Choose the tabs for the configuration areas that you're interested in and update the settings as needed. For each setting that you edit, choose Update to save your changes to the Amazon EC2 Auto Scaling group's configuration.
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Details tab
These are the general settings for your Amazon EC2 Auto Scaling group. You can edit and manage these in the same way as during Amazon EC2 Auto Scaling group creation.
The Advanced configurations section has some options that are not available when creating the group such as termination policies, cooldown, suspended processes, and maximum instance lifetime. You can also view, but not edit the placement group and service-linked role of the Amazon EC2 Auto Scaling group.
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Integrations tab
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Load balancing – ELB
If the group is associated with ELB resources, see Add an Availability Zone before changing Availability Zones. Some restrictions on the load balancer might prevent you from applying changes to your group's Availability Zones to your load balancer's Availability Zones.
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VPC Lattice integration options – VPC Lattice
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ARC zonal shift – Amazon EC2 Auto Scaling group zonal shift
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Automatic scaling tab
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Dynamic scaling policies – Dynamic scaling policies
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Predictive scaling policies – Predictive scaling policies
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Scheduled actions – Scheduled actions
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Instance management tab
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Lifecycle hooks – Lifecycle hooks
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Warm pool – Warm pools
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Activity tab
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Activity notifications – Amazon SNS notifications
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Monitoring tab
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There is just a single option in this tab, which lets you enable or disable CloudWatch group metrics collection.
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To update an Amazon EC2 Auto Scaling group using the command line
You can use one of the following commands:
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update-auto-scaling-group
(AWS CLI) -
Update-ASAutoScalingGroup (AWS Tools for Windows PowerShell)
Update Amazon EC2 Auto Scaling instances
If you associate a new launch template or launch configuration with an Amazon EC2 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. To apply your changes to existing instances, you have the following options:
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Start an instance refresh to replace the older instances. For more information, see Use an instance refresh to update instances in an Amazon EC2 Auto Scaling group.
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Wait for scaling activities to gradually replace older instances with newer instances based on your termination policies.
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Manually terminate them so that they are replaced by your Amazon EC2 Auto Scaling group.
Note
You can change the following instance attributes by specifying them as part of the launch template or launch configuration:
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Amazon Machine Image (AMI)
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block devices
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key pair
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instance type
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security groups
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user data
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monitoring
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IAM instance profile
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placement tenancy
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kernel
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ramdisk
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whether the instance has a public IP address
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the Availability Zone distribution strategy
Amazon EC2 Auto Scaling group allocation strategy and capacity changes
When you change an Amazon EC2 Auto Scaling group allocation strategy, existing instances are
not replaced. Any new instances that are launched because of scale out events will
follow the new allocation strategy. Any future scale in events will follow the
termination policy and
use the new allocation strategy if the termination policy is set to Default or AllocationStrategy.
For example, if you change the allocation strategy from lowest-price to price-capacity-optimized, there might
not be any instance terminations, but any new instances will be launched with the
new allocation strategy. Instance type changes do not affect existing instances.
When you change certain parameters such as the OnDemandBaseCapacity or the
OnDemandPercentageAboveBaseCapacity, Amazon EC2 Auto Scaling will automatically rebalance if the percentage of On-Demand Instances
and Spot Instances do not match the new specifications. For example, suppose an Amazon EC2 Auto Scaling group has the OnDemandPercentageAboveBaseCapacity set to 50 percent On-Demand Instances and 50 percent Spot Instances. Then, the OnDemandPercentageAboveBaseCapacity
is increased to 100 percent On-Demand Instances. The Amazon EC2 Auto Scaling group will proactively rebalance by launching new On-Demand Instances and terminating Spot Instances.
The instance maintenance policy that you defined determines the order of the launch and termination activities.
