Suspending Amazon EC2 Auto Scaling processes during deployments

Amazon EC2 Auto Scaling can remove or replace instances during an in-place deployment, including instances that CodeDeploy is updating. For example, a scale-in event can terminate an instance in the middle of its update, or rebalancing can move instances between Availability Zones. To prevent this, you can choose Amazon EC2 Auto Scaling processes for CodeDeploy to suspend while the deployment runs. CodeDeploy suspends these processes before it deploys to instances in your Auto Scaling groups. It resumes them when the deployment succeeds, fails, or is stopped.

When you can suspend processes

You can suspend processes for deployments that meet all of the following conditions:

CodeDeploy doesn't suspend processes for blue/green deployments. If you choose processes for a deployment group that doesn't meet these conditions, CodeDeploy rejects the request.

CodeDeploy suspends processes only on the Auto Scaling groups in the deployment group. It doesn't affect instances that you add to the deployment group by tags, or on-premises instances.

Processes you can suspend

You can suspend the following processes, in any combination:

CodeDeploy allows only these processes because leaving them suspended has a limited impact, which is mostly extra cost. Other processes, such as Launch, HealthCheck, and ReplaceUnhealthy, keep the Auto Scaling group healthy and able to add capacity, so CodeDeploy doesn't suspend them.

If an Auto Scaling group already has a process suspended when the deployment starts, CodeDeploy doesn't resume that process after the deployment.

For more information about how suspending a process affects your Auto Scaling group, see Understand how suspending processes affects other processes in the Amazon EC2 Auto Scaling User Guide.

Required permissions for suspending Auto Scaling processes

The service role for the deployment group must allow the following actions on the Auto Scaling groups in the deployment group:

If the service role uses the AWSCodeDeployRole managed policy, it already has these permissions. If you use a custom service role, add these actions to it. For instructions on creating a service role, see Step 2: Create a service role for CodeDeploy.

If the service role is missing these permissions, CodeDeploy doesn't create the deployment, and the error names the missing IAM actions.

Considerations for suspending Auto Scaling processes

Keep the following in mind when you suspend processes:

Suspending processes for a deployment group (console)

You can choose the processes when you create or edit a deployment group. Every deployment to the group uses this setting unless the deployment overrides it.

The deployment group details page shows the processes under Processes to suspend, in the Auto Scaling groups section.

Overriding the setting for a single deployment (console)

A deployment can suspend a different set of processes than its deployment group, or none.

The deployment details page shows the processes under Suspended Auto Scaling processes.

Suspending processes (AWS CLI)

Use the ec2DeploymentOptions parameter. For more information, see EC2DeploymentOptions in the AWS CodeDeploy API Reference. Process names are case sensitive.

The examples are formatted for Linux, macOS, or Unix.

To set the processes on a deployment group, use the create-deployment-group or update-deployment-group command with the --ec2-deployment-options option. In the following examples, replace my-application and my-deployment-group with your application and deployment group names. The following AWS CLI command suspends Terminate and AZRebalance for every deployment in the deployment group:

aws deploy update-deployment-group \
    --application-name my-application \
    --current-deployment-group-name my-deployment-group \
    --ec2-deployment-options '{"autoScalingGroupProcessesToSuspend":["Terminate","AZRebalance"]}'

The following AWS CLI command stops suspending processes for the deployment group:

aws deploy update-deployment-group \
    --application-name my-application \
    --current-deployment-group-name my-deployment-group \
    --ec2-deployment-options '{"autoScalingGroupProcessesToSuspend":[]}'

To override the setting for a single deployment, use the create-deployment command with the --ec2-deployment-options option. If you don't specify the option, the deployment uses the deployment group setting. If you specify an empty list, the deployment doesn't suspend any processes. The following AWS CLI command suspends only Terminate for this deployment:

aws deploy create-deployment \
    --application-name my-application \
    --deployment-group-name my-deployment-group \
    --s3-location bucket=amzn-s3-demo-bucket,key=my-app.zip,bundleType=zip \
    --ec2-deployment-options '{"autoScalingGroupProcessesToSuspend":["Terminate"]}'

Resuming processes manually (AWS CLI)

Use the following AWS CLI command to list the suspended processes on an Auto Scaling group:

aws autoscaling describe-auto-scaling-groups \
    --auto-scaling-group-names my-asg \
    --query 'AutoScalingGroups[0].SuspendedProcesses'

If successful, the command returns output similar to the following:

[
    {
        "ProcessName": "Terminate",
        "SuspensionReason": "User suspended at 2026-10-27T10:15:42Z"
    },
    {
        "ProcessName": "AZRebalance",
        "SuspensionReason": "User suspended at 2026-10-27T10:15:42Z"
    }
]

Use the following AWS CLI command to resume the processes:

aws autoscaling resume-processes \
    --auto-scaling-group-name my-asg \
    --scaling-processes Terminate AZRebalance

You can also resume processes in the Amazon EC2 console. For more information, see Resume processes in the Amazon EC2 Auto Scaling User Guide.