aws_autoscaling: Option to permanently suspend processes

[aagmv]

Describe the feature

An option to create/configure an ASG to have processes always suspended.

Currently processes like such as AZRebalance can only be suspended during a CDK deployment, there's no option to mark a process as always suspended.

Use Case

AZRebalance interacts poorly with warm pools, during capacity shortages and with the long shutdown time of GPU instances.
Additionally our system frequently adjusts the desired capacity, having another process also mess with the running instances causes a disturbance that makes our control system back off.

So overall having this process running is just undesirable. Currently we suspend it manually after creating an ASG through the CDK, it would be nicer if the CDK could suspend it at creation time.

Proposed Solution

No response

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

AWS CDK Library version (aws-cdk-lib)

2.209.1

AWS CDK CLI version

2.1033.0

Environment details (OS name and version, etc.)

Debian 13

[pahud]

Thank you for this feature request. After investigating the CDK source code and CloudFormation documentation, I found that this feature cannot be implemented in CDK at this time because it requires upstream CloudFormation support. （Correct me if I was wrong)

Current Situation

The CDK's AutoScalingGroup construct only supports suspending processes temporarily during rolling updates via
the suspendProcesses property in RollingUpdateOptions.

However, the underlying issue is that CloudFormation's AWS::AutoScaling::AutoScalingGroup resource does not support a SuspendedProcesses property.

While the AWS Auto Scaling API provides SuspendProcesses and ResumeProcesses operations, these are runtime API calls, not declarative resource properties that CloudFormation can manage.

Next Steps

This feature requires CloudFormation to first add support for a SuspendedProcesses property on the AWS::AutoScaling::AutoScalingGroup resource. I'm adding the needs-cfn label to track this dependency.

Please consider opening a feature request in the CloudFormation coverage roadmap to request native support for permanently
suspended processes. I searched the roadmap and found no existing request for this specific capability (issue #300 only covers temporary suspension during updates).

[pahud]

Reference

AWS Documentation:

• Suspend and resume Amazon EC2 Auto Scaling processes - Main documentation page covering:
  • Types of processes (Launch, Terminate, HealthCheck, ReplaceUnhealthy, AZRebalance, AlarmNotification, ScheduledActions, AddToLoadBalancer, InstanceRefresh)
  • Considerations when suspending processes
  • How to suspend/resume processes via Console, CLI, or API
  • How suspended processes affect other processes

AWS CLI Documentation:

• suspend-processes - CLI command reference
• resume-processes - CLI command reference

AWS API Documentation:

• SuspendProcesses - API reference
• ResumeProcesses - API reference

Note: These are all runtime API operations - they don't cover declarative CloudFormation resource properties, which is what's missing and needed for this feature request.

[aagmv]

Created aws-cloudformation/cloudformation-coverage-roadmap#2429