Event Information

  • The PutScalingPolicy event in AWS Auto Scaling refers to the action of creating or updating a scaling policy for an Auto Scaling group.
  • This event is triggered when a user or an application programmatically creates or modifies a scaling policy using the AWS Auto Scaling API or AWS Management Console.
  • The PutScalingPolicy event allows you to define the scaling behavior for your Auto Scaling group, such as increasing or decreasing the number of instances based on certain conditions or metrics.

Examples

  • Unauthorized access: If proper access controls are not in place, an attacker could potentially gain unauthorized access to the PutScalingPolicy API and create or modify scaling policies without proper authorization. This could lead to unintended scaling actions or resource exhaustion.

  • Insecure policy configurations: If the scaling policies are not properly configured, it could result in unintended or excessive scaling actions. For example, if a scaling policy is set to scale up or down too aggressively, it could lead to unnecessary resource allocation or depletion.

  • Lack of monitoring and auditing: Without proper monitoring and auditing of scaling policies, it becomes difficult to detect and respond to any unauthorized or malicious changes. This can result in delayed detection of security incidents or policy violations, increasing the risk of security breaches.

Remediation

Using Console

  1. Identify the issue: Use the AWS console to monitor the Auto Scaling group and identify any scaling issues or anomalies. Look for instances that are consistently failing health checks or instances that are not being replaced when they become unhealthy.

  2. Adjust Auto Scaling group settings: Access the AWS console and navigate to the Auto Scaling group that is experiencing the issue. Modify the desired capacity, minimum size, or maximum size of the group to ensure that it can scale up or down as needed. This can be done by selecting the Auto Scaling group, clicking on the “Edit” button, and adjusting the appropriate settings.

  3. Configure health checks: Configure health checks for the Auto Scaling group to ensure that instances are replaced when they become unhealthy. In the AWS console, go to the Auto Scaling group, select the “Health check type” option, and choose the appropriate health check type (e.g., EC2 or ELB). Configure the health check grace period and threshold as per your requirements.

  4. Monitor and test: After making the necessary adjustments, monitor the Auto Scaling group to ensure that instances are scaling up or down as expected. Test the health check configuration by intentionally causing an instance to become unhealthy and verifying that it is replaced by a new instance.

  5. Review and optimize: Regularly review the Auto Scaling group settings and health check configurations to ensure they are still appropriate for your application’s needs. Optimize the scaling policies and thresholds based on the observed behavior and performance of your application.

Note: The steps provided are general guidelines and may vary depending on the specific requirements and configurations of your AWS Auto Scaling group. It is recommended to refer to the AWS documentation for detailed instructions and best practices.

Using CLI

  1. To remediate an issue with AWS AutoScaling using AWS CLI, you can use the following CLI commands:
  • To update the desired capacity of an Auto Scaling group:
aws autoscaling update-auto-scaling-group --auto-scaling-group-name <auto-scaling-group-name> --desired-capacity <desired-capacity>

Replace <auto-scaling-group-name> with the name of your Auto Scaling group and <desired-capacity> with the desired number of instances.

  • To update the minimum and maximum size of an Auto Scaling group:
aws autoscaling update-auto-scaling-group --auto-scaling-group-name <auto-scaling-group-name> --min-size <min-size> --max-size <max-size>

Replace <auto-scaling-group-name> with the name of your Auto Scaling group, <min-size> with the minimum number of instances, and <max-size> with the maximum number of instances.

  • To update the launch configuration of an Auto Scaling group:
aws autoscaling update-auto-scaling-group --auto-scaling-group-name <auto-scaling-group-name> --launch-configuration-name <launch-configuration-name>

Replace <auto-scaling-group-name> with the name of your Auto Scaling group and <launch-configuration-name> with the name of the updated launch configuration.

  1. To remediate an issue with AWS AutoScaling using AWS CLI, you can use the following CLI commands:
  • To suspend scaling processes for an Auto Scaling group:
aws autoscaling suspend-processes --auto-scaling-group-name <auto-scaling-group-name> --scaling-processes <scaling-processes>

Replace <auto-scaling-group-name> with the name of your Auto Scaling group and <scaling-processes> with a comma-separated list of scaling processes to suspend.

  • To resume scaling processes for an Auto Scaling group:
aws autoscaling resume-processes --auto-scaling-group-name <auto-scaling-group-name> --scaling-processes <scaling-processes>

Replace <auto-scaling-group-name> with the name of your Auto Scaling group and <scaling-processes> with a comma-separated list of scaling processes to resume.

  • To set a specific instance protection state for instances in an Auto Scaling group:
aws autoscaling set-instance-protection --instance-ids <instance-ids> --auto-scaling-group-name <auto-scaling-group-name> --protected-from-scale-in <true|false>

Replace <instance-ids> with a comma-separated list of instance IDs, <auto-scaling-group-name> with the name of your Auto Scaling group, and <true|false> with either true or false to enable or disable instance protection.

  1. To remediate an issue with AWS AutoScaling using AWS CLI, you can use the following CLI commands:
  • To create a new launch configuration:
aws autoscaling create-launch-configuration --launch-configuration-name <launch-configuration-name> --image-id <image-id> --instance-type <instance-type> --security-groups <security-groups> --key-name <key-name>

Replace <launch-configuration-name> with the name of the new launch configuration, <image-id> with the ID of the desired Amazon Machine Image (AMI), <instance-type> with the desired instance type, <security-groups> with a comma-separated list of security group IDs, and <key-name> with the name of the key pair.

  • To delete an existing launch configuration:
aws autoscaling delete-launch-configuration --launch-configuration-name <launch-configuration-name>

Replace <launch-configuration-name> with the name of the launch configuration to delete.

  • To update the instance protection settings for instances in an Auto Scaling group:
aws autoscaling set-instance-protection --instance-ids <instance-ids> --auto-scaling-group-name <auto-scaling-group-name> --protected-from-scale-in <true|false>

Replace <instance-ids> with a comma-separated list of instance IDs, <auto-scaling-group-name> with the name of your Auto Scaling group, and <true|false> with either true or false to enable or disable instance protection.

Using Python

To remediate AWS AutoScaling issues using Python, you can use the following approaches:

  1. Adjusting Auto Scaling Group (ASG) Parameters:

    • Use the AWS SDK for Python (Boto3) to modify the desired capacity, minimum and maximum size of the ASG based on the specific requirements.
    • Example script:
      import boto3
      
      def adjust_asg_capacity(asg_name, min_size, max_size, desired_capacity):
          autoscaling_client = boto3.client('autoscaling')
          response = autoscaling_client.update_auto_scaling_group(
              AutoScalingGroupName=asg_name,
              MinSize=min_size,
              MaxSize=max_size,
              DesiredCapacity=desired_capacity
          )
          print(response)
      
      adjust_asg_capacity('my-asg', 2, 10, 5)
      
  2. Modifying Launch Configuration:

    • Use Boto3 to update the launch configuration associated with the ASG to change instance types, security groups, or any other required configurations.
    • Example script:
      import boto3
      
      def modify_launch_configuration(lc_name, instance_type, security_groups):
          autoscaling_client = boto3.client('autoscaling')
          response = autoscaling_client.update_launch_configuration(
              LaunchConfigurationName=lc_name,
              InstanceType=instance_type,
              SecurityGroups=security_groups
          )
          print(response)
      
      modify_launch_configuration('my-lc', 't2.micro', ['sg-12345678'])
      
  3. Implementing Custom Scaling Policies:

    • Use Boto3 to create custom scaling policies that define specific scaling actions based on CloudWatch alarms or other metrics.
    • Example script:
      import boto3
      
      def create_scaling_policy(asg_name, policy_name, adjustment_type, scaling_adjustment, cooldown):
          autoscaling_client = boto3.client('autoscaling')
          response = autoscaling_client.put_scaling_policy(
              AutoScalingGroupName=asg_name,
              PolicyName=policy_name,
              AdjustmentType=adjustment_type,
              ScalingAdjustment=scaling_adjustment,
              Cooldown=cooldown
          )
          print(response)
      
      create_scaling_policy('my-asg', 'my-policy', 'ChangeInCapacity', 2, 300)
      

Please note that the provided scripts are just examples and may need to be customized based on your specific requirements and environment.