# Ensure Auto Scaling Groups Use ELB Health Checks

- Source: https://support.icompaas.com/support/solutions/articles/62000233478-ensure-auto-scaling-groups-use-elb-health-checks
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [AWS Checks New Version](https://support.icompaas.com/support/solutions/62000112673) › [AWS New Checks](https://support.icompaas.com/support/solutions/folders/62000169206)
- Last updated: 2026-05-29
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**Profile Applicability** 

-   **Level 2**

#### **Description**

Elastic Load Balancing (ELB) health checks allow Auto Scaling groups to monitor the health of instances based on the status reported by the load balancer. By enabling ELB health checks, Auto Scaling can replace unhealthy instances, ensuring high availability and optimal performance for your applications.

#### **Rationale**

-   Improved Fault Tolerance: Automatically replaces unhealthy instances based on ELB health checks.
    
-   Enhanced Availability: Ensures that only healthy instances serve traffic.
    
-   Compliance: Aligns with best practices for resilient and highly available architectures.
    

#### **Impact**

**Pros:**

-   Ensures that traffic is routed only to healthy instances.
    
-   Improves application reliability and user experience.
    
-   Automates the replacement of unhealthy instances.
    

**Cons:**

-   Requires proper configuration of ELB health checks.
    
-   May cause temporary disruptions if health checks are misconfigured.
    

#### **Default Value**

By default, Auto Scaling groups use EC2 instance status checks for health monitoring. ELB health checks must be explicitly enabled.

#### **Pre-Requisite**

IAM Permissions Required:

-   autoscaling:DescribeAutoScalingGroups
    
-   autoscaling:UpdateAutoScalingGroup
    
-   AWS CLI installed and configured.
    

#### **Remediation**

#### **Test Plan:**

**Using AWS Console:**

1.  Sign in to the AWS Management Console.
    
2.  Navigate to EC2 > Auto Scaling Groups.
    
3.  Select the Auto Scaling Group associated with a load balancer.
    
4.  Under the Details tab, check the Health Check Type field. Verify that it includes ELB.
    

**Using AWS CLI:**

1.  Describe the Auto Scaling Group:  
    
    aws autoscaling describe-auto-scaling-groups --auto-scaling-group-names <asg-name>
    
2.  Check the HealthCheckType field in the output. Ensure it is set to ELB.
    

#### **Implementation Steps:**

**Using AWS Console:**

1.  Navigate to EC2 > Auto Scaling Groups.![](https://support.icompaas.com/assets/kb/d97198a6fc825f7f.png)![](https://support.icompaas.com/assets/kb/3e4a7d1bbc668ac3.png) 
    
2.  Select the Auto Scaling Group to update.
    
3.  Click Edit and update the Health Check Type to ELB.![](https://support.icompaas.com/assets/kb/2a9624476bbabe7d.png)![](https://support.icompaas.com/assets/kb/fb0c5361955f06c2.png)![](https://support.icompaas.com/assets/kb/f025e47c18508bab.png)
    
4.  Set the Health Check Grace Period to allow sufficient time for instances to initialize before health checks begin.
    
5.  Save the updated configuration.
    

**Using AWS CLI:**

1.  Enable ELB health checks for the Auto Scaling Group:  
    
    aws autoscaling update-auto-scaling-group \\
    --auto-scaling-group-name <asg-name> \\
    --health-check-type ELB \\
    --health-check-grace-period <grace-period-in-seconds>
    

2.  Verify the updated configuration:  
    
    aws autoscaling describe-auto-scaling-groups --auto-scaling-group-names <asg-name>
    

#### **Backout Plan**

#### **Using AWS Console:**

1.  #### If enabling ELB health checks causes issues, sign in to the AWS Management Console.
    
2.  #### Navigate to EC2, then to Auto Scaling Groups.![](https://support.icompaas.com/assets/kb/0f5cc6b3ca4ace7f.png)![](https://support.icompaas.com/assets/kb/efa36ca09959b6e4.png)
    
3.  #### Select the Auto Scaling Group and go to the Health Checks section.![](https://support.icompaas.com/assets/kb/03dd41397589f78c.png)
    
4.  #### Change the Health Check Type from ELB back to EC2 if necessary.![](https://support.icompaas.com/assets/kb/f3016215eacac4d0.png)![](https://support.icompaas.com/assets/kb/ad67f6ace90f8a39.png)
    
5.  #### Save the changes and verify that EC2 health checks are now in use.
    

#### **Using AWS CLI:**

1.  #### To revert back to EC2 health checks, run:  
    
    aws autoscaling update-auto-scaling-group --auto-scaling-group-name <ASG\_NAME> --health-check-type EC2 --health-check-grace-period <GRACE\_PERIOD>
    
2.  #### Verify that the EC2 health checks are now in use:  
    
    aws autoscaling describe-auto-scaling-groups --auto-scaling-group-name <ASG\_NAME>
    

#### **References**

-   [Health Checks for Auto Scaling Groups](https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-health-checks.html)
    
-   [Attaching Load Balancers to Auto Scaling Groups](https://docs.aws.amazon.com/autoscaling/ec2/userguide/attach-load-balancer-asg.html)
    
-   [Best Practices for ELB Health Checks](https://docs.aws.amazon.com/autoscaling/ec2/userguide/health-checks-overview.html)

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.