Auto Scaling groups with a load balancer should use health checks
This rule ensures auto-scaling groups with a load balancer utilize health checks for optimal performance.
| Rule | Auto Scaling groups with a load balancer should use health checks |
| Framework | NIST Cybersecurity Framework (CSF) v1.1 |
| Severity | ✔ Critical |
Auto Scaling groups with Load Balancer Health Checks for NIST Cybersecurity Framework (CSF) v1
The National Institute of Standards and Technology (NIST) Cybersecurity Framework provides guidelines for organizations to manage and mitigate cybersecurity risks. Auto Scaling groups in cloud environments like AWS can be configured to work with Elastic Load Balancers (ELB) to ensure high availability and fault tolerance for applications. Integrating health checks improves resilience and aligns with the NIST CSF best practices.
Understanding Health Checks in Auto Scaling with Load Balancers
Description
Auto Scaling ensures that your application has the right amount of compute capacity to handle the load of your application efficiently. A Load Balancer distributes incoming application traffic across multiple instances to maximize responsiveness. Health checks are crucial for monitoring the state of the instances within the Auto Scaling group. If an instance fails to meet the health criteria, it can be automatically replaced, ensuring that your application remains operational.
Implementation
- 1.Configure Load Balancer Health Checks: A Load Balancer performs health checks on all registered instances at specified intervals.
- 2.Enable ELB Health Checks in the Auto Scaling Group: This tells the Auto Scaling group to consider the health status provided by the load balancer when evaluating the health state of each instance.
Step by Step Guide for Remediation and Necessary CLI Commands
Step 1: Enable Health Checks on the Load Balancer
Enable health checks on your load balancer by specifying the target (e.g., HTTP endpoint) and the interval.
AWS CLI Command:
aws elb configure-health-check --load-balancer-name my-load-balancer-name --health-check Target=HTTP:80/index.html,Interval=30,UnhealthyThreshold=2,HealthyThreshold=2,Timeout=3
Step 2: Configure the Auto Scaling Group to Use Load Balancer Health Checks
By default, Auto Scaling groups only use EC2 health checks. Modify the Auto Scaling group to include ELB health checks:
AWS CLI Command:
aws autoscaling update-auto-scaling-group --auto-scaling-group-name my-auto-scaling-group --health-check-type ELB --health-check-grace-period 300
This command updates the specified Auto Scaling group to use ELB health checks with a grace period of 300 seconds before considering an instance unhealthy.
Troubleshooting Steps
- Check if Load Balancer health checks are correctly configured: Confirm that the specified target for HTTP/HTTPS checks delineates a valid path and that the target instance has the necessary rules in its security group.
- Ensure proper security group configuration: The security group attached to the instances must allow traffic from the Load Balancer.
- Verify the health check grace period: The grace period should be sufficient for an instance to boot up and start the application.
Remediation
If any issues are identified during troubleshooting:
- Reconfigure the health check parameters: Adjust health check settings as needed—targets, thresholds, intervals, etc.
- Update security group rules: If necessary, modify your instance security group rules to ensure the Load Balancer can communicate with the instances.
- Modify the health check grace period: If instances are being marked unhealthy too quickly due to startup times, increase the grace period.
Conclusion
Following these guidelines helps ensure that your Auto Scaling groups with Load Balancers are aligned with the NIST Cybersecurity Framework, enhancing the security and resilience of your cloud infrastructure. By implementing and maintaining proper health checks, you can achieve a more robust and reliable deployment, which is a fundamental goal of the NIST CSF.