Health Checks

5 minutes 5 Questions

Health checks are a feature of Route 53 that helps monitor the health and availability of resources by continuously sending automated requests to their endpoints. Route 53 can perform health checks on various types of endpoints, including web servers, mail servers, and other AWS resources. If a hea…

Guide: Amazon Route 53 - Health Checks

What is Amazon Route 53 Health Check?
Amazon Route 53 Health Check is a feature that checks and monitors the health of your resources such as web servers and email servers. If the health check status of a resource changes (i.e., if the condition specified in a health check evaluation fails), Amazon Route 53 initiates necessary actions such as rerouting traffic.

Why is it important?
It can help you achieve higher availability and improved load balancing by enabling Amazon Route 53 to reroute traffic away from unhealthy resources.

How it works?
Health Checks works by sending requests to the resource at a specified interval. If the resource does not respond in a timely manner, or the health check fails, Route 53 considers the resource 'unhealthy' and redirects network traffic.

Exam Tips: Answering Questions on Health Checks
It is essential to understand the different types of Health Checks (Basic and Advanced), and how they work. You should know how Failure Threshold (the number of times the health check must fail before the resource is marked 'unhealthy') affects the evaluation of resource health and how fast health changes are propagated through Route 53.

To tackle questions around Health Checks, remember to:
1) Familiarise with how health check works (i.e., know when AWS considers a resource 'healthy' or 'unhealthy').
2) Understand the role of health checks in DNS routing policies.
3) Know how to set up and configure a health check in Amazon Route 53.
Lastly, don't forget practice questions in this area as they often appear in the AWS Certified Solutions Architect - Associate exam.

Test mode:

Exam (Timed)

Practice (With explanations)

Start practice test

AWS Certified Solutions Architect - Health Checks Example Questions

Test your knowledge of Health Checks

Question 1

Your web application runs on an Auto Scaling group of EC2 instances behind an Application Load Balancer. You need Auto Scaling to automatically terminate and replace any instance that fails the ALB target group health checks. What should you configure to achieve this?

Configure the Auto Scaling group to use ELB (target group) health checks as its health check type so that instances failing the ALB target group health checks are terminated and replaced. Increase the desired capacity of Auto Scaling group Use an AWS Lambda function Decrease the cooldown period

Correct Answer: Configure the Auto Scaling group to use ELB (target group) health checks as its health check type so that instances failing the ALB target group health checks are terminated and replaced.

Application Load Balancer target groups perform health checks on registered instances. However, Auto Scaling will only terminate and replace instances based on those checks if the Auto Scaling group’s health check type is set to ELB (which, for ALBs, means using target group health status). When configured this way, the ASG monitors the ALB/target group health state; if an instance is marked unhealthy by the target group, the ASG marks it unhealthy, terminates it, and launches a replacement, honoring the health check grace period. Simply enabling target group health checks without configuring the ASG to use them will not cause automatic replacement. Increasing desired capacity, adjusting cooldown periods, or using a Lambda function do not directly ensure unhealthy instances are replaced by the ASG.

Question 2

You need an AWS service that automatically maintains application performance by dynamically scaling EC2 capacity and replacing unhealthy instances to keep the environment healthy. Which service should you use?

Amazon CloudWatch Logs AWS Trusted Advisor Amazon EC2 Auto Scaling AWS Config

Correct Answer: Amazon EC2 Auto Scaling

Amazon EC2 Auto Scaling automatically scales the number of EC2 instances based on demand and replaces unhealthy instances, helping maintain consistent performance and high availability. AWS Trusted Advisor provides recommendations but does not take action, Amazon CloudWatch Logs collects and stores logs without scaling or remediation, and AWS Config records configuration changes and compliance, not performance or health enforcement.

Question 3

Your application uses a Classic Load Balancer (CLB) in front of an Auto Scaling group. You need the load balancer to stop routing requests to any EC2 instance that fails a health check, but you do not want unhealthy instances to be terminated or replaced automatically. What should you do?

Enable and configure health checks in the Auto Scaling group Enable and configure health checks in the CLB Utilize a custom Amazon SNS topic for sending unhealthy instance notifications Replace the CLB with an Application Load Balancer (ALB)

Correct Answer: Enable and configure health checks in the CLB

Classic Load Balancer health checks determine whether an instance is considered InService or OutOfService. When a target fails the configured CLB health checks (e.g., HTTP 200 on a specific path, thresholds for healthy/unhealthy), the CLB immediately stops routing new requests to that instance without terminating it. Auto Scaling group health checks are for instance replacement and do not by themselves control whether the CLB sends traffic to an instance. An SNS topic only provides notifications and does not change routing behavior. Replacing the CLB with an ALB is unnecessary for this requirement.

🎓 Unlock Premium Access

AWS Certified Solutions Architect - Associate + ALL Certifications

🎓 Access to ALL Certifications: Study for any certification on our platform with one subscription
5645 Superior-grade AWS Certified Solutions Architect - Associate practice questions
Unlimited practice tests across all certifications
Detailed explanations for every question
AWS Certified Solutions Architect: 5 full exams plus all other certification exams
100% Satisfaction Guaranteed: Full refund if unsatisfied
Risk-Free: 7-day free trial with all premium features!

Start Your Free 7-Day Trial