Target Groups

Target groups perform health checks to determine if targets are healthy and ready to receive traffic. The health check configuration includes:

• Health check path: The endpoint to check (e.g., / or /health)
• Health check interval: How often to check (e.g., every 30 seconds)
• Health check timeout: How long to wait for a response (e.g., 5 seconds)
• Healthy threshold: How many consecutive successful checks before marking as healthy (e.g., 2)
• Unhealthy threshold: How many consecutive failed checks before marking as unhealthy (e.g., 2)

If a target fails its health checks, the load balancer stops sending traffic to it. Once it passes health checks again, traffic resumes automatically.

Create a target group named patientping-tg and update the load balancer listener to forward traffic to it instead of the static response.

1. Create the target group from the console:
   1. In the AWS Console, navigate to EC2, then open Target Groups under Load Balancing.
   2. Click Create target group.
   3. For Target type, select IP addresses.
   4. Set Target group name to patientping-tg.
   5. For Protocol and Port, use HTTP and 8000 (the port your container listens on).
   6. Select your patientping VPC.
   7. Under Health checks, keep the Path as / and leave the other defaults (interval, timeout, thresholds) as-is, or mirror the values shown in the lesson if you want to practice tuning them.
   8. Click Next, then Create target group. We won't register targets yet.
2. Update the existing listener on patientping-alb to forward to this target group:
   1. In the AWS Console, navigate to EC2 → Load Balancers, and select patientping-alb.
   2. Go to the Listeners tab and click on the HTTP (port 80) listener.
   3. Click Edit (or View/edit rules) and change the Default action from Return fixed response to Forward to target groups.
   4. Choose the patientping-tg target group you just created.
   5. Save the changes.

Run and submit the tests to verify your target group is configured correctly.