The difference between ELB Health Checks (at the TCP/HTTP level) and Auto Scaling Health Checks (EC2 status checks). If an EC2 instance is running but serving 500 errors, the ALB marks it unhealthy, but Auto Scaling won't replace it unless you configure it to honor ELB health. Domain 4: Monitoring, Logging, and Auditing (20%) You can't fix what you can't see. This domain pushes beyond basic dashboards into comprehensive observability .
This exam is notoriously difficult—not because the questions are tricky, but because it tests . It doesn’t ask, “What does CodeDeploy do?” It asks, “Your blue/green deployment is failing because the health check grace period conflicts with the Lambda warm-up time. How do you fix the auto-scaling policy to roll back automatically?” AWS Certified DevOps Engineer - Professional
If you hold the AWS Developer or SysOps Administrator Associate certifications, you might look at the AWS Certified DevOps Engineer – Professional (DOP-C02) and think, “I just need to know a few more CI/CD commands.” The difference between ELB Health Checks (at the