Microsoft Certified: Azure Administrator AssociateDeploy and manage Azure compute resourcesMedium
A company hosts a critical web application on multiple Azure virtual machines (VMs) behind an Azure Standard Load Balancer. The application experiences intermittent performance degradation, and you suspect that some backend VMs are becoming unhealthy. You need to configure a health probe to automatically remove unhealthy VMs from the load balancer rotation.
- AConfigure an HTTP health probe on port 80 targeting the root path '/'.
- BConfigure a TCP health probe on port 3389 to check RDP connectivity.
- CConfigure an ICMP health probe to check basic network connectivity.
- DConfigure a custom UDP health probe on a high port number.
Show answer & explanationAnswer & explanation
Correct answer: A. Configure an HTTP health probe on port 80 targeting the root path '/'.
For a web application, an HTTP health probe on the application's port (like 80 or 443) that targets a specific path (e.g., '/') is the most effective way to determine if the application itself is responsive and healthy, not just if the VM is up.
Why the other options are wrong
- B. RDP (port 3389) checks VM remote access, not web application health.
- C. ICMP only checks basic network reachability, not the health of the application running on the VM.
- D. UDP probes are less common for web applications and don't provide the same level of application-layer health check as HTTP.
Azure Load Balancer Health Probes
Mechanisms used by Azure Load Balancer to determine the health of backend instances. If a probe fails, the instance is taken out of rotation until it passes the probe again.
- Supports TCP, HTTP, and HTTPS protocols.
- HTTP/HTTPS probes are best for application health checks.
- TCP probes check if a port is listening.
- Configured with interval and unhealthy threshold.
Memory trick: Probes Check App's Life.