AZ-700 Question 197
Select 2You have an Azure Load Balancer configured to distribute incoming HTTPS traffic to a set of Azure virtual machines. You want to set up a health probe to ensure only healthy virtual machines receive traffic. The backend web application listens on HTTPS (port 443) and returns a 200 OK response on the /health endpoint. You plan to have the load balancer remove a virtual machine from rotation if it fails two consecutive health checks. Which two of the following configurations should you implement for your health probe?
- A
Configure a TCP-based probe on port 443 to check connectivity without specifying any URI path.
- B
Set the Interval property to 15 seconds and the UnhealthyThreshold property to 2.
- C
Use an HTTP-based probe on port 443 and specify /health as the request path.
- D
Leave the request path blank because the load balancer automatically checks root (/) for a 200 OK code.
Show answer and explanation
Correct answers: B, C
Explanation
In Azure Load Balancer, you must choose the appropriate probe protocol, port, and path to accurately track service availability. An HTTP(S) probe validates application health by checking for successful response codes (e.g., 200). A TCP probe only checks whether a port is open and does not validate HTTP statuses. For your scenario, configuring an HTTP-based probe for port 443 and using the /health path ensures paths are being served correctly. The Interval and UnhealthyThreshold settings manage how quickly and how many times a VM can fail before it is removed from the load balancer rotation. Refer to the Microsoft documentation on Azure Load Balancer health probes for additional details: https://learn.microsoft.com/azure/load-balancer/load-balancer-custom-probe-overview.
- A. Incorrect.
Incorrect. While a TCP-based probe can detect whether the port is open, it does not validate HTTP response codes or specific paths. Since your requirement is to check the /health endpoint and validate a 200 OK response, a TCP probe alone would not suffice for this scenario.
- B. Correct.
Correct. The Interval property determines how often the probe is sent, and the UnhealthyThreshold specifies how many consecutive failures will cause the virtual machine to be considered unhealthy. Setting Interval to 15 and UnhealthyThreshold to 2 matches your requirement to remove a VM from rotation after two failed attempts within 15-second intervals.
- C. Correct.
Correct. Because you are serving HTTPS traffic on port 443 and you specifically want to check the /health path for a 200 OK response, you must configure an HTTP probe targeting port 443 with the /health path. This ensures that the probe validates the application layer response.
- D. Incorrect.
Incorrect. When using an HTTP probe, leaving the path blank defaults to /. However, your scenario requires verifying the /health path for a 200 OK response. Failing to specify this path means the load balancer will check the root path, which may not reflect the health of the specific endpoint you intend to monitor.