Backend pools and health probes in Azure - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a backend pool in Azure Load Balancer?

A backend pool is a group of virtual machines or instances that receive traffic from the load balancer. It acts like a team of servers ready to handle requests.

beginner

What is the purpose of a health probe in Azure Load Balancer?

A health probe checks if the backend servers are healthy and able to respond. It helps the load balancer send traffic only to healthy servers.

intermediate

How does a health probe determine if a backend server is healthy?

The health probe sends regular requests (like pings or HTTP checks) to the backend server. If the server responds correctly within a timeout, it is healthy.

intermediate

Why is it important to configure health probes correctly?

Correct health probes prevent sending traffic to servers that are down or slow, improving reliability and user experience.

intermediate

Can backend pools include virtual machines from different availability zones?

Yes, backend pools can include VMs from different availability zones to improve availability and fault tolerance.

What does a backend pool in Azure Load Balancer consist of?

A Network security groups

B Storage accounts for data backup

C Virtual machines or instances that receive traffic

D Azure Functions

Backend pools are groups of VMs or instances that handle incoming traffic from the load balancer.

What is the main role of a health probe?

A To check if backend servers are healthy

B To store user data

C To encrypt network traffic

D To create virtual machines

Health probes monitor backend servers to ensure they can respond to requests.

If a backend server does not respond to a health probe, what happens?

A Traffic is doubled to that server

B The server is automatically deleted

C The server is restarted

D The load balancer stops sending traffic to that server

The load balancer avoids sending traffic to unhealthy servers to maintain service quality.

Which protocol can health probes use to check backend servers?

A TCP, HTTP, or HTTPS

B FTP only

C SMTP only

D SSH only

Health probes can use TCP, HTTP, or HTTPS protocols to verify server health.

Why include VMs from different availability zones in a backend pool?

A To reduce storage costs

B To improve availability and fault tolerance

C To increase CPU speed

D To simplify network security

Using multiple availability zones helps keep services running even if one zone fails.

Explain what a backend pool is and why it is important in Azure Load Balancer.

Think of a backend pool as a team of servers ready to handle user requests.

Describe how health probes work and their impact on load balancer behavior.

Health probes are like health checkups for servers to keep traffic flowing smoothly.