5.1.4. Implement Azure Load Balancing and Application Gateway

💡 First Principle: Intelligently distributing incoming network traffic across backend resources is fundamental to ensuring high availability, scalability, and enhanced security for applications, preventing any single resource from becoming a bottleneck.

Scenario: You need to deploy a complex web application. It has an internet-facing frontend, internal backend services, and requires protection against common web exploits. You need to distribute traffic efficiently to all these components.

This task delves into the practical application of Azure's traffic management services. You'll explore how to:

• Configure Internal and Public Load Balancers: Distribute traffic based on whether it's internet-facing or internal.
• Configure Load Balancing Rules: Define how traffic is directed to backend resources.
• Configure Application Gateway Listeners, Rules, and Backend Pools: Manage web traffic with advanced Layer 7 routing.
• Configure Web Application Firewall (WAF): Protect web applications from common web exploits.

Mastering these concepts is crucial for the AZ-104 exam, as it assesses your ability to implement scalable and highly available networking solutions.

⚠️ Common Pitfall: Choosing the wrong type of load balancer for the workload. For example, using a Layer 4 Azure Load Balancer when you need Layer 7 features like URL-based routing or SSL offloading.

Key Trade-Offs:

• Performance/Simplicity (Layer 4) vs. Features/Intelligence (Layer 7): A Layer 4 load balancer is faster and simpler but less intelligent. A Layer 7 load balancer offers advanced features but has slightly more overhead.

Reflection Question: How do Azure's load balancing solutions (Azure Load Balancer, Azure Application Gateway), through their various components and configurations, collectively ensure high availability, scalability, and security for your applications by intelligently distributing network traffic?