A load-balancing and routing solution in Azure requires careful consideration of several factors including traffic type, geographic distribution, and application requirements. Azure offers multiple services to address these needs effectively.
Azure Load Balancer operates at Layer 4 (TCP/UDP) and p…A load-balancing and routing solution in Azure requires careful consideration of several factors including traffic type, geographic distribution, and application requirements. Azure offers multiple services to address these needs effectively.
Azure Load Balancer operates at Layer 4 (TCP/UDP) and provides high-performance, low-latency load balancing for internal and external traffic. It supports zone-redundant configurations and is ideal for non-HTTP workloads requiring regional load distribution.
Azure Application Gateway functions at Layer 7, offering HTTP/HTTPS load balancing with advanced features like SSL termination, cookie-based session affinity, URL-based routing, and Web Application Firewall (WAF) integration. This solution excels for web applications requiring intelligent routing decisions based on request content.
Azure Front Door provides global load balancing and acceleration for web applications. It combines CDN capabilities with intelligent routing, SSL offloading, and WAF protection. Front Door routes traffic to the fastest and most available backend based on latency measurements, making it excellent for globally distributed applications requiring optimal user experience.
Azure Traffic Manager uses DNS-based traffic routing to distribute requests across global Azure regions or external endpoints. It supports various routing methods including priority, weighted, performance, geographic, and multivalue routing. Traffic Manager works well for disaster recovery scenarios and directing users to specific regional deployments.
When recommending a solution, consider these guidelines: Use Azure Load Balancer for internal tier-to-tier communication and non-HTTP protocols. Choose Application Gateway for regional web applications needing advanced HTTP routing features. Select Front Door for global web applications requiring acceleration and edge capabilities. Implement Traffic Manager for DNS-level failover and geographic routing requirements.
Many architectures combine multiple services - for example, using Traffic Manager or Front Door for global distribution while Application Gateway handles regional HTTP routing, and Load Balancer manages internal traffic between application tiers.
Recommend a Load-Balancing and Routing Solution
Why is This Important?
Load balancing and routing are fundamental components of any resilient and scalable cloud architecture. For the AZ-305 exam, understanding how to recommend the right solution is critical because it demonstrates your ability to design infrastructure that ensures high availability, optimal performance, and efficient traffic distribution. Poor load-balancing decisions can lead to application downtime, degraded user experience, and wasted resources.
What is Load Balancing and Routing?
Load balancing is the process of distributing network traffic across multiple servers or resources to ensure no single resource becomes overwhelmed. Routing refers to directing traffic to the appropriate destination based on specific rules or conditions.
Azure provides several load-balancing and routing services:
• Azure Load Balancer - Layer 4 (TCP/UDP) load balancer for internal and public traffic • Azure Application Gateway - Layer 7 load balancer with WAF capabilities for HTTP/HTTPS traffic • Azure Front Door - Global Layer 7 load balancer with CDN, SSL offloading, and WAF • Azure Traffic Manager - DNS-based global traffic routing • Azure CDN - Content delivery network for caching static content
How It Works
Decision Framework:
1. Global vs Regional - Global distribution: Use Azure Front Door or Traffic Manager - Regional only: Use Application Gateway or Azure Load Balancer
2. HTTP vs Non-HTTP Traffic - HTTP/HTTPS: Application Gateway, Front Door - Non-HTTP (TCP/UDP): Azure Load Balancer
3. Web Application Firewall Needed? - Yes: Application Gateway or Front Door with WAF
4. Traffic Manager Routing Methods: - Priority: Failover scenarios - Weighted: A/B testing or gradual rollouts - Performance: Route to lowest latency endpoint - Geographic: Compliance or data residency requirements - MultiValue: Return multiple healthy endpoints - Subnet: Map specific client IP ranges to endpoints
Key Scenarios and Recommendations:
• Multi-region web application with failover: Azure Front Door or Traffic Manager + Application Gateway • Internal application between VMs: Internal Azure Load Balancer • Public-facing web app needing WAF: Application Gateway with WAF • Global application requiring lowest latency: Azure Front Door with performance routing • Static content delivery: Azure CDN
Exam Tips: Answering Questions on Load Balancing and Routing
1. Identify the traffic type first - HTTP/HTTPS points toward Layer 7 solutions; TCP/UDP points toward Azure Load Balancer
2. Look for geographic keywords - Terms like 'global,' 'multiple regions,' or 'worldwide users' suggest Front Door or Traffic Manager
3. Watch for security requirements - WAF requirements narrow choices to Application Gateway or Front Door
4. Consider the routing method - If the question mentions failover, think Priority routing; if it mentions latency, think Performance routing
5. Remember the combination approach - Azure Front Door handles global routing while Application Gateway handles regional Layer 7 features
6. Internal vs External - Internal Load Balancer has no public IP and works within VNets; Standard Load Balancer supports availability zones
7. Cost considerations - Traffic Manager is DNS-based and less expensive for simple global routing; Front Door offers more features at higher cost