What is Azure Load Balancer?
Azure Load Balancer is a Layer 4 load balancer that distributes incoming TCP and UDP traffic across multiple backend resources. The service enables high availability by distributing load and automatically removing failed instances from the pool.
Azure offers two variants: Basic Load Balancer for simple scenarios and Standard Load Balancer for production workloads with advanced features like zone-redundant frontend, outbound rules, and 99.99% SLA.
Core Features
- Layer 4 load balancing for TCP and UDP traffic
- Health probes for automatic detection of failed backends
- Zone redundancy for high availability across Availability Zones
- Outbound rules for controlled outgoing connections
- Session persistence for sticky sessions
Typical Use Cases
Web Tier Load Balancing: Multiple web server VMs share incoming HTTP/HTTPS traffic for better performance and fault tolerance.
Internal Services: Internal Load Balancers distribute traffic between microservices within a Virtual Network without public IP exposure.
High Availability: Critical applications are distributed across VMs in multiple Availability Zones, Load Balancer routes traffic only to healthy instances.
Benefits
- Millisecond latency through native Azure integration
- Scaling to millions of concurrent connections
- No Load Balancer infrastructure management
- Integration with VM Scale Sets for automatic scaling
Frequently Asked Questions
What is the difference between Basic and Standard?
Standard Load Balancer offers zone-redundant frontend, more backend pool members (up to 1000), outbound rules, multi-dimensional metrics, and 99.99% SLA. Basic is free but recommended only for development.
When should I use Application Gateway instead of Load Balancer?
Application Gateway is a Layer 7 load balancer with SSL offloading, URL-based routing, and WAF. Use Application Gateway for HTTP/HTTPS workloads, Load Balancer for other protocols.
How are costs calculated?
Standard Load Balancer: Fixed cost per rule plus costs for processed data volume. Basic Load Balancer is free.
Can I use Load Balancer with AKS?
Yes, AKS automatically creates Load Balancers for Kubernetes Services of type LoadBalancer.
Integration with innFactory
As a Microsoft Solutions Partner, innFactory supports you in implementing scalable network architectures with Azure Load Balancer. We help with design, migration, and optimization.
Contact us for a non-binding consultation on Azure Load Balancer.
