Azure Load Balancing Documentation

Azure Load Balancing

Azure Load Balancer is a high-performance, low-latency Layer 4 load balancer that distributes inbound and outbound traffic. It can load balance traffic across multiple virtual machines and scale sets.

Key Concepts

Load Balancing Rules: Define how incoming traffic is distributed to backend pools.
Backend Pools: A collection of virtual machines or virtual machine scale sets that handle the traffic.
Health Probes: Monitor the health of backend instances to ensure traffic is only sent to healthy servers.
Load Balancing Algorithms: Azure Load Balancer uses a hash-based distribution algorithm.
High Availability: Built-in redundancy for robust application availability.

Types of Load Balancers

Azure Load Balancer

A global, fully managed Layer 4 (TCP/UDP) load balancer. It provides high availability and scalability for your applications. It can be deployed as Standard or Basic SKU.

Standard SKU: Offers advanced features like availability zones, outbound connectivity, and integration with other Azure services.
Basic SKU: A more cost-effective option for simple load balancing scenarios.

Azure Application Gateway

A web traffic load balancer that enables you to manage traffic to your web applications. It offers Layer 7 (HTTP/HTTPS) load balancing capabilities, including cookie-based session affinity, URL-based content routing, and SSL termination.

Azure Front Door

A scalable and highly available cloud network service that provides global load balancing and dynamic website acceleration. It is designed for web applications and provides features like SSL offloading, cookie-based session affinity, and URL path-based routing.

Common Use Cases

Distributing traffic across multiple web servers for high availability.
Scaling applications by adding or removing backend instances.
Enabling health checks to ensure traffic is only sent to healthy resources.
Providing a single point of access for a distributed application.
Improving application performance through global traffic distribution (with Front Door).

Getting Started

To configure Azure Load Balancer, you can use the Azure portal, Azure CLI, PowerShell, or ARM templates. Here's a basic example using the Azure CLI to create a Standard Load Balancer:

az network lb create \
    --resource-group myResourceGroup \
    --name myLoadBalancer \
    --sku Standard \
    --frontend-ip-name myFrontDoor \
    --private-ip-address 10.0.0.5

For detailed configuration steps and advanced scenarios, please refer to the official Azure Load Balancer documentation.

Azure Documentation