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Azure Load Balancers

Azure Load Balancer is a high-performance, highly available network load balancing solution that distributes incoming application traffic across multiple virtual machines or service instances. It provides several layers of network abstraction and allows for the creation of robust, scalable, and resilient applications on Azure.

Load balancing is crucial for:

• High Availability: Ensuring your application remains accessible even if one or more instances fail.
• Scalability: Distributing traffic across multiple instances to handle increased demand.
• Performance: Optimizing response times by directing traffic to available and healthy instances.

Types of Load Balancers

Azure offers different types of load balancing services to suit various needs:

• Azure Load Balancer: A Layer 4 (TCP/UDP) load balancer that distributes traffic based on IP address and port. It supports both public and internal load balancing scenarios.
• Azure Application Gateway: A Layer 7 (HTTP/HTTPS) load balancer that offers more advanced routing capabilities, such as SSL termination, cookie-based session affinity, and URL-based content routing.
• Azure Front Door: A global, highly available, and scalable cloud service that enables you to build, modernize, and scale your web applications and APIs. It provides intelligent traffic acceleration and global load balancing.

Key Features of Azure Load Balancer

• High Availability: Built-in redundancy and automatic failover.
• Scalability: Handles millions of requests per second.
• Health Probes: Monitors the health of backend instances and removes unhealthy instances from rotation.
• Port Forwarding: Allows external access to specific ports on backend VMs.
• Session Persistence (Sticky Sessions): Configurable to ensure requests from the same client session are directed to the same backend instance.
• Integration with Azure Services: Works seamlessly with Virtual Machines, Virtual Machine Scale Sets, and other Azure networking services.
• Network Address Translation (NAT): Supports both inbound and outbound NAT rules.

Common Use Cases

• Deploying multi-tier applications requiring load balancing between tiers (e.g., web servers, application servers, database servers).
• Ensuring the availability of critical services by distributing traffic across redundant instances.
• Scaling applications to meet fluctuating user demands.
• Providing external access to internal applications securely.

Pricing

Azure Load Balancer has a pay-as-you-go pricing model. Costs are based on the number of rules and data processed. For detailed pricing information, please refer to the Azure Load Balancer pricing page.

Next Steps

Explore more in-depth documentation:

• What is Azure Load Balancer?
• Azure Application Gateway Overview
• Azure Front Door Overview