How Azure Load Balancer Works

Azure Load Balancer

Azure Load Balancer allows us to scale our applications and create highly available services. Azure load balancer allows you to distribute traffic to your backend virtual machines. An Azure load balancer provides high availability for your application. The Azure load balancer is a fully managed service itself.

Azure Load Balancer includes a few key components. These components can be configured in your subscription through the Azure portal, Azure CLI, Azure PowerShell, Resource Manager Templates or appropriate alternatives.

Following components play and important role in working of Azure Load Balancer. These are Frontend IP configuration The IP address of your Azure Load Balancer. It's the point of contact for clients. These IP addresses can be either: Public IP Address Private IP Address The nature of the IP address determines the type of load balancer created. Private IP address selection creates an internal load balancer. Public IP address selection creates a public load balancer. Backend pool The group of virtual machines or instances in a virtual machine scale set that is serving the incoming request. To scale cost-effectively to meet high volumes of incoming traffic, computing guidelines generally recommend adding more instances to the backend pool. Health probes A health probe is used to determine the health status of the instances in the backend pool. During load balancer creation, configure a health probe for the load balancer to use. This health probe will determine if an instance is healthy and can receive traffic. Load Balancer rules A load balancer rule is used to define how incoming traffic is distributed to all the instances within the backend pool. A load-balancing rule maps a given frontend IP configuration and port to multiple backend IP addresses and ports. Load Balancer rules are for inbound traffic only. High Availability Ports A load balancer rule configured with 'protocol - all and port - 0' is known as an High Availability (HA) port rule. This rule enables a single rule to load-balance all TCP and UDP flows that arrive on all ports of an internal Standard Load Balancer. The load-balancing decision is made per flow. This action is based on the following five-tuple connection: source IP address source port destination IP address destination port protocol Inbound NAT rules An inbound NAT rule forwards incoming traffic sent to frontend IP address and port combination. Outbound rules An outbound rule configures outbound Network Address Translation (NAT) for all virtual machines or instances identified by the backend pool.

Ref:-

https://docs.microsoft.com/

https://portal.azure.com

Author :-

Alok