Azure Load Balancer provides several load balancing algorithms that you can choose from to distribute traffic across your backend instances. Each algorithm uses a different method to determine how traffic is distributed, and you can choose the algorithm that best suits your application’s requirements.
Load balancing algorithms that are available with Azure Load Balancer:
Round Robin
The Round Robin algorithm is a simple and effective method for distributing traffic evenly across multiple backend instances. It is often used when backend instances have similar processing capabilities and resources. However, Round Robin does not take into account the current load on individual backend instances, so it may not be the best choice if some backend instances are more heavily loaded than others.
Least Connections
The Least Connections algorithm is useful when backend instances have different processing capabilities or when some backend instances are heavily loaded. By routing traffic to the backend instance with the fewest active connections, new requests are distributed to backend instances that have the most capacity. However, this algorithm may not be the best choice if backend instances have similar processing capabilities or if the load on backend instances fluctuates frequently.
Source IP Hash
The Source IP Hash algorithm is useful for maintaining session affinity in web applications that require user authentication. By using the source IP address of the incoming request to determine which backend instance to route the traffic to, requests from the same client are always routed to the same backend instance. This ensures that session state is maintained and provides a consistent user experience. However, this algorithm may not be the best choice if clients are using NAT or if requests are coming from a large number of unique IP addresses.
Destination IP Hash
The Destination IP Hash algorithm is similar to the Least Connections algorithm, but instead of using the current load on backend instances to determine where to route traffic, it uses the destination IP address of the incoming request. This is useful when backend instances have different processing capabilities or when some backend instances are heavily loaded. However, this algorithm may not be the best choice if backend instances have similar processing capabilities or if the load on backend instances fluctuates frequently.
Conclusion
Azure Load Balancer provides several load balancing algorithms that you can choose from to distribute traffic across your backend instances. Each algorithm has its own advantages and disadvantages, and you can choose the algorithm that best suits your application’s requirements. By understanding the load balancing algorithms available with Azure Load Balancer, you can ensure that your application is distributed efficiently and provides a high level of performance and resiliency.