What are Different load balancing techniques used by AWS

Load balancing algorithms play a crucial role in ensuring the efficient and reliable distribution of incoming network traffic across multiple servers or resources. They are essential components of modern networking architectures, helping organizations optimize performance, enhance fault tolerance, and ensure high availability for their applications. These algorithms can be broadly classified into two categories: static load balancing and dynamic load balancing.

Static Load Balancing:

Static load balancing algorithms follow fixed rules and do not consider the current state of the servers when distributing traffic. They operate independently of the server's capacity or workload. Here are some examples of static load balancing methods:

1. Round-Robin Method:

   In this method, a Domain Name System (DNS) server maps website names to multiple servers in a rotating or round-robin fashion. Each time a client request is received, the DNS server returns the IP address of the next server in the rotation. This evenly distributes traffic among the servers.

2. Weighted Round-Robin Method:

   Similar to the round-robin method, servers are assigned different weights based on their priority or capacity. Servers with higher weights receive a larger share of incoming traffic, ensuring that more powerful servers handle a higher load.

3. IP Hash Method:

   The load balancer uses a hashing algorithm on the client's IP address to map it to a specific server. This method ensures that requests from the same client are consistently sent to the same server, which can be useful for maintaining session state.

Dynamic Load Balancing:

Dynamic load balancing algorithms take into account the current state and capacity of the servers before distributing traffic. They provide a more sophisticated approach to load balancing. Some examples of dynamic load balancing methods include:

1. Least Connection Method:

   The load balancer monitors the number of active connections on each server and directs traffic to the server with the fewest connections. This approach distributes the workload evenly across the available servers.

2. Weighted Least Connection Method:

   Similar to the least connection method, servers are assigned different capacities or weights based on their capabilities. The load balancer directs traffic to the server with the least number of connections adjusted for its capacity.

3. Least Response Time Method:

   This method considers both the server's response time and the number of active connections. The load balancer directs traffic to the server that can provide the fastest response, optimizing user experience.

4. Resource-Based Method:

   Servers are equipped with agents that continuously monitor their resource utilization, such as computing capacity and memory. The load balancer uses this information to make informed decisions and distributes traffic to servers with available resources.