Load Balancing Strategies and Techniques You Must Know to Improve Network Efficiency

6. Weighted Least Connections

Weighted least connections is a load balancing technique that combines the least connections technique with the weights for each server. This weight can be determined based on various factors, such as server capacity, server performance, or the type of service provided by the server.

How it works:

1. The load balancer receives a request from the client.
2. The load balancer selects the server with the lowest connection-to-weight ratio.
3. The load balancer sends a request to the selected server.
4. The server processes the request and sends the response to the client.

Excess:

• Distribute workloads evenly between servers taking into account the current server capacity, performance, and workload.
• Avoid overloading certain servers.

Deficiency:

• Requires proper weighting for each server.
• The complexity is higher than the least connections technique.

Application Example:

• Web applications with servers of varying capacity and performance, and dynamic workloads.
• Web applications with different types of services, such as static web servers and dynamic web servers.

7. Source IP Hash

Source IP hash is a load-balancing technique that uses the hash of the client’s IP address and the server’s weights to select a server. This technique ensures that all requests from the same client are always directed to the same server, taking into account the capacity of the server.

How it works:

1. The load balancer receives a request from the client.
2. The load balancer calculates the hash of the client’s IP address and the server’s weight.
3. The load balancer selects servers based on the hash value and weight of the server.
4. The load balancer sends a request to the selected server.
5. The server processes the request and sends the response to the client.

Excess:

• Ensures that all requests from the same client are always directed to the same server.
• Improve connection performance and stability.
• Distribute workloads evenly between servers by considering server capacity.

Deficiency:

• If the selected server fails, all requests from the same client will fail.
• The complexity is higher than the IP hash technique.

Application Example:

• A web application with many users who often log in and log out.
• A web application that uses cookies to store session data.
• Web applications with servers that have different capacities.

8. URL Hash

URL hashing is a load-balancing technique that uses the hash of a URL request to select a server. This technique ensures that all requests for the same URL are always directed to the same server, which can improve caching performance and stability.

How it works:

1. The load balancer receives a request from the client.
2. The load balancer calculates the hash of the request URL.
3. The load balancer selects the server based on the hash value.
4. The load balancer sends a request to the selected server.
5. The server processes the request and sends the response to the client.

Excess:

• Ensure that all requests for the same URL are always directed to the same server.
• Improve caching performance and stability.
• Easy to implement.

Deficiency:

• If the selected server fails, all requests for the same URL will fail.
• It does not consider the current server workload or server response time.

Application Example:

• Web applications with a lot of static content, such as images, videos, and JavaScript files.
• A web application that uses caching to speed up page load times.
• Web application with integrated CDN (Content Delivery Network).