Load Balancing Best Practices: Techniques Every Software Engineer Should Master

Imagine your website or application getting bombarded with traffic from hundreds or even thousands of users at the same time. A single server would buckle under the pressure and your website would come crashing down like a house of cards. But fear not!

This is where load balancers come to the rescue. Load balancers help distribute the incoming traffic across multiple servers, ensuring your website stays up and running, and your users remain happy. So, the next time your website starts to feel the heat, call upon the trusty load balancer to save the day!

Let’s delve into the world of load balancing and explore some of the most popular techniques that are used to distribute incoming requests. These techniques have proven to be effective in ensuring that requests are allocated efficiently across multiple servers, preventing any one server from being overloaded.

So, buckle up and get ready to discover some of the key load-balancing techniques that are essential for keeping your applications up and running smoothly.

1. Round Robin Technique
2. Round Robin weighted Technique
3. IP Hashing-Based Distribution Technique
4. Path-Based Distribution Technique

Round Robin Technique

Round robin technique is the technique in which the load balancer starts distributing the requests from the first server to the nth server and then starts it again. Basically, It goes through all servers in one order either from top to bottom or bottom to top. By using this technique, equal requests could be distributed across multiple servers.

Looking at the diagram above, we can see that there are four servers that are responsible for handling incoming requests. To ensure that these requests are distributed evenly and efficiently, the round-robin technique is being used. With this technique, requests are allocated to each server in sequential order, ensuring that no server is overloaded with too many requests. By distributing the requests equally among all servers, this approach helps to maintain a balanced workload and prevent any one server from becoming overwhelmed.

Round Robin Weighted Technique

This technique almost uses the same approach to distribute the requests but it has a weight attribute, by which we can specify that a specific server could handle multiple requests per second efficiently. So, using the weighted attribute we could distribute traffic according to the server's capacity.

In the diagram above, there are four servers tasked with handling incoming requests. However, the second server is considered the most efficient, with the capability of handling three requests per second. To account for this difference in efficiency, the second server has been assigned a weight of three, while the other servers retain a weight of one. By doing so, the load balancer can ensure that requests are allocated in a way that takes into consideration the relative capabilities of each server, leading to more efficient use of resources and improved overall performance.

IP Hashing-Based Distribution

In this technique, the incoming request’s client IP address is used as a hash key to route the traffic to the same server till the server is available. This technique is known as IP Hashing based distribution. There are many algorithms that are built to use this technique.

It can be seen in the above diagram, that the load balancer is using the IP hashing technique in which it takes the request’s client IP and put it in the hashing function to create a unique hash key. Then by using the unique hash key the request will be allocated to the same server every time it hits the load balancer because the hash of the same value will always be the same.

Hashing is a one-way process.

IP Hashing technique is mostly very useful when you are caching something on the same server. So, that this allows the request to go to the same server every time. It would increase the cache hits.

Path-Based Distribution Technique

Using this technique, the load balancer distributes the requests to the server according to the path of the requests. We can deploy our services to different servers and sets their path in the load balancer. Like we deploy an authentication service to server 1, the load balancer will always send the authentication request to the specific server.

This helps ensure that our system remains up and running effectively, even in the face of potential disruptions. By leveraging this approach, we can improve the overall reliability and resilience of our system, and provide a better experience for our users.

In the example, we demonstrated how we can use a load balancer to route requests to specific servers based on their paths. This approach essentially turns the load balancer into an API gateway, as it becomes the central point for handling incoming requests and directing them to the appropriate server.

By leveraging this technique, we can streamline our system architecture and ensure that requests are always routed to the correct service, without having to manually manage the routing logic for each individual service. Overall, using a load balancer as an API gateway can simplify our system architecture, improve performance, and enhance the overall user experience.

Summary

In this article, we have discussed the different techniques to handle the traffic on the servers. Each technique has its own use cases. There are many other techniques out there but these are the common and more effective ones. In the end, it all depends on the requirements of your application.

Follow me

Medium:?https://medium.com/@asimhafeez

If you found this article helpful, don’t forget to give it a clap ??.