Load Balancing

Load balancing efficiently distributes the incoming traffic across multiple servers — it balances the incoming traffic load in the most coherent and orderly way. Load balancing is a solid solution to distribute the growing workload and have a back-up plan in case of a failure.

In the world of ever-growing online traffic, modern websites and applications have to handle thousands of simultaneous requests and respond to them in a timely manner, giving the user the right information. Providing optimized traffic distribution, service availability and a quick response is crucial.


Load balancing allows to spread out traffic across different servers in a server farm (server cluster) — a large group of servers put together for better accessibility and functioning. In case of individual failure, these servers provide for each other. The device which routes this network or application traffic is called a load balancer.


A load balancer is the key element in load balancing. It acts as a traffic controller and distributes the network traffic efficiently and evenly, to avoid overloading particular resources and causing failure. A good load balancer significantly increases the speed of processing user requests, and access to websites, databases and applications.

To understand a load balancer and its importance, let us take a look at the infrastructure of load balancing.

Any load balancer is positioned between the client (user) devices and the servers. It receives and spreads out the incoming requests among the servers based on the server’s capacity to fulfill a certain incoming request. It detects the health of a server among the available servers and doesn’t send requests to an unhealthy server.


In any case, the user sends a request to reach a certain address / database / application linked to an IP address.
The load balancer traffic distribution depends on the load balancing algorithm used — how the load balancer checks the backend server where to send the traffic.


Most common load balancing algorithms:

• Round Robin. User requests are distributed across the servers sequentially, depending on the servers’ availability. With load balancing round robin, each user request is forwarded to a different server based on the rotating list. The benefit of round robin is that it is easy to implement.
• Weighted Round Robin. Each server is assigned a weight corresponding to the server’s capacity. Server with higher weights will receive more user requests. For example, if the server A is assigned a weight of 10, and the server B is assigned a weight of 5, the load balancer will transfer 10 user requests to the server A and 5 user requests to the server B.
• Least connection. Each new request is sent to the server with the fewest clients’ connections. This method takes into account the connections that already exist on the server and sends the next request that comes in to the server with the least requests.
• Sticky session This algorithm is also called session persistence. Certain client is linked to a certain server for the duration of the whole session. Once the link has been established by the load balancer, every request that the user sends will always go to the same server until the user finishes the session. The benefit of this algorithm is that it allows to optimize speed, experience and network resources.
• Least response time. This algorithm is based on the time the server takes to respond to a health monitoring request. This time will define the server load and the expected user experience. Based on this, the load balancer will send the user request to the server with the least response time.
• IP Hash. The client’s IP address determines which server the client’s request will go to.
  

Load balancing relies on logic, efficiency, speed and optimization for both the client and the service provider. It is a simple practice which comes with a lot of advantages for the workflow.

Better performance. Load balancers reduce the load on web servers and optimize the traffic, for faster speed and better user experience.
Scalability. The more your solution grows, the more people will be visiting it, and their quantity will impact the speed. With a load balancer, you have access to multiple servers and if there is a traffic spike, a good load balancer will know how to properly distribute the traffic and give your users the experience they deserve.
Availability. Even if one server fails, the rest remain available for your clients.
Consistent high-quality user experience with high speed. Load balancer’s main task is to lower the stress on the servers, optimize the flow and improve the speed of your solution.
Predicting bottleneck scenarios. Certain software balancers can analyze the requests by using predictive analytics to foresee traffic bottlenecks. Like that, they can anticipate the load distribution before the bottleneck happens.
SSL decryption. If your solution has SSL certification, your servers have one more job to do. When a request goes to the SSL website, it is already encrypted, so the servers have to decrypt it before they respond to the request. A load balancer can decrypt the data for more efficient processing time.
IT flexibility. If, for example, your developers need to take down a server for maintenance, the load balancer will simply redirect the traffic to a different server without stopping your website / application / solution.
Redundancy. When working with a group of different servers, load balancing also provides redundancy. If there is a failure in one of the servers, load balancing will direct the request to the functioning servers, in order not to impact the user experience.

New websites, applications and other solutions require a load balancer, especially if you are planning on growing, scaling and adjusting your business. The best load balancer is the one that handles the traffic load so smoothly and quickly, that the clients have no idea what is going on behind the scenes.


A good and efficient load balancer:

• Can manage very high loads of traffic
• Can adapt according to the growth of your business – scalable and flexible
• Can provide unlimited backends — as much as your business needs

An efficient load balancer like Scaleway Load Balancer helps you distribute traffic from clients and improve the client experience on all the levels. How?

1. Scaleway Load Balancer picks the best algorithms available. Based on the incoming traffic, available servers, requests and other criteria, it distributes the traffic load in the most efficient and logical way.
2. You can manage your traffic loads. Simple and efficient, the Scaleway Load Balancer is easy to manipulate via your Scaleway console. Add as many servers as necessary to avoid dips in case of increasing traffic.
3. Scaleway Load Balancer adapts to your business every step of the way. Again, with the Scaleway console, you can easily adjust the number of servers to ensure continuous availability of your solution.
4. Unique Multicloud system. You can build a decentralized infrastructure on different cloud servers and stay independent from one single platform.
5. Scaleway Load Balancer guarantees a sold bandwidth of 4Gbit/s. It is the only cloud provider today to offer such high bandwidth continuously.
6. You get an unlimited amount of backends, as many as you need to make sure your solution works smoothly.

Easy to use and manipulate through the dedicated Scaleway console, the Scaleway Load Balancer remains the best option on the market today to optimize your traffic load, scale your solution accordingly and take a break while it takes care of the user requests for you.