Load balancing might sound like a complicated term, but the concept is pretty easy to understand. Everything people see on their phones and laptops works because of the load balancing software that exists on said devices. If not for load balancing, none of your devices would work, and the world might actually come to a stop.
All this might sound dramatic, but it doesn’t make it any less true. Before getting to why load balancers should be used to handle incoming requests on multi-cluster servers, let’s get to what load balancing actually is. It is a traffic mechanism through which incoming traffic is efficiently and methodically distributed over multiple servers. The load balancing software is located between the actual client servers and the backend ones, and this software receives and then allocates the incoming requests to the available server that can fulfill them.
Load balancing software is used in websites with high traffic rates as they are capable of handling millions of concurrent requests from multiple users with great speed without any loss of data in the process.
The types of Load Balancers
As can be understood from this article so far, there exists a software-based load balancer. There is also another type of load balancer, which is hardware-based. The hardware-based load balancer is different from the software-based one. In that, it is a physical machine that contains specialized processors that have software built into it. Software-based load balancers, on the other hand, run on any computing device.
There are numerous advantages to using software-based load balancers in place of hardware-based ones. Some of the most important are as follows:
- Setting up a software-based load balancer is much easier than doing the same with a hardware-based one.
- Software-based load balancers can be configured as per the application’s needs, and the process of configuration is easier than hardware-based load balancers.
- Software-based load balancers are much cheaper than hardware-based ones, and the cost of the former does not increase with the increase in traffic. The software-based load balancers are almost 75% cheaper than their hardware-based counterparts.
- Deploying becomes much easier with software-based load balancers as these can be deployed anywhere, making them much easier to handle and flexible.
- In hardware-based load balancers, it has been seen that the stability of TCP connections takes a hit when the traffic is extremely high. This is not the case in software-based load balancers because they give a great performance.
The Types of Software-Based Load Balancing
There are two types of load balancing software that will be discussed in this article, and people can take their pick from both based on their requirements. These two types of load balancing software are as follows:
Server-Side Load Balancing
When the client wants to establish a connection and requires access to the website, the server-side load balancers are the ones that listen to the port through which the request is made, making these load balancers the actual servers that handle the request. This does not, however, mean that one selected server handles all the incoming requests because that would result in what is called a server overload. These types of software-based load balancers have certain rules configured on them that prohibit overloaded connections. There are two main rules that are configured on server-side load balancers.
The maximum number of connections that can be established from multiple users at any point in time is predetermined. Secondly, a single client (from a single IP address) can only send a certain number of requests. With the help of these configuration rules, requests can be rejected without so much as entry into the server, which helps with no connections being established beyond the set limit. The number of requests the servers can handle is entirely configurable and is determined through a mechanism that is called Throttling.
Client-Side Random Load Balancing
In this type of load balancing software, a number of IP addresses of servers are delivered to the client, out of which a random one (based on an arbitrary algorithm) is selected, and a connection is formed on it. Each server maintains the number of connections that have been formed so that it can remove itself from the list of available servers if the limit is crossed. This number, contrary to server-side load balancing, is determined through the load stress of an application that does not affect the pre-established connections. Only new connections are prevented until there is some space.
These are all that one needs to know about software-based load balancing. It is obviously the better choice, so find one immediately!