We have already talked about load balancing. You can read the previous article HERE. Briefly explained, the traffic on the internet is constantly increasing. There are more devices connected and the data that circuit is more too. In order to manage all of this load, you need a load balancer that distributes it among the servers to reduce the load. Now we will focus just on one method to do so – Round Robin.
Round Robin Load Balancer
This load balancer is the most commonly used because of its simplicity. Its implementation is rather straightforward. It is a distributor that redirects the traffic from different users to the servers in order. Let’s see an example. Imagine you have 6 users (u1, u2, u3, u4, u5 and u6) who want to connect and you have 3 servers (s1, s2 and s3). U1 will connect to s1, u2 to s2, u3 to s3 and it will start all over again u4 to s1, u5 to s2 and u6 to s3. Can you guess to which will it connect the next user 7? Yes, it will connect to s1.
It takes into account just when somebody wants to connect. Nothing more. It will definitely serve as a load balance, based on this logic, but ignore all other parameters. So you will have reduced load on the network, but you can have different problems.
Maybe your servers are not equal. Imagine server 1 (s1) is a lot faster than the rest. With more RAM, better CPU, etc. It will still receive the same traffic as the rest which are weaker. It is not the most efficient scenario. For that reason, Round Robin works best with the same configuration of servers.
Weighted Round Robin (WRR)
This variation of Round Robin takes into account the previous case, where one server is better than the rest. Imagine the s1 is twice more powerful than s2 and s3. We will assign it higher weight because it can handle a more significant load. Because we did this, it will get more traffic.
Following the example, u1 will connect to s1, then u2 will again connect to s1. This is the main difference. U3 will connect to s2, u4 to s3, then again u5 to s1 and u6 to s1. U7 will connect to s2.
There is another scenario where Weighted Round Robin can be useful. Maybe your servers are similar, but you have more important information in one, you want it to have less weight. So, it that case you assign higher values to the rest of the servers. This way they will handle more load and your essential server will have less work and less chance to crush.
Can I use Round Robin DNS with CouDNS.net?
You can use Round Robin DNS in every one of our plans, including the free plan. You can try it out HERE.