Now we are going to explore something that a few people know – DNS load balancing.
You have probably heard about cache plugins and CDN (Content Delivery Network). Now we are going to talk about another network element that increases the speed by managing the DNS requests faster than a single server. It will boast the first step of someone’s visit to a site and redirect the traffic for better performance.
What is DNS load balancing?
DNS load balancing is a technique for administrating the traffic of a hostname. Many of these DNS load balancers are smart. They use different criteria, analyze the traffic, decide to let it go or stop it, and redirect it to another server based on current load or another parameter.
The DNS load balancer is responsible for the redirection of requests of DNS records. It could work together with a complete CDN. That way, the system will not only direct the DNS traffic fast but also to provide cached data like photos or videos directly to the users.
The load balancer can be set to administrate the traffic based on:
- Location of the query. Suppose you are using a Traffic Director or GeoDNS. In that case, your DNS could understand where the traffic is coming and redirect to a particular IP address that will provide better overall performance.
- If a server is busy. The traffic can also be managed based on the occupation of the servers. That way, if a server is already too busy, the queries could go to another DNS server (closest next one), and the network will continue to function.
- Based on the arrival of the query. There is a very basic balancing method, where the queries go to another server, based just on the time of their arrival. The first goes to one, the second to two, and so on, then it starts again.
- Weighted balancing. It could be based on the server’s computing power or another value, which determines which server should get more traffic.
There are more types and combinations, especially with weighted balancing methods, but these are the basic ideas behind load balancing.
Why does DNS load balancing matter?
There are two main purposes to implement DNS load balancing:
- Speed. The most obvious reason is the increased speed. There is no doubt about it. If there is a DNS network of servers with different locations around the globe, your client will get their DNS queries resolved much faster. The speed is a serious factor for SEO, so you definitely can get an edge over your competitor with a well-built DNS balancer.
- Security. As we already mentioned, it could analyze the incoming traffic. It can check the packets of data for errors and stop malicious attempts to poison your DNS server. It could prevent serious problems that could lead to data breaches, phishing attacks to your clients, downtime, and more.
- Reliability. As the name suggests, it balances the load. Managing the traffic between the different DNS servers can stop not only DDoS attacks but could be useful even in normal situations. Imagine you have a promotion on your site, and you are expecting a peak of traffic during a particular period. Without extra help, your site could crash, and you will have plenty of angry customers. This could potentially damage your brand strongly.
DNS load balancer is a method of distributing the incoming traffic through the network of DNS servers so that the traffic could be appropriately managed.