Why do we need load balancing?
With the massive increase of the internet traffic each year, it is getting harder to provide a sustainable service for all the millions of clients without having some downtime. For this purpose, you need to apply a model of load balancing, that will reduce the load caused by the countless users trying to reach your website or use your application.
Another reason why you need to use load balancing is the rising number of DDoS attacks. To evade them you will need to spread the traffic to as many as possible servers that you have. That way, their combined efforts can resist the wave of high traffic.
Hardware load balancer (HLB)
HLBs are the first to appear sometime in the late 90s. They are hardware, which means you need to purchase the device and connect it to your network. HLB distributes traffic across multiple servers depending on the servers’ process power, the connections, usage of resources or randomly.
The hardware load balancers are implemented on Layer4 (Transport layer) and Layer7 (Application layer). On Layer4 it makes use of TCP, UDP and SCTP transport layer protocol details to make decision on which server the data is to be sent.
On Layer7, the hardware forms an ADN (Application delivery network) and passes on requests to the servers as per the type of the content.
DNS load balancing vs. Hardware load balancing
We will compare them in two conditions, with a single data center, and with cross data center load balancing.
In the first scenario, both are very competitive. The main difference is in price. The DNS load balancer can be more accessible because usually it is offered as a subscription. In the case of HLB you must buy it and if you need extra power in the future, the upgrades can come very costly. The DNS service can be scaled easier, just by updating to another plan.
In the second scenario with cross data center, things are similar. It is getting very expensive to create a global server load balancing with the HLB because you need to properly equip every of your data center.
With global in mind, the DNS load balancing has a clear advantage over the HLB with scalability and price. The DNS option has a better failover and easy recovery.
Another advantage of the DNS load balancing is the cost to maintain. The DNS services are mostly offered as Managed DNS, so it requires less maintenance.
Both DNS load balancing and hardware load balancing offer a good solution for distributing traffic. Which one to choose depends on the needs of your company. How tight control you would like to have? How much can you invest? Do you like a subscribe model with small monthly fees or you prefer to put a lot of money every few years to have the top of the notch performance?
We recommend you to try a DNS cloud-based load balancing, like our GeoDNS.
It is cost-effective, easily scalable; you can use multiple geolocation target options and have protection from DDoS attacks.
Later you can combine it with your own hardware load balancing and create a hybrid for your specific needs.