Load balancing is a hot topic in the web hosting industry as the technology is being increasingly used in server farms and shared hosting environments. Its purpose is to fine tune computer systems and networks in a manner that better evenly distributes data and processing across available resources to prevent a single device from being overloaded. Some of the busier websites utilize two or more servers in a load balancing scheme. Therefore, if one is overwhelmed, traffic is forwarded to another with more capacity.
Common Types of Load Balancing
The process of load balancing is one that can be achieved in a variety of ways. If this is a technology you are interested in, it is best to know what methods are available to you. After learning a little more about the types of load balancing, you will should be able to better determine which option works best.
Round Robin DNS Load Balancing
One of the earliest adopted techniques, round robin DNS load balancing uses the round robin feature built into the BIND DNS server to facilitate cycles through the IP addresses corresponding to a farm of servers This is one of the easiest and most inexpensive methods to implement. The downside to this type of load balancing is that the DNS server doesn’t have any knowledge of the server’s availability. Therefore, there is a possibility that data could be continuously forwarded to an unavailable server. There is also a chance that an IP address will be cached by other nameservers and not sent to the server designated for load balancing.
Hardware Load Balancing
With hardware load balancing, TCP/IP packets are routed by a device to numerous servers in a cluster, a method that leverages circuit level gateway to route traffic. This method is said to create a powerful topology with a high level of availability. The one big drawback is a cost that is often considerably higher than other methods.
Software-based Load Balancing
The software-based variation is the most commonly used load balancing method. These type of load balancers are typically integrated as components in proprietary web servers and application server platforms. This technique is more configurable and offers the ability to implement intelligent routing based on various input parameters. In many cases, software-based load balancing requires additional hardware be provided to isolate the load balancers.
Narrowing Your Options
The decision of choosing a load balancing configuration based on hardware or software should be made on one’s particular needs. For instance, if your website only requires load balancing to serve HTML pages or lightweight dynamic, data-driven pages, the round robin method should be sufficient. On the other hand, if your traffic and data processes are more demanding, you would probably get the best performance out of the more advanced software or hardware methods. Whatever method you take, keep in mind that the load balancer should be able to deliver intelligent monitoring to evenly distribute the load. Depending on your situation, different techniques can better direct the loads to the servers that are more capable of handling them than others in the cluster.