I was asked recently about what “ADCs” and “Traffic Managers” actually do, and how they differ from ordinary “Load Balancers,” and I was reminded of how I first learned about it. So in this series of articles, I will cover some of the key features that can make real a difference to your applications.
To begin with – what is a “Traffic Manager?”
A Traffic Manager performs similar functions for a website, that a call management system does in a call center. Think about a customer service rep at a small startup business. His direct-dial number is published in the phone book and he handles customer queries, ranging from account queries, to technical support questions.
Where the trouble starts
As the company begins to become more successful, the volume of calls goes up and customer service levels decrease. The line may be engaged, or the customer service guy may be away from his desk, so calls get missed. He is also open to a all kinds of unwanted calls: wrong numbers, spam calling, nuisance calls are all a risk. What the company needs is a way to control how phone calls are routed to employees.
A call center is a great way to solve the problem, and a company can sit a number of operators on a call management system, to balance the phone calls across the members of staff, and to route particular calls to particular departments. And most importantly, to give them more control, such as stopping calls from certain locations, screening out nuisance calls, and in some cases, to even respond directly to customer inquiries.
How does this work for a website?
In just the same way, organizations may open a web site with a single web server with a public IP address, but they quickly progress to building a farm of web servers with a traffic management system in front. These traffic management systems are sometimes referred to as “Load Balancers” but more commonly as application delivery controllers. Their job is to manage the delivery of the critical applications and services that the business is publishing. You can measure the effectiveness of an ADC by one simple metric, which is the degree of control that the application delivery controller gives you.
In the next article, we’ll look a little deeper at how a powerful ADC such as Riverbed Stingray gives you much greater availability, performance and control of your application services. Meanwhile, check out these other articles, or if you are ready, take Riverbed Stingray for a test drive, with our free Developer Edition: