If Load Balancers Are Dead Why Do We Keep Talking About Them?

Commoditized from solution to feature, from feature to function, load balancing is no longer a solution but rather a function of more advanced solutions that’s still an integral component for highly-available, fault-tolerant applications.

Unashamed Parody of Monty Python and the Holy Grail

Load balancers: I'm not dead.
The Market: 'Ere, it says it’s not dead.
Analysts: Yes it is.
Load balancers: I'm not.
The Market: It isn't.
Analysts: Well, it will be soon, it’s very ill.
Load balancers: I'm getting better.
Analysts: No you're not, you'll be stone dead in a moment.

Earlier this year, amidst all the other (perhaps exaggerated) technology deaths, Gartner declared that Load Balancers are Dead. It may come as surprise, then, that application delivery network folks keep talking about them. As do users, customers, partners, and everyone else under the sun. In fact, with the increased interest in cloud computing it seems that load balancers are enjoying a short reprieve from death.

LOAD BALANCERS REALLY ARE SO LAST CENTURY

They aren’t. Trust me, load balancers aren’t enjoying anything. Load balancing on the other hand, is very much in the spotlight as scalability and infrastructure 2.0 and availability in the cloud are highlighted as issues today’s IT staff must deal with. And if it seems that we keep mentioning load balancers despite their apparent demise, it’s only because the understanding of what a load balancer does is useful to slowly moving people toward what is taking its place: application delivery.

Load balancing is an integral component to any high-availability and/or on-demand architecture. The ability to direct application requests across a (cluster|pool|farm|bank) of servers (physical or virtual) is an inherent property of cloud computing and on-demand architectures in general. But it is not the be-all and end-all of application delivery, it’s just the point at which application delivery begins and an integral function of application delivery controllers.

Load balancers, back in their day, were “teh bomb.” These simple but powerful pieces of software (which later grew into appliances and later into full-fledged application switches) offered a way for companies to address the growing demand for Web-based access to everything from their news stories to their products to their services to their kids’ pictures. But as traffic demands grew so did the load on servers and eventually new functionality began to be added to load balancers – caching, SSL offload and acceleration, and even security-focused functionality. From the core that was load balancing grew an entire catalog of application-rich features that focused on keeping applications available while delivering them fast and securely. At that point we were no longer simply load balancing applications, we were delivering them. Optimizing them. Accelerating them. Securing them.

LET THEM REST IN PEACE…

So it made sense that in order to encapsulate the concept of application delivery and move people away from focusing on load balancing that we’d give the product and market a new name. Thus arose the term “application delivery network” and “application delivery controller.” But at the core of both is still load balancing. Not load balancers, but load balancing. A function, if you will, of application delivery. But not the whole enchilada; not by a long shot.

If we’re still mentioning load balancing (and even load balancers, as incorrect as that term may be today) it’s because the function is very, very, very important (I could add a few more “verys” but I think you get the point) to so many different architectures and to meeting business goals around availability and performance and security that it should be mentioned, if not centrally then at least peripherally.

So yes. Load balancers are very much outdated and no longer able to provide the biggest bang for your buck. But load balancing, particularly when leveraged as a core component in an application delivery network, is very much in vogue (it’s trendy, like iPhones) and very much a necessary part of a successfully implemented high-availability or on-demand architecture.

Long live load balancing.