For years now, the load balancing industry has been trying to shift to the new term “application delivery controllers”, or ADC. The argument is that this is a new generation of devices, and they do so much more than load balancers of the past.
I agree, they do more than they’ve done before. From application logic to web application firewalls to VMware integration, modern application delivery controllers do a lot. But they still also load balance. And that’s what everyone calls them.
A rose by any other name. Pictured: Olfactory stimulation vector
Using the term load balancer saves me the conversation: “What’s an application delivery doo-hickey?”
I still call them load balancers because it serves no purpose to rename them.
Since at least 2006 there’s been an effort to rebrand load balancers as application delivery controllers. Gartner has moved to the new term, as have most of the vendors. Marketing has been heavy to rename them. Some vendors even use the term load balancer as a disparaging term for their competitors.
But here’s the problem: We’ve had at least 5 years of marketing, press releases, and events, and still no one (outside of the vendors and specialists) seems to know what an application delivery controller is. When I teach load balancing classes, very few in the class are even aware of the term.
What network administrators, server administrators, and application developers do know is load balancers. When you say “load balancer”, they universally understand what they do and the benefit they provide. Generally speaking, they have no idea what an ADC is.
I have no problem educating on a new term, I’d even help evangelize the term if it made sense. But it doesn’t. Renaming them ADCs adds nothing substantive to the industry, only confusion and an extra conversation.
If I told you I got a new multi-media climate controlled dynamic geographical device, you’d think I’d be some sort of mad scientist. But no, that’s just another name for a car. Cars today do a lot more than cars 50 years ago did, but they’re still cars.
I understand the though behind the attempt to rename them, but I think it’s a mistake. I don’t mind mistakes, but I think its time to own up to the error and start calling them load balancers again.
Technology is complicated enough, we shouldn’t make it more complicated by adding in terms when none are needed.
Tony I think you are half right!
The confusion for me comes from vendors calling their products ADCs when they are actually “just” load balancers. First let me defend myself, I am not a marketeer but a simple Systems Engineer, and yes I have to, on a day to day basis, explain what ADCs are!
You are right in that all the products in our space “do” load balancing, it’s a given. So what makes a product an ADC (we complicate things more here at Zeus by using the terminology Traffic Manager!)?
I believe it is the addition of a powerful scripting language which moves the product out of the HA/Scalability space into the problem solving space which makes the difference.
Unfortunately not every vendor selling ADCs has this capability which is where the confusion creeps in. It’s like Mercedes calling the Smart a truck, yes it has the same base functionality, but it just can’t do all the jobs you need a truck for…
Nick
Tony,
Couldn’t agree more… Can you believe Wikipedia actually removed the entry for “load balancer” ! – Makes me sick….
An ADC or (ADN good grief!) has always been a marketing gimmick.
If you need a particular load balancer feature like a low level scripting language then look in the spec!
Load Balancer gets a billion more hits on Google than ADC, that’s why it costs $25 a click for the top add and ADC is only $3.
</end of rant….
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Hi Nick,
I partially agree. There are differentiators among the load balancing products, and the advanced scripting capability is one of the most important (RuleBuilder, aFlex, iRules) from products that don’t (KEMP, Cisco, etc.) But that capability is the differentiator, not the term ADC.
What may actually be useful is to come up with a generic term for RuleBuilder/aFlex/iRules, and create a definition everyone understands. I was thinking Application Control Language, but the acronym would be ACL and would get lost in the very popular acronym.
The term ADC is confusing, it doesn’t differentiate, and provides absolutely no indication of additional value. I think it’s marketing run amok, and I think that while the idea might have been good, it hasn’t worked. The term ADC is a failure. 6 years on, still no one has any clue what it is. And when I explain it to them, they continue to use the term “load balancer”. Because it’s what everyone is used to.
Tony
Hi Tony,
I was nearly going to concede and let you have this. But the more I thought about it, the more convinced I have become about the difference between a Load Balancer and an ADC!
OK yes it’s marketing, but the aim in this case is to explain how different an ADC is. Maybe, this is where we have all failed, in not getting this across as clearly as we would like.
A load balancer is very much a network focused product. Solving issues such as HA, scalability and performance.
An ADC is an application/business focused product. Solving issues such as how to deliver a consistant level of service to class 1 customers, even when our resource is under pressure. Possibly at the cost of class 2 clients.
Therefore, very often it is a different set of interested parties in an organisation, that utilise the two types of product in our space.
Granted it is a very blurred line in places, but I do think the distinction is important. It is more than just a difference in functionality, but a difference in how these extra tools are implemented, by whom, and for what purpose.
Nick
Hi Nick,
Devices today are evolutionary in terms of functionality, not revolutionary. They added features and features that made sense for where they sit in the data center. We still use VIPs, define real servers, etc. They still sit in the network in the same way they have before.
Are there any devices that are “load balancers” in the old sense? No, of course not. All the vendors have evolved. They all do Layer 4 and 7, they all do SSL acceleration/termination, they all do URL switching, and they all have other additional features. Some more than others, but there’s no clear demarcation point for what is a “load balancer” and what is an “ADC”. It’s all marketing, a useless differentiation that differentiates no one, and in the past 6 years (at least) *no one* but the vendors has bought into the term.
Everyone calls them load balancers. Everyone. The surest way to confuse a data conversation is to throw in the term ADC, because everyone goes “wait, what?”.
Term ADC hasn’t worked. There are lots of reasons why, but at the end of the day it’s a term that still hasn’t caught on. Anywhere. It’s time to let it die.
Tony