Scalability In the Cloud Era Isn't What You Think

Esther Schindler writes "'Scalability' isn't a checkbox on a vendor's feature chart — though plenty of them speak of it that way. In this IT Expert Voice article, Scott Fulton examines how we define 'scalability,' why it's data that has to scale more than servers, and how old architectural models don't always apply. He writes, 'If you believe that a scalable architecture for an information system, by definition, gives you more output in proportion to the resources you throw at it, then you may be thinking a cloud-based deployment could give your existing system "infinite scalability." Companies that are trying out that theory for the first time are discovering not just that the theory is flawed, but that their systems are flawed and now they're calling out for help.'"

Comments

I read the article

[Saint Stephen]

and learned not a damned thing. Classic marketecture speak.

Re:I read the article

[timeOday]

I'll bite, what's the "cloud mess"? In the olden days, we mocked slashdot story submitters who linked to videos because their ISP account, or university account, could never handle it. There wasn't really a way for an individual to share a video with thousands of people. Now we just upload to youtube, and viola, it works. Scalability issue solved. How many computers does it take to accomplish that? Where are they? Are they all in one place? It's a cloud, most of us don't know and don't care. It's good.

Of-course it is a checkbox

[roman_mir]

Scalability is a buzzword that equipment, databases and servers (hardware/software) are sold on. It is as if by adding more weblogic servers to a cluster really makes your application scalable, as if throwing more processors onto a RAID system gives you more parallel ways to read / write the same data etc.

It is all true to an extent and it is all false where it really matters. Applications need to be designed to be scalable and if I learned anything over the past 16 years is that people do not even begin to understand what it means.

The managers and even many 'architects' really think that by throwing some stupid app on a cluster will really solve the scalability issues and so on. But the problem is that it is a very specific problem that can be solved by simply adding cluster nodes without actually properly designing the app. I blame various silver bullets like EJBs, CORBA, RMI, JNDI, BEA, Oracle, IBM and such for promoting this view among the top brass and pulling attention away from working out correct architecture to solve the specific problems that appear in building truly scalable applications.

Application servers and databases are the worst at this, they certainly provide some specific type of scalability solution but because of that, it is almost expected that it does not matter how an app is designed to interact with these, and the design is really on the distant third, fourth, fifth or further place, way behind the deadlines, the politics, the hiring practices etc.

Scalability is like security, it is not a one specific thing it is a way to approach many different issues and problems and even when you think your app is secure in 5 different ways, there is a sixth way in which it is not. Same with scalability: it is not only about multi-threading requests, it is not only about multiple processors for a RAID system, it is about total understanding of how the application is and will be used and adjusting it for various types of usage. Proper design for scalability mixes various approaches, there could be intermediate steps added, back-ground processing added, intermediary storage, separate storage for reading than for saving, various caching mechanisms and synchronization between nodes in a cluster for different caching questions. This could be redefining an algorithm to be less dependent on reading data from slow media. Some things are not supposed to be done in parallel, so certain bottlenecks due to synchronization need to be looked at and solved early on, because these become the Achilles heel - synchronizing on anything at all can defeat a super-fast cluster and make it no better than as a single laptop.

It is a design issue.

I dunno...

[thewils]

That ash cloud from Eyjafjallajokull seems to be scaling pretty good.

Hand wave

[Itninja]

I find that when I speak in my "IT Expert Voice" I get all kinds of things. Even if I am saying gibberish:

"Linda. The malware infecting you CRT is several beta tests behind the best practice of current IPv6 drives. I will need your password to defrag the driver and upload the taskbar to your certification path...Thank you Linda."