Bret Piatt

Many people seem to think “cloud” is just off-premise “virtualization”.  Cloud comes in a few flavors and I’ll argue that you can have “private cloud” either hosted off-premise in a provider’s facility or in your own.  The fundamental difference between cloud and virtualization is the goal of cloud is to automate provisioning (this applies to IaaS, PaaS, and SaaS) and the goal of virtualization is resource utilization optimization.  You can (and many providers do) use virtualization as the basis for building a cloud but it is not required.

If we take a look at the Reductive Labs presentation from OpsCamp slide 3 illustrates the primary benefit of cloud.  Cloud helps companies even if their minimum unit of work is larger than a single host machine where virtualization just adds overhead in that case.  The difference between “cloud” and “grid computing” or HPC is that grid/HPC process jobs in a batch manner rather than serve interactive applications.  You can build a compute grid on top of a cloud but not vice versa.

Other folks are saying “private clouds can’t exist because you can’t have rapid elasticity and pay for what you use”.  For a small company you may not be able to have a private cloud but for a large enterprise with many business units you certainly can.  An IT infrastructure BU can provide other organizations in the company all of the requirements of a cloud.

For public cloud to succeed they need to provide all three

Depending on the current utilization across an enterprises infrastructure they may be able to defer spending for a number of years by moving to a fully cloud enabled business.  Right now many departments cling to servers they don’t need because they’re afraid if they release it they’ll never get it back.  With cloud removing that fear resource hoarding ends and many enterprises will have a significant increase in available computing power.

Over the long term if the public computing clouds continue to grow, increase their transparency, and optimize their delivery models it will no longer make financial sense for enterprises to build their own infrastructure.  Public cloud providers will need to prove over the next decade they can deliver on all three corners of the “impossible triangle”.

Cloud computing is a broad term that covers Internet based services that provide SaaS (Software as a service), PaaS (Platform as a service), and IaaS (Infrastructure as a service).  SaaS services are the most commonly used cloud solutions — web based e-mail is the prime example.  The most widely used PaaS offering is probably WordPress.org unless you consider customizing your Facebook profile a very restricted PaaS. IaaS is the newest of the cloud services with the most well known example of Amazon Web Services which includes EC2 (cloud servers) and S3 (cloud storage).

Until Hotmail launched in 1996 we all pretty much had an e-mail client on our own system and potentially had to run our own mail server if we didn’t want to have a mailbox tied to our college or ISP — now almost all of us use any number of SaaS e-mail services.  Many of these e-mail services now include full features that businesses expect such as Rackspace E-mail or Google Apps Enterprise.

Before cloud based services if you wanted to have a website you had to run your own server until GeoCities launched in late 1995 — now PaaS providers from GoDaddy, for low price, to Mosso, for horizontal scale, provide very capable platforms to deploy a website without having your own server.

Now IaaS providers like Amazon, Terremark, and Rackspace are eliminating the need to always deploy and manage dedicated configurations for complex applications.  Before these type of IaaS offerings companies like Twitter would end up with their own datacenters and dedicated infrastructure.  Load testing services from companies like SOASTA would be cost prohibitive to offer.

So what about the title, “For everyone, not everything”?  It sounds like cloud has the capability to do everything now doesn’t it?  In a broad sense, yes, it can do a bit of everything but specific use cases in all service times aren’t a fit for cloud.  In the e-mail world if you want to do offline messaging on an airplane you want a mail client.  At the platform service level perhaps your application runs 10x faster if you can customize a couple of libraries or it just doesn’t work at all without those changes.  The infrastructure offerings force you to re-architect for horizontal over vertical scale to use them effectively.

Many other use cases aren’t a fit for the cloud yet.  Take video rendering as an example; it is much less expensive to buy a video card capable of performing rendering than it is to stream the rendered video over a network as 30 JPGs per second.  Another example is a retail POS system, at least some of the functionality needs to be in the store — you don’t want to stop selling things if network connectivity is lost.  Many more explanatory and reasonable examples abound.

Will cloud ever be the answer for all computing needs?  I doubt it, but over time it will be used to solve more problems because a centrally managed pool of resources provides greater efficiency and flexibility.  An example on this is utility power; we use it almost exclusively now but for a few use cases we still need generators.  Cloud will succeed and it will be adopted for a wider set of use cases over time as it will address those use cases better than previous generation solutions.