Category Archives: Computer Basics

No, I’m not talking about the weather here in San Francisco – that’s actually been pretty good. It’s just that everywhere you look here at the Citrix Summit / Synergy conference, the talk is all about clouds - public clouds, private clouds, even personal clouds, which, according to Mark Templeton’s keynote on Wednesday, refers to all your personal stuff:

• My Devices – of which we have an increasing number
• My Preferences – which we want to be persistent across all of our devices
• My Data – which we want to get to from wherever we happen to be
• My Life – which increasingly overlaps with…
• My work – which I want to use My Devices to perform, and which I want to reflect My Preferences, and which produces Work Data that is often all jumbled up with My Data (and that can open up a whole new world of problems, from security of business-proprietary information to regulatory compliance).

These five things overlap in very fluid and complex ways, and although I’ve never heard them referred to as a “personal cloud” before, we do need to think about all of them and all of the ways they interact with each other. So if creating yet another cloud definition helps us do that, I guess I’m OK with that, as long as nobody asks me to build one.

But lest I be accused of inconsistency, let me quickly recap the cloud concerns that I shared in a post about a month ago, hard on the heels of the big Amazon EC2 outage:

1. We have to be clear in our definition of terms. If “cloud” can simply mean anything you want it to mean, then it means nothing.
2. I’m worried that too many people are running to embrace the public cloud computing model while not doing enough due diligence first:
   1. What, exactly, does your cloud provider’s SLA say?
   2. What is their track record in living up to it?
   3. How well will they communicate with you if problems crop up?
   4. How are you insuring that your data is protected in the event that the unthinkable happens, there’s a cloud outage, and you can’t get to it?
   5. What is your business continuity plan in the event of a cloud outage? Have you planned ahead and designed resiliency into the way you use the cloud?
   6. Never forget that, no matter what they tell you, nobody cares as much about your stuff as you do. It’s your stuff. It’s your responsibility to take care of it. You can’t just throw it into the cloud and never think about it again.

Having said that, and in an attempt to adhere to point #1 above, I will henceforth stick to the definitions of cloud computing set forth in the draft document (#800-145) released by the National Institute of Standards and Technology in January of this year, and I promise to tell you if and when I deviate from those definitions. The following are the essential characteristics of cloud computing as defined in that draft document:

• On-demand self-service. A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service’s provider.
• Broad network access. Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).
• Resource pooling. The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. There is a sense of location independence in that the customer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter). Examples of resources include storage, processing, memory, network bandwidth, and virtual machines.
• Rapid elasticity. Capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out, and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.
• Measured Service. Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service.

If you’ll read through those points a couple of times and give it a moment’s thought, a couple of things should become obvious.

First, most of the chunks of infrastructure that are being called “private clouds” aren’t – at least by the definition above. Standing up a XenApp or XenDesktop infrastructure, or even a mixed environment of both, does not mean that you have a private cloud, even if you access it from the Internet. Virtualizing a majority, or even all, of your servers doesn’t mean you have a private cloud.

Second, very few Small & Medium Enterprises can actually justify the investment required to build a true private cloud as defined above, although some of the technologies that are used to build public and private clouds (such as virtualization, support for broad network access, and some level of user self-service provisioning) will certainly trickle down into SME data centers. Instead, some will find that it makes sense to move some services into public clouds, or to leverage public clouds to scale out or scale in to address their elasticity needs. And some will decide that they simply don’t want to be in the IT infrastructure business anymore, and move all of their computing into a public cloud. And that’s not a bad thing, as long as they pay attention to my point #2 above. If that’s the way you feel, we want to help you do it safely, and in a way that meets your business needs. That’s one reason why I’ve been here all week.

So stay tuned, because we’ll definitely be writing more about the things we’ve learned here, and how you can apply them to make your business better.