blog.virtualtacit.com

It has been of great interest to me how the landscape of distributed computing has developed over the last few years. Even though the idea was developed in the late 70’s, it most recently has begun to take lead in the race toward “liberation” as Diane Greene stated at a recent tech conference in Boston, blogged about here. No doubt many tech giants have taken notice of this trend and have been working toward a workable, profitable and stable web computing solution, ie. Amazon’s S3/EC2 , Yahoo!’s Hadoop, IBM Blue Cloud and Google’s AppEngine to name a few. Considering that these models are built on the backs of virtual infrastructure (typically XEN-based) I thought it may be beneficial to explain the differences between the three.

• Cloud Computing is really the way applications are built, delivered, run and maintained in a virtual environment. Surrounding that is the automation of that application, the ability to expand and shrink computational needs and self-recoverability.CC offers a way to extend IT services without having to invest in new infrastructure. Sound familiar? Its no wonder virtualization is the catalyst for this technology. The backend services (storage, networking, security, etc) are abstracted from the end user. The resources are controlled by the provider, the user cares little about where their application lives only about services provided.

• Grid Computing? Well the best known example of this model is SETI (Search for Extra Terrestrial Intelligence). That’s right whether we want to admit to it or not most of us probably at one time or another contributed a sliver of our unused processors toward this cause. The obvious draws toward this trend are the ability to harness large amounts of computing power at relatively low cost. This type of computing power in most situations would be unobtainable due to power, cooling and financial constraints. The use of geographically dispersed commodity nodes to aid in the same computational cause will always have its place and notably will most likely evolve into a pseudo cloud model.

• Utility Computing is ultimately built on some form of computing cloud. It encompasses a metered approach or time sharing of sorts based on actual capacity or resources used. This is generally where your EC2’s and 3Tera’s operate. This business model in essence was built as any public utility, the provider (ie.public utility) is paid for use of its infrastructure. In return it maintains that infrastructure to provide you, the customer, with an acceptable level of service. Again this model goes hand and hand with virtualization as data centers in general are notoriously underutilized and over provisioned.

As these “utility clouds” expand in popularity, the traditional start-up client base will move to enterprise companies looking to disperse their workloads outside of their traditional data center. This will in turn lead toward increased utilization and a greener approach toward computing in general. It will be very interesting to see how this plays out in the forth coming years.