Cloud Computing Info

Infrastructure as a Service

Amazon AWS is the largest of all the IaaS providers. Where SaaS offers a complete application as service and PaaS offers the ability to develop an application, IaaS doesn’t care about the application at all. IaaS provides the underlying hardware and operating system resources to do anything you want. IaaS has also been referred to as Everything as a Service.

IaaS offers CPU, memory, storage, networking and security as a package. IaaS is the virtual machine in the sky. In general, with IaaS, you choose from a range of operating systems (usually some flavor of open source), a size for your hardware (number of CPUs and CPU power) and an amount of storage.

There are a number of successful IaaS providers: Amazon, Joyent, GoGrid and FlexiScale.

Desktops as a Service

Falling some somewhere between software and a platform are Cloud Desktops (also called a Cloud OS). These desktops run inside a browser and are accessible from any desktop with an internet connection.

A cloud desktop offers word processing, spreadsheets, development tools, networking tools and more. While relatively immature at this time, we can expect this market to grow significantly in the coming years, especially as more and more smart phones and ultraportables hit the real world.

Microsoft LiveMesh offers free storage, machine synchronization and a cloud based desktop.

Platform as a Service (PaaS)

The next step up into the cloud from SaaS is the Platform as a Service. While SaaS offers applications for end users, PaaS offers a development platform for developers. Developers do not need to worry about the operating system, storage or hosting. Developers write the code and the PaaS provider provides a very simple method to upload that code and present it on the internet.

The PaaS provider gives provides the hardware, operating system, software upgrades, security and everything else related to the day to day hosting of an application. Most PaaS providers are limited to specific languages and IDEs.

Software as a Service (SaaS)

SaaS is currently the most popular type of cloud computing. Yahoo email, Google apps, zoho, and various other packages like CRM are all instances of SaaS. Application Service Providers (ASP) were the first SaaS providers. ASP was its own buzzword back in the late 1990s and early 2000s.

One of the aspects of SaaS is multi-tenancy or the ability for many customers to share the same service but maintain their own data securely. CRM is the predominant paid SaaS offering but email is, by far, the predominant free SaaS offering.

Any software that is offered over the internet, that runs remotely (where the location is unimportant and unrelated to the user), is a SaaS offering.

Distributed Computing

Distributed computing was one of the first real instances of cloud computing (albeit in reverse). Long before Google or Amazon, there was SETI@Home. Proposed in 1995 and launched in 1999, this program uses the spare capacity of internet connected machines to search for extraterrestrial intelligence. This is sort of the cloud in reverse.

A more recent example would be software like Hadoop. Written in Java, Hadoop is a scalable, efficient, distributed software platform designed to process enormous amounts of data. Hadoop can scale to thousands of computers across many clusters.

Distributed computing is nothing more than utilizing many networked computers to partition (split it into many smaller pieces) a question or problem and allow the network to solve the issue piecemeal.

Another instance of distributed computing, for storage instead of processing power, is bittorrent.

So what is cloud computing? Defining the term “cloud computing” has become an industry unto itself. Is it utility computing? Is it an application service provider’s offering? Is it virtual machines in the sky? All of these are correct depending on who you ask.

Core features of cloud computing are scalable, centrally managed and accessible via the internet. Cloud computing boils down to running software on someone else’s robust hardware in a data center somewhere else. Let’s think about that for a minute: someone else’s software on someone else’s hardware in someone else’s data center.