"Cloud computing is the evolution and convergence of many seemingly independent computing trends," Sam Charrington, VP of product management and marketing at Appistry, told a standing-room only LinuxWorld Expo session today. A laundry list of these trends includes commoditization, Internet delivery, virtualization, grid computing, SOA, data center automation, SaaS, PaaS, IaaS, DaaS, utility computing, distributed computing, Web 2.0, IT outsourcing, and storage.Cloud computing's ecosystem in the future will include Google-like public clouds as a platform for applications, and virtual private clouds, which are third-party clouds, or segments of the public cloud with additional features for security, compliance, etc. (for HIPPA medical record compliance or SOX accounting standards, for example.)

Charrington said that the data center of the future also will include private (internal) clouds, which will be an extension of virtualization and used primarily because of their capital or operational efficiencies. "For some applications, data just won't leave the enterprise," he assured the mixed audience of infrastructure administrators, developers, and IT managers. Charrington then walked through a three-tiered cloud technology stack. The bottom tier was a commodity infrastructure of x86, blades, and 10-GbE hardware; a higher virtual machine tier of VMWare or other virtualization vendor software using hypervisors that speak the new Open Virtualization Format (OVF), a cross-vendor format for virtual machines. Another tier is the VM Orchestration tier using key technologies such as Eucalyptus, Enomalism, OpenNebula. At the top of the stack lie the cloud applications and platform.

Charrington cautioned against seeing cloud computing as some kind of panacea for SOA problems since "simply pouring more server cycles on the fire won't solve fundamental mistakes in design." He also quoted a Forrester Research report to the effect that, while leveraging most public clouds is relatively easy, developer or IT administration savvy is required. Amazon EC2, for example, provides a place to scale but no services that automatically scale your application or ensure application availability.

In summary, Charrington said that cloud computing is not for the faint-of-heart. To get ready for cloud computing, organizations need to develop these kinds of proficiencies:

• Virtualization and SOA: "This is the basic blocking and tackling of CC"

• Get familiar with public clouds like Amazon's EC2, GoGrid, etc.

• Study the Eucalyptus project if you're really adventurous

• Explore cloud application platforms

• Check out the Appistry EAF Community Edition platform

• Inventory applications for "cloud-readiness"

• Where might you already be there?

• Convene a task force to migrate a small number (1 to 3) of applications

• Your task force should include an architect, a developer, and someone from operations

For more on cloud computing, see:

Sam Charrington's blog, CloudCamp: Cloud Google Group

InformationWeek has recently developed a "Guide To Cloud Computing" that describes the cloud computing strategies of Amazon, Google, Salesforce.com, and five other leading vendors. The report can be downloaded here.