Migrating to Cloudware - Guide to Cloud Computing for Business and Technology Managers - page 427

customer- and partner-facing Web Services. Central to the debate were the
challenges around Web Services security.
Cloud has surfaced the very same challenges, especially in the data secu-
rity and privacy arena. Many of the cloud security challenges are those that
have been by and large addressed through SOA and Web Services security
standards and solutions, fundamentally because cloud is so heavily depen-
dent on SOA and Web Services as the means of exposing prepackaged cloud-
enabled resources and capabilities via interfaces that can be discovered,
bound to, and leveraged via an service-level agreement (SLA).
The question of where to begin with cloud revolves around the same inter-
nal versus external debate we had with SOA. In cloud vernacular, this relates
to the various cloud deployment models available—internal private clouds,
external public clouds, and lastly hybrid clouds that blend private and public
cloud capabilities. There are a variety of advantages for starting with each
of the three: public clouds, private clouds, and hybrid clouds. The respective
reasons for beginning your cloud initiative with private, public, or hybrid
cloud deployment models will vary by industry and business need. Every
organization must justify its decision based on tolerance for risk, stance
toward emerging technology adoption, and other factors.
20.3.1 Public Cloud
Public cloud deployments, in which an organization migrates an applica-
tion, its data, or a business process onto a third-party cloud service pro-
vider's platform via the Internet, are excellent ways to begin exploring
cloud computing in a cost-effective and agile rapid time-to-market fash-
ion. Leveraging various cloud offerings from Amazon, Google, Salesforce,
and others is an excellent way to explore what cloud can offer to your
enterprise.
The following is a list of reasons an organization would choose to begin
its cloud computing initiative with a public cloud service:
• Low cost. Public clouds offer a very low cost of entry into cloud com-
puting, which supports a POC or pilot project with limited research
and development (R&D) funding.
• Cloud solution variety. There is a wide variety of cloud-enabled
resources to assemble into complete cloud solutions, from virtual-
ization and cloud operating system (OS) or platform technologies
to Platforms-as-a-Service (PaaS) and Software-as-a-Service (SaaS)
offerings.
• Low risk. An organization can quickly experiment with cloud com-
puting solutions with minimal risk exposure.
• Pay for what you need/use. Public clouds are based on a completely
variable, utility cost model, whereby once the initial project has