Database Reference
In-Depth Information
Deployment Models
In addition to describing service models, NIST also lists four models for deploying cloud services. Let's look at
them quickly:
Public cloud
: The cloud provider builds and operates the cloud infrastructure for use by
the general public. This infrastructure exists on the premises of the cloud provider, and the
provider manages the access control and potential pay-per-use model for consumers.
Example: Box and Dropbox offer a certain amount of online storage for free to the public,
and charge for storage beyond that limit.
Private cloud
: The cloud infrastructure is provisioned for exclusive use of lines of business
or branches within a single organization. Usually the IT department of the organization
builds and operates the private cloud (or enterprise private cloud).
Example: Oracle Global IT offers development and testing cloud infrastructure for Oracle
employees worldwide. However, in some cases the cloud infrastructure may be owned and
operated by a third-party vendor that manages the private cloud exclusively for a single
organization.
Community cloud
: The cloud infrastructure is provisioned for exclusive use by a specific
community of consumers from organizations that have shared goals and concerns.
Example: Many federal and state organizations share resources through a cloud
infrastructure.
Hybrid cloud
: Organizations may decide to deploy certain key applications and data in
their private cloud, but other applications in a public cloud. In case of a disaster or heavy
demand on the applications in the private cloud, organizations may decide to temporarily
move part of their workload to the public cloud. This process of temporarily extending
to a public cloud from a private cloud during peak load is called
cloud bursting
. Hybrid
cloud infrastructure is a combination of a private and public cloud (and/or community
cloud) that is connected by standard or proprietary technology for data and application
portability.
Enterprise Private Cloud
The rest of this chapter focuses on enterprise private cloud infrastructures managed by EM12c. However, a public,
community, or hybrid cloud infrastructure provider can also decide to use EM12c for managing their entire cloud
lifecycle. For example, Oracle uses EM12c to manage its public Oracle Cloud.
As mentioned earlier, the IT department of an enterprise usually becomes the cloud service provider in charge
of the enterprise private cloud and its associated deployment model.
As you can see in Figure
5-1
, the cloud users in the business units get more value when they move horizontally from
IaaS to PaaS and then to SaaS. IaaS cloud users within the enterprise are responsible for databases, middleware, and
development and operation of end-user applications on top of the cloud infrastructure offered by their IT department.
If the IT department offers PaaS, cloud users will be responsible only for development, testing, and operations of
their applications, while IT takes care of management and operations of the software platform and the underlying
infrastructure. Enterprise IT departments will have more up-front investment in establishing a PaaS or SaaS model than
an IaaS model.
