How to determine if a cloud model for SharePoint makes sense for you
It's nearly impossible to miss all the buzz surrounding the cloud in recent years. However, there's no clear consensus on what the cloud actually is; the definition changes depending on who you talk to. This confusion exists especially when referring to Microsoft SharePoint cloud services. SharePoint can be an organization's intranet, extranet, document-management environment, records-management space, or full external website. Combined with the complexity of the SharePoint Service application layer, a cloud service could mean many different things to many different people.
In its broadest definition, the cloud for SharePoint refers to a service that allows an external provider to host and manage SharePoint functionality. This provider typically handles much of the administration and maintenance of the environment. This approach provides significant incentives for many organizations -- particularly the promise of reduced overhead, a serious enticement when IT resources are consistently tasked to do more with less. At the same time, the cloud is no panacea and doesn't necessarily work for all organizations. The key to determining whether SharePoint in the cloud makes sense for your environment is first to understand how hosted SharePoint differs from an on-premises SharePoint deployment.
What Is the Cloud?
Ask 100 SharePoint administrators to define the cloud, and you'll likely get 100 answers. Although the catchphrase is used extensively across the industry, there is no one definition. There are many types of clouds, and various services offer cloud options, each of which differs slightly from the others.
For the most part, a cloud service is defined as an IT function that is housed, maintained, and (usually) administered by a third-party. The driver toward cloud services for most organizations revolves around the fact that most modern organizations prefer to focus on their core businesses rather than on the busywork of maintaining IT. This opinion is the guiding principle and main perceived benefit -- mainly, the ability to offload IT to a company that specializes in it -- of cloud environments.
Cloud services come in many shapes and forms: application clouds, infrastructure farms (both shared and dedicated), and private clouds. Each of these cloud options will be described in more detail in the following sections.
Application Clouds
An application cloud is one in which the application layer of the service is offered to users. For SharePoint, this means environments that offer SharePoint sites and their associated document libraries, lists, and other application-level functionality. These types of clouds do not allow any type of low-level, infrastructure-based functionality, such as configuration of service applications in SharePoint (with some exceptions). Typically the most limited type of cloud offering, application clouds are also often the most cost-effective. The economies of scale with this type of cloud allow for massive numbers of small-to-midsized businesses (SMBs) to share the same physical hardware, reducing the total overall cost to each organization.
Several companies with SharePoint offerings can provide application clouds. These companies effectively allow you to host your SharePoint site or sites on their servers for a designated cost. This cost varies depending on the uptime requirements, level of support, amount of stored data, and provided services.
Microsoft provides one more well-known offering in this space, in the form of SharePoint Online, a component of Microsoft Office 365. Office 365 is Microsoft's application cloud offering and includes messaging functionality through Exchange Online, IM capabilities through Microsoft Lync, and the collaboration features of SharePoint Online. (See the sidebar "SharePoint Cloud Vendors" for a list of several third-party cloud providers.)
Figure 1 illustrates the various versions of Office 365, along with their typical list prices (subject to change). All plans include access to SharePoint Online, though some of the lower-level plans (e.g., the K1 and E1 plans) allow only read-only options for accessing content within SharePoint. The decision of which Office 365 plan to choose is complex and depends on the size of the organization, its messaging needs, the type of workers that it includes (i.e., knowledge worker versus kiosk worker) and whether the full Office suite of tools (e.g., Office Professional Plus) is already available or needs to be purchased. Organizations that are interested in purchasing Office 365 should check directly with Microsoft; costs can vary depending on your licensing situation and the particular geographic area in which your organization is based. Indeed, not all locations offer access to Office 365 or some of the other SharePoint cloud offerings.
Figure 1: Office 365 versions
Infrastructure and Private Clouds
Infrastructure cloud options differ from application clouds in that infrastructure clouds typically allow an organization's servers to be hosted and managed by a third-party but administered and provisioned by the organization. The customer's internal network often extends into the third-party cloud provider's network so that the servers within the private cloud can communicate directly with internal servers. This approach allows the full functionality that you'd expected from internal servers but has the cloud-based advantage of outsourcing the power, cooling, and rack-space requirements.
Private clouds are often created on virtualization platforms that allow for quick provisioning and de-provisioning and a flexible systems infrastructure. For example, private cloud providers might allow the customer to provision virtual servers; the provider simply bills back the customer for the processor time, storage, and memory used. This scenario is often useful for organizations that completely virtualize their SharePoint environments. Such an environment is a supported topology that Microsoft outlines as part of its Server Virtualization Validation Program (SVVP).
However, the setup does require special attention to the disk I/O, memory, and processor requirements of SharePoint Server 2010 and Microsoft SQL Server.
