Evolution of Cloud Computing

Enterprise organizations will likely experiment with cloud computing, carefully choosing projects that benefit from cloud’s features and cost benefits as they develop more formal cloud computing strategies.

The phases of the model include:
Test and development: This phase introduces cloud for proof of concept use. During this initial phase, IT becomes comfortable with server virtualization and gains experience with system performance, application response times, and technology stability.

Consolidation: This phase is highlighted by the migration of physical servers to virtual machines typically referred to as P2V. At this point, IT rapidly moves workloads that have been identified as viable candidates and gives them the green light for production usage on the virtualized infrastructure.

Enterprise: This phase is a significant milestone where the business chooses a virtualization platform for mission critical applications, standardizes data protection, implements disaster recovery, automates routine tasks, and meets SLAs. The goal in this phase is a near 100% virtualized data center.

Dynamic: In this phase, the IT infrastructure is tightly integrated with IT and business processes. As
Administrators apply security, performance, and availability policies, the virtualization platform responds automatically without manual interaction. This is the really the beginning of a true private cloud.

Cloud: The cloud or final phase provides a real time consumption model that meets the descriptions and definitions detailed previously. At this phase, business owners only pay for what they consume and can quickly provision and decommission resources as needed. Control shifts into the hands of the application owner, allowing for management of an extremely fluid environment that instantaneously responds to change across distributed resources regardless of whether they are owned or leased from or hosted by a third party. This entire process is completely transparent to the application and its administrators.

Cloud Computing Deployment Models

Just like the cloud services models, cloud computing can be deployed in a number of ways depending upon factors like security requirements, IT skills, and network access. The IT industry has outlined four cloud computing deployment models:

Private cloud: The cloud infrastructure is operated within a single organization. In this case, internal groups such as business units consume resources and services provided by a single internal (i.e., the IT department) or external cloud computing provider.

Community cloud: A community cloud is a superset of a private cloud. The cloud supports the needs of several or an extended community of organizations. Again, community clouds can be built and operated by members of the community or third party providers.

Public cloud: The cloud infrastructure and services are available to the general public. Examples of public clouds include Amazon Elastic Compute Cloud (EC2), Google App Engine, Microsoft Azure or Terremark Cloud Computing services.

Hybrid cloud: The cloud infrastructure amalgamates private or community clouds with public clouds. In this case, private or community cloud services have the capability to extend or “burst” to consume public cloud resources.

Cloud Computing Consumption Model

At the most fundamental level, cloud computing provides flexible real time access to a shared pool of computing resources (e.g., networks, servers, storage, applications, and services). Indeed, one of the main attractions of cloud computing is its capability to provide on demand IT resources and services offering rapid provision and de provisioning as well as “pay by the drink” pricing.

Cloud computing as having the following essential characteristics:

On demand self service: A consumer can unilaterally provision computing capabilities such as server time and network storage as needed. This can happen automatically, without human interaction, system administration, or service provider support.

Broad network access: Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops and PDAs).

Resource pooling: The provider’s computing resources are pooled to serve multiple consumers using a multi tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. There is a sense of location independence in that the customer generally has no control or knowledge over the exact location of the provided resources, but may be able to specify location at a higher level of abstraction. Examples of resources include storage, processing, memory, network bandwidth, and virtual machines.

Rapid elasticity: Capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and then rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.

Measured service: Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported providing transparency for both the provider and consumer of the utilized service.

Cloud Computing Services Model

Cloud based IT resources can be consumed for various reasons in myriad ways. That the IT industry has really rallied around three standard cloud computing services models:

Infrastructure as a service (IaaS): This is really the most basic cloud service model, aligning the on demand resources of the cloud with tactical IT needs. In this way, IaaS is similar to managed services offerings of the Internet era (i.e., hosting services, storage service providers (SSPs), etc.). The primary difference is that cloud resources are virtual rather than physical and can be consumed on an as needed basis. In other words, enterprise consumers pay for virtual machines (VMs), storage capacity, and network bandwidth for a variable amount of time rather than servers, storage arrays, and switches and routers on a contractual basis. Typically, enterprises have no control over the underlying cloud technology. As described above, IaaS can be utilized as a temporary resource or used for years at a time. IaaS prices are based upon two factors: IaaS resource consumption and the duration of use.

Platform as a service (PaaS): Simply stated, PaaS provides the capability to build or deploy applications on top of IaaS. Typically, a cloud computing provider offers multiple application components that align with specific development models and programming tools. For the most part, PaaS offerings are built upon either a Microsoft based stack (i.e., Windows, .NET, IIS, SQL Server, etc.) or an open source based stack (i.e., the “LAMP” stack containing Linux, Apache, MySQL, and PHP).

Software as a service (SaaS): In this model, an entire business or set of IT applications runs in the cloud. Enterprise consumers outsource the entire underlying technology infrastructure to a SaaS provider and thus have no responsibility or management oversight for SaaS--‐based IT components. Users typically access these applications over the Internet through a thin client interface such as a Web browser. SaaS examples include Gmail from Google, Microsoft “live” offerings, and salesforce.com.

There is no hierarchy in these service offerings; rather, CIOs can choose any or all cloud service offerings that fit their needs.

Cloud Computing

What is cloud computing anyway? Skeptics might say it is nothing but industry hyperbole and visionaries might say it is the future of IT. In reality, both statements are true.

Large organizations are adopting cloud
Cloud computing builds upon current IT trends like data center consolidation and server virtualization. Enterprises will follow a pragmatic path to the cloud by adopting new technologies, transitioning from physical to virtual IT assets, and adapting existing IT best practices to a new dynamic world.

The network acts as the foundation for cloud computing
Cloud computing moves Web based applications to the Internet inexorably tying user connectivity and productivity to networking equipment. Of all networking technologies available, WAN optimization will play a major role in the transition to the cloud. As this happens, WAN optimization must become a virtual service, support mobile users, support innovative applications and protocols, and provide network visibility at a lower level.

Demystifying Cloud ComputingLook at any technology magazine or go to any IT trade show; regardless of where you look, everyone is talking about cloud computing.

ESG believes that a detailed characterization of cloud computing must include three things:

The consumption model: Cloud computing offers a unique way to consume compute, network, and storage resources.

The services model: Cloud computing can be used as a platform for different activities up and down the technology stack.

The deployment model: Cloud computing is not a one size fits all platform. Rather, there are numerous ways to deploy and utilize clouds.