cloud computing – A perspective

cc1Cloud computing is the delivery of computing as a service rather than a product, whereby shared resources, software, and information are provided to computers and other devices as a utility (like the electricity grid) over a network (typically the Internet )

Cloud computing entrusts services (typically centralized) with a user’s data, software and computation on a published application programming interface (API) over a network. It has considerable overlap with software as a service (SaaS).

End users access cloud based applications through a web browser or a light weight desktop or mobile app while the business software and data are stored on servers at a remote location. Cloud application providers strive to give the same or better service and performance than if the software programs were installed locally on end-user computers.

At the foundation of cloud computing is the broader concept of infrastructure convergence (or Converged Infrastructure) and shared services. This type of data centre environment allows enterprises to get their applications up and running faster, with easier manageability and less maintenance, and enables IT to more rapidly adjust IT resources (such as servers, storage, and networking) to meet fluctuating and unpredictable business demand.

Cloud computing providers offer their services according to three fundamental models: Infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS) where IaaS is the most basic and each higher model abstracts from the details of the lower models.

Platform as a Service (PaaS) is a way to rent hardware, operating systems, storage and network capacity over the Internet. The service delivery model allows the customer to rent virtualized servers and associated services for running existing applications or developing and testing new ones.

Platform as a Service (PaaS) is an outgrowth of Software as a Service (SaaS), a software distribution model in which hosted software applications are made available to customers over the Internet. PaaS has several advantages for developers. With PaaS, operating system features can be changed and upgraded frequently. Geographically distributed development teams can work together on software development projects. Services can be obtained from diverse sources that cross international boundaries. Initial and ongoing costs can be reduced by the use of infrastructure services from a single vendor rather than maintaining multiple hardware facilities that often perform duplicate functions or suffer from incompatibility problems. Overall expenses can also be minimized by unification of programming development efforts.

On the downside, PaaS involves some risk of “lock-in” if offerings require proprietary service interfaces or development languages. Another potential pitfall is that the flexibility of offerings may not meet the needs of some users whose requirements rapidly evolve.

 Infrastructure as a Service

In this most basic cloud service model, cloud providers offer computers – as physical or more often as virtual machines –, raw (block) storage, firewalls, load balancers, and networks. IaaS providers supply these resources on demand from their large pools installed in data centers. Local area networks including IP addresses are part of the offer. For the wide area connectivity, the Internet can be used or – in carrier clouds – dedicated virtual private networks can be configured.

To deploy their applications, cloud users then install operating system images on the machines as well as their application software. In this model, it is the cloud user who is responsible for patching and maintaining the operating systems and application software. Cloud providers typically bill IaaS services on a utility computing basis, that is, cost will reflect the amount of resources allocated and consumed.

Platform as a Service
(PaaS)

In the PaaS model, cloud providers deliver a computing platform and/or solution stack typically including operating system, programming language execution environment, database, and web server. Application developers can develop and run their software solutions on a cloud platform without the cost and complexity of buying and managing the underlying hardware and software layers. With some PaaS offers, the underlying compute and storage resources scale automatically to match application demand such that the cloud user does not have to allocate resources manually.

 Software as a Service (SaaS)

In this model, cloud providers install and operate application software in the cloud and cloud users access the software from cloud clients. The cloud users do not manage the cloud infrastructure and platform on which the application is running. This eliminates the need to install and run the application on the cloud user’s own computers simplifying maintenance and support. What makes a cloud application different from other applications is its elasticity. This can be achieved by cloning tasks onto multiple virtual machines at run-time to meet the changing work demand. Load balancers distribute the work over the set of virtual machines. This process is
transparent to the cloud user who sees only a single access point. To accomodate a large number of cloud users, cloud applications can be multitenant, that is, any machine serves more than one cloud user organization.
It is common to refer to special types of cloud based application software with a similar naming convention: desktop as a service, business process as a service, Test Environment as a Service, communication as a service.

The pricing model for SaaS applications is typically a monthly or yearly flat fee per user.

Essential Characteristics:

On-demand self-service. A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service provider.
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, tablets, laptops, and workstations).
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 (e.g., country, state, or datacenter). Examples of resources include storage, processing, memory, and network bandwidth.
Rapid elasticity. Capabilities can be elastically provisioned and released, in some cases automatically, to scale rapidly outward and inward commensurate with demand. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be appropriated in any quantity at any time.
Measured service. Cloud systems automatically control and optimize resource use by leveraging a metering capability1 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.

Service Models:

Cloud clients

Users access cloud computing using networked client devices, such as desktop computers, laptops, tablets and smartphones. Some of these devices – cloud clients – rely on cloud computing for all or a majority of their applications so as to be essentially useless without it. Examples are thin clients and the browser-based Chrome-book. Many cloud applications do not require specific software on the client and instead use a web browser to interact with the cloud application. With Ajax and HTML5 these Web user interfaces can achieve a similar or even better look and feel as native applications. Some cloud applications, however, support specific client
software dedicated to these applications (e.g., virtual desktop clients and most email clients). Some legacy applications (line of business applications that until now have been prevalent in thin client Windows computing) are delivered via a screen-sharing technology.

 Deployment models

Cloud computing types Public cloud Applications, storage, and other resources are made available to the general public by a service provider. Public cloud services may be free or offered on a pay-per-usage model. There are limited service providers like Microsoft, Google etc owns all Infrastructure at their Data Center and the access will be through Internet mode only. No direct connectivity proposed in Public Cloud Architecture.

Community cloud
Community cloud shares infrastructure between several organizations from a specific community with common concerns (security, compliance, jurisdiction, etc.), whether managed internally or by a third-party and hosted internally or externally. The costs are spread over fewer users than a public cloud (but more than a private cloud), so only some of the cost savings potential of cloud computing are realized.

 Hybrid cloud
Hybrid cloud is a composition of two or more clouds (private, community or public)
that remain unique entities but are bound together, offering the benefits of multiple deployment models.

 Private cloud
Private cloud is cloud infrastructure operated solely for a single organization, whether managed internally or by a third-party and hosted internally or externally.

They have attracted criticism because users “still have to buy, build, and manage them” and thus do not benefit from less hands-on management, essentially “[lacking] the economic model that makes cloud computing such an intriguing concept”.

Private cloud is a computing model that uses resources which are dedicated to your organization. A private cloud shares many of the characteristics of public cloud computing including resource pooling, self-service, elasticity and pay-by-use delivered in a standardized manner with the additional control and customization available from dedicated resources.
While virtualization is an important technological component of private cloud, the key differentiators is the continued abstraction of computing resources from infrastructure and the machines (virtual or otherwise) used to deliver those resources.
Only by delivering this abstraction can customers achieve the benefits of private cloud – including improved agility and responsiveness, reduced TCO, and increased business alignment and focus. Most importantly, a private cloud promises to exceed the cost effectiveness of a virtualized infrastructure through higher workload density and greater resource utilization.

With a private cloud, you get many of the benefits of public cloud computing—including self-service, scalability, and elasticity—with the additional control and customization available from dedicated resources.
Two models for cloud services can be delivered in a private cloud:
Infrastructure as a Service (IaaS) and Platform as a Service (PaaS). With IaaS, you can use infrastructure resources (compute, network, and storage) as a service, while PaaS provides a complete application platform as a service.

 Architecture

Cloud architecture, the systems architecture of the software systems involved in the delivery of cloud computing, typically involves multiple cloud components communicating with each other over a loose coupling mechanism such as a messaging queue.
Elastic provision implies intelligence in the use of tight or loose coupling as applied to mechanisms such as these and others.

 The Inter-cloud

The Inter-cloud is an interconnected global “cloud of clouds” and an extension of the Internet “network of networks” on which it is based.

 Cloud engineering
Cloud engineering is the application of engineering disciplines to cloud computing. It brings a systematic approach to the high level concerns of commercialization, standardization, and governance in conceiving, developing, operating and maintaining cloud computing systems. It is a multidisciplinary method encompassing contributions from diverse areas such as systems, software, web, performance, information, security, platform, risk, and quality engineering.

Private cloud solutions are from Microsoft and VMware

.
Microsoft private cloud solutions are licensed on a per processor basis, so customers get the cloud computing benefits of scale with unlimited virtualization and lower costs – consistently and predictably over time.

VMware private cloud solutions are licensed by either the number of virtual machines or the virtual memory allocated to those virtual machines – charging you more as you grow. This difference in approach means that with Microsoft your private cloud ROI increases as your private cloud workload density increases. With VMware,  cost grows, as  workload density does. The reason for this significant cost difference is VMware’s per-VM licensing for private cloud products like VMware vCenter Operations Management Suite   and drives this cost differential.

Economics has always been a powerful force in driving industry transformations and as more and more customers evaluate cloud computing investments that will significantly affect ROI, now is the time to provide the information they need to make informed decisions, for today and tomorrow.

Microsoft Private Cloud – Unlimited Virtualization Rights Microsoft private cloud solutions are built using Windows Server with Hyper-V and System Center – the combination of which provides enterprise class virtualization, end-to-end service management and deep insight into applications so users can focus more attention on delivering business value.
Microsoft private cloud solutions are delivered through  wide ecosystem of partners and are offered as custom, pre-configured, or hosted offerings – so, no matter  unique business need; there is a Microsoft private cloud solution for it.
Microsoft private cloud solution is licensed through the Microsoft Enrollment for Core Infrastructure1 (ECI) licensing program. ECI is a Microsoft Enterprise Agreement (EA) enrollment, available in two editions (Datacenter and Standard), that allows a
simple and flexible per processor licensing option. Its approach is focused on delivering the benefits of scale – through unlimited virtualization rights and significantly simplified licensing for Windows Server and System Center.

VMware
Private Cloud – Per-VM Licensing In 2011, VMware announced the latest version of its virtualization platform, vSphere 5.0, along with updated versions of surrounding technologies;
vCenter Site Recovery Manager,
vShield Security and vCloud Director.

These products collectively are referred to as Cloud Infrastructure Suite. VMware has also released several management products like vCenter Operations Management Suite and vFabric Application Performance Manager (APM) to provide capabilities like monitoring, application performance management, and configuration
management. To build a comparable private cloud solution using VMware technologies,  require components from VMware Cloud Infrastructure suite, vCenter Operations Management Suite and vFabric APM as a private cloud solution requires capabilities like monitoring, configuration, automation, orchestration and security in addition to the virtualization platform.
Unlike Microsoft ECI Datacenter, VMware Cloud Infrastructure Suite, vCenter Operations Management Suite, and vFabric APM cannot be licensed as a single SKU, but have to be licensed separately for individual products. Moreover, VMware private cloud products follow a combination of three different licensing schemes-   vSphere 5.0 is licensed on a per processor basis with virtual RAM entitlements vCenter is licensed on a per-instance basis Cloud Infrastructure products – vCloud Director, vCenter Site Recovery Manager, and vShield are licensed on a per-VM basis3   vCenter
Operations Management Suite and vFabric APM are licensed on a per-VM
basis5
Microsoft® offers solutions that deliver IaaS and PaaS for both private and public cloud deployments. This  focuses on Microsoft solutions for IaaS and provides an overview of Microsoft Hyper-V™ Cloud, a set of programs and initiatives to help customers and partners accelerate deployment of IaaS

Organizations can build a private cloud today with Windows Server® 2008 R2, Microsoft Hyper-V, and Microsoft System Center.
The foundation is built on the Windows Server platform with the Windows Server Active Directory® identity framework, Hyper-V virtualization capability, and System Center end-to-end service management capabilities.
The new System Center Virtual Machine Manager Self-Service Portal 2.0 simplifies the pooling, allocation, provisioning, and usage tracking of datacenter resources, so that your business units can consume Infrastructure as a Service.

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