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"The network is the computer," Sun's chief researcher John Gage prophesied in 1984.
In the blooming space of cloud computing, we see an industry trend towards a componetized software ecosystem built on Software as a Service (SaaS), Hardware as a Service (HaaS) and Platform as a Service (PaaS) - all operating in the cloud!. SaaS, HaaS and PaaS are a collection of powerful software forces that to a greater or lesser extent aims at completing the paradigm of cloud computing being drawn with individual offerings largely blurring between them. What they each bring to the table is the power that leverages from enormous economies of scale and operational competencies that Web-based modules deliver. To make an informed decision on which cloud computing facility to employ in your enterprise, let's be informed first.
Cloud computing essentially encapsulates the following three concepts: pay-as-you-go, on-demand and on the Net. It is the computing model of the day, where the use of IT is billed like a utility and hence the term utility computing. Cloud computing is a part of the on-demand model for computing that allows companies to focus on creating true business value rather than delve on setting up and maintaining IT infrastructure to get going.
How do we then, relate cloud computing to SaaS, PaaS and HaaS? As you dig deeper it becomes apparent that SaaS, PaaS and HaaS are different categories of cloud computing. Where SaaS refers to applications in the cloud, PaaS refers to the platforms in the cloud while HaaS refers to the infrastructure in the cloud[1].
The concept of 'Software as a Service' or SaaS, is an application delivery model with vendors hosting Web-based applications on the Internet and consumers consuming them on line. Technologies such as Web services and REST play an integral role in the development of SaaS applications.
The origins of the popular CamelCase term goes back to a white paper published by the Software & Information Industry's eBusiness Division in 2001 titled "Strategic Backgrounder: Software as a Service" [2], in which they discussed, “the delivery, management and payment of software by Application Service Providers (ASPs) as a service rather than a product..” with users 'subscribing' for the use of software rather than purchasing them upfront.
Despite the hype back in the days, the ASP model failed to take off as anticipated by the originators largely due to the unavailability of network and Web being untested grounds for many. Today, tables have clearly turned with Internet access at lightening speeds, increased habitats on the Web and the increased adoption of open standards.
Web 2.0[3] addressed largely the Web-based socializing and consumer-oriented software domain but not SaaS. The list of vertical industries qualifying for SaaS application model include Customer Relationship Management (CRM) systems, Supply Chain Management (SCM) systems, Human Resources Management (HRM) systems, video conferencing, accounting and various others.
SaaS presents a number of licensing and pricing models for the vendors to choose from that includes pay-as-you-go, subscription-based, revenue-based, usage/transaction-based and other. Some even go as far as offering complete services free of charge preferring to monetize with ads only.
The concept of Hardware as a Service' or HaaS refers to, the virtualization of the data center. It appears to be that HaaS provides the real estate support while SaaS provides the application functionality in the journey towards cloud computing supremacy.
With striking similarities to hardware leasing, HaaS is a model in which the vendor manages the lease as opposed to the customer that helps keep service calls to an absolute minimum.
Earlier this year, Apple announced its slightly different flavor of HaaS that promises to improve old hardware with software upgrades an act that was already adopted by Microsoft on Zune devices, Nintendo on wii and Sony on its BlueRay playback on the Playstation.[4]
In the next logical evolution of computing in the cloud comes as an integrated platform to build, test, and deploy custom applications that we called Platform as a Service (PaaS).
The concept of 'Platform as a Service' is a form of cloud computing, that delivers development environments as a service rather than offering full-blown applications. Pioneered by Amazon, Google already has an offer with the Google App engine, where you are able to sign up for a free account to use up to 500MB of persistent storage, CPU and bandwidth for about 5 million page views a month. Sun is on its way with their offering of Platform as a Service in what they called Project Caroline[5].
SaaS is predominantly looked at as an application delivery model, as opposed to the concept of SOA (Service Oriented Architecture)[6] - an architectural strategy weaving together services to create business processes. So, what have they got in common?
On one side, the flexible and scalable pedigree of SOA brings value to SaaS - a loosely coupled, contracted services that empowers SaaS providers more efficiently compete in the marketplace against packaged, on-premise software vendors in terms of price, flexibility and other service quality offerings. As demand for scalability and flexibility mounts, SaaS can only serve in the short term without SOA offerings to enable them optimize the construction and operation of SaaS services for the long run.
On the other side of the equation, increasingly many enterprises expect SaaS be made available for their SOA implementations without getting bogged down in development. As we then see, although the initial impressions of the cloud computing model was all about delivering software, the actual transformation is far more fundamental and deep routed in SOA.
The intersection has been inevitable. The two forms have converged and have already begun to fuse great possibilities for the enterprise.
Is SaaS, cloud computing and PaaS serious enough for the enterprise to build and deploy business applications? Here are the benefits:
Cloud computing seem convincing enough. Buy how about security and privacy?
The concern inevitably raises the question "how much do we need to know about the services we acquire or consume from other sources?To this point I'd say that the companies offering cloud computing services will live and die by their reputations. As cloud computing leaves users to feel that they lose a degree of control over their often-sensitive information - it would be for the cloud operators to convince otherwise.
There are addtional concerns that include concerns of how well the popular pay-as-you-go payment model is defined, as services consumption variables become complex with tiers of service constraints being added.
Infrastructure Providers:
Application Providers:
Platform Providers:
The on-demand model is moving everything from software applications, to processing power, to storage and APIs from desktops and organizational data centers to the cloud. The obstacles are more in the lines of security and privacy. Cloud operators are expected to prove themselves against rival hackers. Despite the concerns, however, the utility-style pay-by-the-drink computing trend will no doubt change the society as profoundly as cheap electricity did centuries ago.
Ayanthi Anandagoda is a Senior Content Specialist at WSO2. ayanthi at wso2 dot com
Really Detailed article , it
Really Detailed article , it help me in learning about SaaS, PaaS and HaaS . i am new to cloud computing but found this article really helpful
Thanks for sharing
Jack
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