【正文】 interdependent IT trends: IT Efficiency — Minimize costs where panies are converting their IT costs from capital expenses to operating expenses through technologies such as virtualization. Cloud puting begins as a way to improve infrastructure resource deployment and utilization, but fully exploiting this infrastructure eventually leads to a new application development model. Business Agility — Maximize return using IT as a petitive weapon through rapid time to market, integrated application stacks, instant machine image deployment, and petascale parallel programming. Cloud puting is embraced as a critical way to revolutionize time to service. But inevitably these services must be built on equally innovative rapiddeploymentinfrastructure models. To be sure, these trends have existed in the IT industry for years. However, the recent emergence of massive work bandwidth and virtualization technologies has enabled this transformation to a new servicesoriented infrastructure. Cloud puting enables IT anizations to increase hardware utilization rates dramatically, and to scale up to massive capacities in an instant — without constantly having to invest in new infrastructure, train new personnel, or license new software. It also creates new opportunities to build a better breed of work services, in less time, for less money. IT Efficiency on a Whole New Scale Cloud puting is all about efficiency. It provides a way to deploy and access everything from single systems to huge amounts of IT resources — on demand, in real time, at an affordable cost. It makes highperformance pute and highcapacity storage available to anyone with a credit card. And since the best cloud strategies build on concepts and tools that developers already know, clouds also have the potential to redefine the relationship between information technology and the developers and business units that depend on it. Reduce capital expenditures — Cloud puting makes it possible for panies to convert IT costs from capital expense to operating expense through technologies such as virtualization. Cut the cost of running a datacenter — Cloud puting improves infrastructure utilization 3 rates and streamlines resource management. For example, clouds allow for selfservice provisioning through APIs, bringing a higher level of automation to the datacenter and reducing management costs. Eliminate over provisioning — Cloud puting provides scaling on demand, which, when bined with utility pricing, removes the need to overprovision to meet demand. With cloud puting, panies can scale up to massive capacities in an instant. For those who think cloud puting is just fluff, take a closer look at the cloud offerings that are already available. Major Inter providers , Google, and others are leveraging their infrastructure investments and “sharing” their largescale economics. Already the bandwidth used by Amazon Web Services (AWS) exceeds that associated with their core etailing services. Forwardlooking enterprises of all types — from Web startups to global enterprises — are embracing cloud puting to reduce infrastructure costs. Faster, More Flexible Programming Cloud puting isn’t only about hardware — it’s also a programming revolution. Agile, easytoaccess, lightweight Web protocols — coupled with pervasive horizontally scaled architecture — can accelerate development cycles and time to market with new applications and services. New business functions are now just a script away. Accelerated cycles — The cloud puting model provides a faster, more efficient way to develop the new generation of applications and services. Faster development and testing cycles means businesses can acplish in hours what used to take days, weeks, or months. Increase agility — Cloud puting acmodates change like no other model. For example, Animoto Productions, makers of a mashup tool that creates video from images and music, used cloud puting to scale up from 50 servers to 3,500 in just three days. Cloud puting can also provide a wider selection of more lightweight and agile development tools, simplifying and speeding up the development process. The immediate impact will be unprecedented flexibility in service creation and accelerated development cycles. But at the same time, development flexibility could bee constrained by APIs if they’re not truly open. Cloud puting can usher in a new era of productivity for developers if they build on platforms that are designed to be federated rather than centralized. But there’s a major shift underway in programming culture and the languages that will be used in 4 clouds. Today, the integrated, optimized, opensource Apache, MySQL, PHP/Perl/Python (AMP) stack is the preferred platform for building and deploying new Web applications and services. Cloud puting will be the catalyst for the adoption of an even newer stack of more lightweight, agile tools such as ligd, an opensource Web server。 Hadoop, the free Java software framework that supports dataintensive distributed applications。 they also define a new application development model. And within each layer of 9 abstraction there are myriad business opportunities for defining services that can be offered on a payperuse basis. Software as a Service (SaaS) SaaS is at the highest layer and features a plete application offered as a service, on demand, via multitenancy — meaning a single instance of the software runs on the provider’s infrastructure and serves multiple client anizations. The most widely known example of SaaS is , but there are now many others, including the Google Apps offering of basic business services such as . Of course, ’