The world

Confused from all the talk about cloud computing? Feel you need a little more understanding to be matters? This is a sequel to post its introductory post I described the difference between PaaS, SaaS and IaaS. Cloud applications are different and strange. In some cases, entire business applications (such as NetSuite) and Salesforce, sometimes the service is targeted (such as Geo Location). There are public cloud (Amazon), collaborative (eg - government) and private clouds (intra-enterprise), there are infrastructure providers (Amazon) and hosting providers are not necessarily cloud providers. What makes an application to the cloud application or service to a cloud service? The answer of course is not complete and there are numerous different variations of suppliers and services. Still, I collected the ten characteristics of the major cloud applications and services.
First, some definitions I'd use this post: cloud services provider - Amazon, Salesforce, Microsoft or Google. Hosting company which performs and provides opportunity me with infrastructure and services which will build my cloud app. Cloud service - infrastructure, such as Amazon's EC2 or Microsoft Azure with their help I will build my app. Cloud app - the ultimate end-user application that I am developing, using in cloud services provided opportunity by cloud service providers. 1.Hosting or Off-Premises - as opposed to services On-Premises managed the organization's opportunity server farm, most cloud applications will be installed on the computers of the cloud service provider and across organizational boundaries. This has two important implications: opportunity one - the end-user information service is delivered over the Internet (and not the organization's internal network or VPN). Second - information is stored and processed outside the corporate firewall. The communication between the service crosses the boundaries and limits of the physical security of the organization. 2. Elastic grow and shrink as needed. The principle opportunity that goes hand-in-hand with cloud services is the principle of On-Demand: Use as needed. For example: We sales and we have a Sale crazy? We expect double traffic than usual next week? Hosting Providers will allow us to double the number of servers opportunity in use within minutes and stop using after a week. auction sites online to the US, where a significant part of annual sales takes place during the Christmas, is the difference between holding Hardware triple double every year (who knows how much traffic will be at the end of the year? - Missing sales is intolerable) to use it for one month per year [1]. 3. Virtualization - most cloud applications are not installed directly on the operating system. In order to provide highly elastic, ie - to increase and decrease the volume faster service, provide The service must be able to allocate more machines (hardware) to the customer a very short time. If all demand for more power calculation / storage service had to be a man Operations that perform physical installation of the server - the response will be quite slow.
The world's IaaS solution is to install an operating system (Host OS) virtualization software on it (hypervisor). The hypervisor opportunity will run (on demand) Operating system (one or more), called Guest OS, which will be installed in the customer's image. The image is a copy of an operating system that is installed with your software and configured accordingly opportunity - ready to go. In different environments (for example, Amazon) service provider offers a selection of Images willing operating systems and arrangements for licenses with the manufacturer (Microsoft) to facilitate the process user. Just ask for "a large machine with Windows Server 2008 64-bit" and in half a minute you have a server online ready to go. On the other supplier, In order to provide the above service, he simply selects an unused physical server opportunity (or had just returned to the pool by another client), closes the process of one and Guest OS Guest OS running another on the basis of the image you provided it (often save network , Amazon S3 uses - its decentralized storage service also save the Images). do not have physical access to your computer, do not need the involvement of an Operations and do not even have Restart. opportunity Great! virtualization opportunity field has 4 key players: VMware (acquired by EMC ) - commercial, and established a rich set of capabilities. [Update 2014: Surprisingly, it is still the most common virtualization solution]. KVM (short-Kernel-Based Virtual Machine) - free solution, and popular, Linux. XEN - originally free, but commercial versions of common applications, such as Citrix XenServer. Oracle's VirtualBox (source: the Sun), similar in many ways to VMWare. Wi virtualization called Full Virtualization (eg VMWare) - this is common approach opportunity and has good compatibility for legacy systems, and another approach called paravirtualization (providing layer is more like the original material and labor-saving device which Guest OS) - which to use it is necessary to support specific operating system. A common example of paravirtualization Nowadays it XEN. Another very common approach recently, her huge efforts computing (such as Google, or Netflix) is an approach containers. I wrote a post that deals with virtualization. 4. Billing according to actual use - as mentioned in point 2, the aim is to charge based on actual use. Possibly because the same computer running several different customer service (due mainly virtualization), all cloud service provider has its own method based on the amount opportunity of use charge: The amount of CPU usage, disk, network, etc. [2]. Sometimes supplier encourages the use of dead hours by providing lower rates, so it can take advantage of the hardware is superior in his possession. Mostly opportunity cloud provider payment possible with a credit card, making the accession simple. 5. cheap hardware (Commodity hardware) of the major reasons to use cloud computing is cost reduction. In most cloud environments we can not know on what hardware just run our application in practice, opportunity and most of our application form Scalabale be written in advance so that it can grow if we add more servers (hardware). You can take advantage of this fact and use a fairly inexpensive hardware - CPU Cycles has a maximum power consumption unit. Power consumption dictates to