Nowadays companies go away of keeping entire IT infrastructure “on the spot”. It has many advantages like reduction of costs by hiring less IT engineers or buying less needed IT stuff (switches, routers servers etc) and no worries about IT problems hardware or software. In this article I’m going to look closer the Clouds from the end consumer point of view and what types of services can be delivered via a Cloud.
What Cloud Computing is?
In cloud computing, a cloud is a collection of IT resources, including hardware and software resources that is deployed either in a single data center, or across multiple geographically-dispersed data centers that are connected over a network. A cloud infrastructure is built, operated, and managed by a cloud service provider. The cloud computing model enables consumers to hire IT resources as a service from a provider. A cloud service is a combination of hardware and software resources that are offered for consumption by a provider. The cloud infrastructure contains IT resource pools, from which resources are provisioned to consumers as services over a network, such as the Internet or an intranet. Resources return to the pool when released by consumers. Consumers simply hire IT resources as services from the cloud without the risks and costs associated with owning the resources. Cloud services are accessed from different types of client devices over wired and wireless network connections. Consumers pay only for the services that they use, either based on a subscription or based on resource consumption. When organizations use cloud services, their IT infrastructure management tasks are reduced to managing only those resources that are required to access the cloud services. The cloud infrastructure is managed by the provider, and tasks such as software updates and renewals are also handled by the provider.
Cloud Service Models
Cloud Service Model can be classified into primary three models :
Infrastructure as a Service (IaaS)
Platform as a Service (PaaS)
Software as a Service (SaaS)
Infrastructure as a Service
The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, and deployed applications; and possibly limited control of select networking components (for example, host firewalls).IaaS pricing may be subscription-based or based on resource usage. The provider pools the underlying IT resources and they are typically shared by multiple consumers through a multi- tenant model. IaaS can even be implemented internally by an organization, with internal IT managing the resources and services.
Platform as a Service
The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment. In the PaaS model, a cloud service includes compute, storage, and network resources along with platform software. Platform software includes software such as OS, database, programming frameworks, middleware, and tools to develop, test, deploy, and manage applications. Most PaaS offerings support multiple operating systems and programming frameworks for application development and deployment. PaaS usage fees are typically calculated based on factors, such as the number of consumers, the types of consumers (developer, tester, and so on), the time for which the platform is in use, and the compute, storage, or network resources consumed by the platform.
Software as a Service
The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser (for example, web-based email), or a program interface. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings. In the SaaS model, a provider offers a cloud-hosted application to multiple consumers as a service. The consumers do not own or manage any aspect of the cloud infrastructure. In SaaS, a given version of an application, with a specific configuration (hardware and software) typically provides service to multiple consumers by partitioning their individual sessions and data. SaaS applications execute in the cloud and usually do not need installation on end-point devices. This enables a consumer to access the application on demand from any location and use it through a web browser on a variety of end-point devices. Some SaaS applications may require a client interface to be locally installed on an end-point device. Customer Relationship Management (CRM), email, Enterprise Resource Planning (ERP), and office suites are examples of applications delivered through SaaS.
During writing this article I used EMC and NIST (National Institute of Standards and technology ) publications. All pictures originate from EMC.