Cloud Computing: Cloud Computing Deployment Models

Cloud computing is innovated model which delivers convenient and on-demand computing services over internet to requested end users. Cloud computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the data centers that provide the services such as Software as a Service (SaaS), PaaS (Platform as a Service) and IaaS (Infrastructure as a Service). There are three Cloud models which companies can choose from, which are public Cloud computing, private Cloud computing and hybrid Cloud computing.

1. Public Cloud:

The public cloud is the most commonly referenced regarding the topic of cloud computing, where the infrastructure and applications are owned by the organization selling cloud services. In simple terms, a public cloud is characterised as being available to clients from a third party service provider through the internet and applications from different users are shared on the provider’s cloud servers, storage systems, and networks. For example, Gmail, Amazon and Hotmail typify the public cloud. Public clouds are most often hosted away from customer premises, and they try to reduce customer risk and cost by substituting their enterprise infrastructure. Applications which are required for temporary purpose or for short duration are the best suitable for deployment in a public cloud because it avoids the need to purchase additional equipment to solve a temporary need.

2. Private Cloud:

Private cloud is typically hosted on customer premises. With proprietary computing architecture, it provides hosted services to authorized users behind a company firewall. Thus company has control over resources, data, security and QoS (Quality of service). The company owns the infrastructure and controls how applications are deployed in an organization data center or also at a collocation facility. Company’s own IT department or cloud service provider can build and manage private clouds where a company can install, configure, and operate the infrastructure as per its requirement and demand and use them for critical and other secured systems deployment. But if the company chooses, it can also be managed offsite, either as a hosted or managed cloud, by a service provider. A private cloud will not benefit large scale businesses such as large banks, government departments, and many other large enterprises, which are big enough to run their own networks and high-grade IT Infrastructure and are able to adopt their own shared service business models for the delivery of IT to business units as the investment in high-grade IT Infrastructure (power, speed or storage) is often beyond a small business.

3. Hybrid Cloud:

Hybrid cloud is a cloud computing infrastructure composed of multiple clouds (private and public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability. In hybrid cloud, companies and individuals can obtain degrees of fault tolerance combined with locally immediate usability without internet connectivity. It is the ideal combination that requires on premises resources and off site (remote) server based cloud infrastructure. Hybrid clouds do not have the flexibility, security and certainty of in-house applications. Users prefer to use their data center tools to manage hybrid cloud environments to create applications, or move existing applications between the clouds in a hybrid cloud environment, without having to change anything serious like networking, security policies, operational processes or management/monitoring tools. This creates a problem because, due to issues around interoperability, mobility and differing APIs, tools, policies and processes, hybrid clouds generally increase complexity.