cloud computing

what #

The concept of cloud computing has existed for 50 years, since the beginning of the Internet.It was devised the idea of time-sharing in computers as a utility in 1957.Since then, the concept’s name has undergone several changes: from service bureau, to application service provider, to the Internet as a service, to cloud computing, and to software-defined datacenters, with each name having different nuances. However, the core concept is the same: providing IT services based on the Internet (the cloud).

different types #

Cloud Computing architecture has three models: infrastructure as a service (IaaS),platform as a service (PaaS) and software as a service (SaaS).

• Infrastucture as a Service (IaaS) - It virtualizes the data center’s computing power, storage, loadbalancers , templatized runtime engines and network connectivity. Users can scale these computing resources up and down on demand dynamically and/or based on a given set of rules upon which action would be taken by the cloud engine.

• Platform as a Service (PaaS) - It provides a development platform with services to assist application design, implementation, testing, deploy­ment, monitoring, and hosting in the cloud. It requires no software download( although not entirely true may need to download IDE to be able to work with Cloud runtimes) or installation and supports geographi­cally distributed collaborative work.

• Software as a Service(SaaS) - It includes both software components (for application developers) and applications (for users). An SaaS application is often a service-oriented program so that it is easy to integrate with other SaaS applications.Software that performs various tasks is not on the client machine. Instead, third-party service providers host and manage the software services in the cloud.

key attributes #

• Agility
• Multi tenancy
• Scalibility and Elasticity
• Monitoring & Performance Optimization Enablement
• Security
• Maintenancibility

deployment models #

• private cloud - cloud infrastructure operated solely for a single organization, whether managed internally or by a third-party, and hosted either internally or externally. Most Organizations already use virtualization internally to provision environments as it has minimizes their need to go through hardware procurement lifecycle of buy , build and manage hardware systems in their datacenter. Virtualization is indeed some form of private cloud , or you can host applications in cloud providers restricting to only your network.

• public cloud - cloud infrastructure that renders services over a network that is open for public use.Technically there may be little or no difference between public and private cloud architecture, however, security consideration may be substantially different for services (applications, storage, and other resources) that are made available by a service provider for a public audience and when communication is effected over a non-trusted network.

• hybrid cloud - cloud infrastructure thats a composition of two or more clouds (private and/or public) which are two different entities but are bound together, offering the benefits of multiple deployment models. Hybrid cloud can also mean the ability to connect collocation, managed and/or dedicated services with cloud resources. It could also be public clouds in more than one cloud providers.

cloud providers #