Cloud computing
Cloud computing as a model for enabling convenient , on-demand network access to a shared pool of configurable computing resources ( e.g networks , servers , storage , applications and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.
Few essential characteristics for cloud are:
1. Board Network Access—heterogeneous thin and thick client platforms
2. On-demand self service – lesser human interaction
3. Resource pooling –Pool of resources for multiple consumers using a multi tenent model
4. Fast scaling – or Rapid elasticity
5. Measured service – resources usage can be monitored , controlled and reported providing transparency for both the provider and consumer of the utilized service.
Cloud deployment Models
Private cloud – The cloud infrastructure is operated solely for an organization . It may be managed by organization or a third party and may exit on premise of off premise,
Community cloud – the cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns. It may be managed by the organizations or a third party and may exist on premise of off premise.
Public Cloud – The cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.
Hybrid Cloud – The cloud infrastructure is a composition of two or more clouds( private , community or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability .
The Cloud Service models
1. Cloud software as a service (SaaS) -- The consumer does not manage or control the underlying cloud infrastructure including network , servers , operating systems , Storage or even individual application capabilities .This is like on demand applications.
2. Cloud Platform as a Service ( PaaS) – The Capability provided to the consumers is to deploye onto the cloud infrastructure consumer – created or acquired applications created using programming languages and tools supported by the provider.
3. Cloud Infrastructure as a Service ( IaaS) – 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.
