cloud computing

                     Cloud Computing  Basics

  What is Cloud Computing?

                           •Cloud computing is 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) [Mell_2009], [Berkely_2009].

•It can be rapidly provisioned and released with minimal management effort.•It provides high level abstraction of computation and storage model.•It has some essential characteristics, service models, and deployment models.

Essential Characteristics:

  •On-Demand Self Service:

•A consumer can unilaterally provision computing capabilities, automatically without requiring human interaction with each service’s provider.

•Heterogeneous Access:

•Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms.

•Resource Pooling:

•The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model.

•Different physical and virtual resources dynamically assigned and reassigned according to consumer demand.

Service:

•Cloud systems automatically control and optimize resources used by leveraging a metering capability at some level of abstraction appropriate to the type of service.

•It will provide analyzable and predictable computing platform.

Service Models:

•Cloud  Software as a Service (SaaS):

•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 such as a web browser (e.g., web-based email).

•The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage,…

•Examples: Caspio, Google Apps, Salesforce, Nivio, Learn.com.

•Cloud Platform as a Service (PaaS):

•The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider.

•The consumer does not manage or control the underlying cloud infrastructure.

• Consumer has control over the deployed applications and possibly application hosting environment configurations.

•Examples: Windows Azure, Google App.

•Cloud Infrastructure as a Service (IaaS):

•The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources.

• 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, deployed applications, and possibly limited control of select networking components (e.g., host firewalls).

•Examples: Amazon EC2, GoGrid, iland, Rackspace Cloud Servers, ReliaCloud.

Diagrammatic  Representation:

Deployment Models:
 lPrivate Cloud:

-The cloud is operated solely for an organization. It may be managed by the organization or a third party and may exist on premise or off premise.

lCommunity 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 

or off premise

lPublic Cloud:

-The cloud infrastructure is made available to the general public or a large industry group and it is owned by an organization selling cloud services.

lHybrid cloud:

-The cloud infrastructure is a composition of 

  two or more    clouds (

private, community, or 

:Advantages of Cloud Computing  

   lCloud computing do not need high quality equipment for user, and it is very easy to use.lProvides dependable and secure data storage center.lReduce run time and response time.lCloud is a large resource pool that you can buy on-demand service.lScale of cloud can extend dynamically providing nearly infinite possibility for users to use internet..(public