CLOUD COMPUTING
Cloud computing is a model for enabling ubiquitous, convenient, on-demand access to a shared pool of configurable computing resources. Cloud computing and storage solutions provide users and enterprises with various capabilities to store and process their data in third-party data centers.[3] It relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over a network.[4] At the foundation of cloud computing is the broader concept of converged infrastructure andshared services.
Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the effectiveness of the shared resources. Cloud resources are usually not only shared by multiple users but are also dynamically reallocated per demand. This can work for allocating resources to users. For example, a cloud computer facility that serves European users during European business hours with a specific application (e.g., email) may reallocate the same resources to serve North American users during North America's business hours with a different application (e.g., a web server). This approach helps maximize the use of computing power while reducing the overall cost of resources by using less power, air conditioning, rack space, etc. to maintain the system. With cloud computing, multiple users can access a single server to retrieve and update their data without purchasing licenses for different applications
Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the effectiveness of the shared resources. Cloud resources are usually not only shared by multiple users but are also dynamically reallocated per demand. This can work for allocating resources to users. For example, a cloud computer facility that serves European users during European business hours with a specific application (e.g., email) may reallocate the same resources to serve North American users during North America's business hours with a different application (e.g., a web server). This approach helps maximize the use of computing power while reducing the overall cost of resources by using less power, air conditioning, rack space, etc. to maintain the system. With cloud computing, multiple users can access a single server to retrieve and update their data without purchasing licenses for different applications
CLOUD
COMPUTNG SERVICES :-
A. Infrastructure-as-a-Service
The Infrastructure as a Service is a provision
model in which an organization outsourcers the equipment used to support
operations, including storage, hardware, servers and networking components. The service provider owns the equipment and is
responsible forhousing,
running and maintaining it. The client typically pays on a per-use basis.
Characteristics
and components of IaaS include:
1.
Utility computing service and billing model.
2.
Automation of administrative tasks.
3.
Dynamic scaling.
4.
Desktop virtualization.
5.
Policy-based services.
6.
Internet connective
Infrastructure-as-a-Service like
Amazon Web Services provides virtual server instances with unique IP addresses
and blocks of storage on demand. Customers use the provider's application program
interface (API) to start, stop, access and configure their virtual servers and
storage.
B. Plateform-As-A-Service
Platform as a Service (PaaS) is a way to rent
hardware, operating systems, storage and network capacity over the
Internet. The service delivery model allows the
customer to rent virtualized servers and associated services for running
existing applications or developing and testing new ones. Platform as a Service
(PaaS) is an outgrowth of Software as a Service (SaaS), a software distribution
model in which hosted software applications are made available to customers
over the Internet. PaaS has several advantages for developers. With PaaS,
operating system features can be changed and upgraded frequently.
Geographically distributed development teams can work together on software
development projects. Services can be obtained from diverse sources that cross
international boundaries. Initial and ongoing costs can be reduced by the use
of infrastructure services from a single vendor rather than maintaining
multiple hardware facilities that often perform
duplicate functions or suffer from incompatibility problems.
C. Software-As-A-Service
No Software as a service
sometimes referred to as "software on demand," is software that is
deployed over the internet and/or is deployed to run behind a firewall on a
local area network or personal computer. With SaaS, a provider licenses an
application to customers either as a service on demand, through a subscription,
in a "pay-as-you-go" model, or at no charge. This approach to
application delivery is part of the utility computing model where all of the
technology is in the "cloud" accessed over the Internet as a service.
SaaS was initially widely deployed for sales force automation and Customer Relationship
Management (CRM).
CLOUD COMPUTNG MODELS :-
A. Public Cloud
A
public cloud is one based on the standard cloud computing model, in which a
service provider makes resources, such as applications and storage, available
to the general public over the Internet. Public cloud services may be free or
offered on a pay-per-usage model.
The
main benefits of using a public cloud service are:
1.
Easy and inexpensive set-up because hardware, application and bandwidth costs
are covered by the provider.
Scalability
to meet needs.
2.
No wasted resources because you pay for what you use.
3. The term "public
cloud" arose to differentiate between the standard model and the private
cloud, which is a proprietary network or data center that uses cloud computing
technologies, such as virtualization. A private cloud is managed by the organization
it serves.
B. Community Cloud
Private cloud (also called
internal cloud or corporate cloud) is a marketing term for a proprietary
computing architecture that provides hosted services to a limited number of
people behind a firewall. Advances in virtualization and distributed computing
have allowed corporate network and datacenter administrators to effectively
become service providers that meet the needs of their "customers"
within the corporation. Marketing media that uses the words "private cloud"
is designed to appeal to an organization that needs or wants more control over
their data than they can get by using a third-party hosted service such as
Amazon's Elastic Compute Cloud (EC2) or Simple Storage Service (S3).
C. Hybrid Cloud
A hybrid cloud is a Cloud Computing environment
in which an organization provides and manages some resources in-house and has
others provided externally. For example, an organization might use a public
cloud service, such as Amazon Simple Storage Service (Amazon S3) for archived
data but continue to maintain in-house storage for operational customer data.
Ideally, the hybrid approach allows a business to take advantage of the
scalability and cost-effectiveness that a public cloud computing environment
offers without exposing mission-critical applications and data to third-party
vulnerabilities.
D. Private Cloud
A community cloud may be
established where several organizations have similar requirements and seek to
share infrastructure so as to realize some of the benefits of cloud computing.
With the costs spread over fewer users than apublic cloud (but more than a
single tenant) this option is more expensive but may offer a higher level of
privacy, security and/or policy compliance. Examples of community cloud include
Google's "Gov Cloud".
