What is cloud computing?
Cloud computing in its simplest form can be
defined as an ability that allows users to access
computing resources (think storage , servers )
and/or applications – anything ranging from ERP
applications, email, accounting software (Tax
preparation) - from anywhere on the internet.
Key characteristics of cloud computing architecture are
-Virtualization of infrastructure and services
-Elasticity (increase or decrease of computing resources on demand)
-Availability and reliability.
-Flexibility and Agility
-Pay as you grow (aka pay for what you use)
What are various Cloud Service Models?
Cloud Service providers offer services from
complete infrastructures services to
specialized business processes.
Across all cloud service models the key
common characteristic is that users of the
cloud service will only be aware of the
service and its use. They have no need to
understand details or manage the
software or implementation of that service.
The Cloud computing abstracts complexity and virtualizes all components involved in the
service from the end user/organization.
Business Process as a Service - Business Process as a Service (BPaaS) is when an external party is
assigned the responsibility of managing a business process, for instance letting a third party (ex:
Equifax) take care of credit check on customers for you. All we have to do is call the web
service using API’s and gets the response back as “good or bad” .The services are available over
network and the organization only pays as it uses them and not having to build their own
system or services for doing credit checks.
Software as a Service - Software as a Service (SaaS) is the entire application software (ex:
Salesforce.com CRM) hosted by a provider in remote datacenter and made accessible to end
users over a WAN. The service can be deployed quickly and users only pay as they go model.
Upfront capital and development expenditure is not incurred and user organizations do not
manage and maintain the host application.
Platform as a Service - Platform as a Service (PaaS), provides a development environment
where users can deploy, build and test their applications. It includes both hardware and
software components needed to create a platform for development. Organization consuming
this service model can do so without having to worry about the cost, complexity and time
constraints to create such a platform for development and testing.
Infrastructure as a Service - Infrastructure as a Service (IaaS) is the most basic service model
that provides hardware such as servers, storage. With IaaS, a consuming organization can run
all applications without having to set-up and manage their own in-house data centers. This
service model is actually the most matured offering today and a common example will be
Amazon’s Elastic Compute Cloud,( EC2) an IaaS—where organizations can rent servers, storage
and run their own applications.
What are various Cloud Computing Deployment Models?
Just as there are various Cloud service models, we
can find different types of cloud deployment
offerings by providers in the market – Public clouds,
Private clouds and Hybrid (this one is very
Depending on multiple factors such as security
requirements, Network access, Reliability, IT Staff
Skills, Cost organization can choose a specific
deployment model to suit its requirements.
Private Cloud. – This is a deployment where cloud infrastructure is operated for a single
organization. The organization can choose to host it in-house in their own datacenter or lease it
at a third party remote location. The key here is it is not a multi-tenant environment and is
more of a dedicated model. This model is best suited to allay concerns of security, ownership &
Public cloud –This deployment model is kind of opposite of private, where all