Cloud Basics –part2

In part 1 ,i tried to cover what is cloud computing and what are the benefits of it . So lets see how the cloud services have defined.

Types of Cloud Service Models:

  1. Infrastructure as a service
  2. Platform as a service
  3. Software as a service
  4. Business process as a service

IaaS (Infrastructure as a Service):

In the name itself saying that infrastructure will be provided as a service.

A service model that involves outsourcing the basic infrastructure used to support operations including storage, hardware, servers, and networking components.

IaaS delivers computer infrastructure, typically a platform virtualization environment, as a service. Rather than purchasing servers, software, data center space or network equipment, clients instead buy those resources as a fully outsourced service.

Cloud user can install OS images on the VM and their application software and user is the only responsible for the maintenance of OS and application software.

Iaas services are billed on a utility computing basis means cost reflects the amount of resources allocated and cosumed.

E.g.: Amazon AWS, Rackspace cloud, Google computer engine and right scale.

PaaS (Platform as a service):

In PaaS , the vendor provides both the basic infrastructure and platform .So we can say PaaS is the extension of IaaS where cloud user will be served with Infrastructure as well as right  platform to deploy his/her application.

So what is meant by platform and what are all the things the vendor provides?

Platform means the computing platform like OS, Programming language execution environment, database server and the web server. All these are managed by the vendor along with the physical infrastructure so customer will be benefited by avoiding the cost and complexity of buying and managing the underlying software and hardware.

So the developers can develop and run their software applications on the PaaS platform.

E.g.: Amazon elastic beanstalk (php, .net, java),

        Google app engine (python, java, go)

        Microsoft Azure (.net, php, java, go)
 from sales force and IBM blue mix.

SaaS (Software as a Service):

This is a type of service model where our day to day applications like google apps is following. Everything will be provided by the vendor, just cloud user need to access over the internet.

SaaS, sometimes called as “software on demand “, the vendor provides the infrastructure, Platform and also the software/applications. The customer access the application over the internet.

Cloud applications have “elasticity “to meet the changing workload. To accommodate a large number of cloud users, cloud applications are usually multitenant – an application serves many organizations.

The pricing model is per transaction or per month or per user.

E.g.: Google apps (Mail, docs, calendar)

        Quick books online

BpaaS (Business process as a Service) :

BpaaS is a form of business process outsourcing (BPO) that employs a cloud computing service model.

BpaaS implies that the business process is being automated through a remote delivery model .

BPO is to reduce labour costs, BpaaS reduces labour count through increased automation, there by cutting costs in the process.

The pricing models are consumption based or subscription based commercial terms


fig :Cloud main Service Models

Cloud Stack:

 Traditional v/s IaaS v/s PaaS v/s SaaS


Above Model clearly illustrates how the services are offered by the vendors to the cloud users or clients. In traditional model , if a  user want to deploy and run an application , he/she need to have all the infrastructure like servers ,networking devices etc , software’s and the more skilled workers to set up a platform to run the application. With the traditional model there is lot of money need to invested the application owner where still the efficiency is an issue for the owner.

But the with the arrival of the cloud computing, everything is changed and user can deploy and run his application with less money and greater efficiency. User has the choice to choose any of the service model based upon his requirement. The infra is managed by the cloud vendor based different types of pay models.

This is  all about cloud service models in very brief . In the next article i will explain about cloud deployment models.

Don’t forget to share your feedback . Happy learning


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