Sunday, February 16, 2014

Cloud Services

Services offered by Cloud
The term services in cloud computing is the concept of being able to use reusable, fine grained components across a vendor’s network. This is widely known as ―as a service. Offerings with as a service as a suffix include traits like the following:
  • Large scalability
  • Multitenancy, which allows resources to be shared by many users
  • Device independence, which allows users to access the systems on different hardware
1 Software as a Service (SaaS)
Software as a Service (SaaS) is the service based on the concept of renting software from a service provider rather than buying it yourself. The software is hosted on centralized network servers to make functionality available over the web or intranet. Also known as ―software on demand, it is currently the most popular type of cloud computing because of its high flexibility, great services, enhanced scalability and less maintenance. Yahoo mail, Google docs, CRM applications are all instances of SaaS. SaaS Provider Examples:
  • Google
  • Salesforce.com
  • zoho.com
                             
                                                                Figure: Cloud Layers

2 Platform as a Service (PaaS)
From SaaS, now the industry is moving towards Platform as a Service (PaaS). PaaS offers a development platform for developers. The end users write their own code and the PaaS provider uploads that code and presents it on the web. SalesForce.com’s Force.com is an example of PaaS. PaaS provides services to develop, test, deploy, host and maintain applications in the same integrated development environment. It also provides some level of support for the creation of applications. Thus PaaS offers a faster more cost effective model for application development and delivery.
PaaS Provider Examples:
  • Google
  • Microsoft
  • Force.com
3 Infrastructure as a Service (IaaS)
The final segment in the cloud computing is the infrastructure. Infrastructure as a Service (IaaS) is delivery of the computing infrastructure as a fully outsourced service. Some of the companies that provide infrastructure services are Google, IBM, Amazon.com etc. Managed hosting and development environments are the services included in IaaS. The user can buy the infrastructure according to the requirements at any particular point of time instead of buying the infrastructure that might not be used for months. IaaS operates on a ―Pay as you go‖ model ensuring that the users pay for only what they are using. Virtualization enables IaaS providers to offer almost unlimited instances of servers to customers and make cost-effective use of the hosting hardware. IaaS users enjoy access to enterprise grade IT Infrastructure and resources that might be very costly if purchased completely. Thus dynamic scaling, usage based pricing, reduced costs and access to superior IT resources are some of the benefits of IaaS.
IaaS is also sometimes referred to as Hardware as a Service (HaaS). An Infrastructure as a Service offering also provides maximum flexibility because just about anything that can be virtualized can be run on these platforms. This is perhaps the biggest benefit of an IaaS environment. For a startup or small business, one of the most difficult things to do is keep capital expenditures under control. By moving your infrastructure to the cloud, you have the ability to scale as if you owned your own hardware and data center.
IaaS Provider Examples:
  • Amazon
  • Rackspace
  • Joyent
  • GoGrid