“Cloud Computing” the BUZZ is in the Air – Part 2

Sundeep Malik

Information Technology Management

December'08

Welcome to my second post on Cloud Computing, this article speaks about the Ontology of the cloud. Though there is no industry defined ontology for the cloud, I found this particular representation most appropriate.

As seen in the figure the cloud is divided into five layers:

Cloud Applications: This is the most visible layer to the end users; it exports the work from the end users to the datacenters where the cloud applications run. It is normally referred to as Software as a service (SaaS). Examples are google apps, salesforce.com

Cloud Software Environment: This layer provides the application developers with a programming language level environment with a set of well defined API’s facilitating the interaction between environment and the cloud applications. It is also referred to as platform as a service (PaaS). Examples are Google App Engine, Sales Force Apex, Microsoft Azure

Cloud Software Infrastructure Layer: This layer provides computational resources, data storage and communication services. VM (Virtual Machines) are the most common form for providing computational resources to the cloud user and such services are dubbed as Infrastructure as a service (IaaS) examples are Amazons Elastic Compute Cloud, GoGrid, Skytap, Flexiscale, ElasticHosts, AppNexus. Data Storage is another software infrastructure provided that allow users to store data at remote disks and be billed according to their usage. The service is referred to as Data storage as a service (DaaS). Examples are Google App Engines Big Table, Amazon Simple DB (database for application development), Iron Mountain, Amazon Simple Storage Service, Nirvanix, CloudNAS, MobileMe iDisk. Communication as a service (CaaS) handles the task of providing service oriented communication capability that is reliable and secure, example being Skype.

Software Kernel: This layer provides software management for the physical servers that constitute the cloud. They can be implemented as an OS kernel, hypervisor, virtual machine monitor, or clustering middleware.

Hardware and Firmware: Is the actual physical hardware forming the backbone of the cloud. The users of this layer are normally big enterprises with huge IT requirements in need of subleasing.

That’s all I have in this week’s post, in the next post I will write about the different types of clouds and on Interoperability between various cloud service providers.