"Heads in the Cloud "

"Nee" came back from 2010 Developer Summit and was talking about Cloud computing with a lot of enthusiasm.  I read up on the topic and found the concept pretty interesting. All of us have used it but may have seldom realized that the underlying technology is cloud computing.

What is Cloud Computing?
Cloud computing is nothing but hosted services over internet. Cloud is a metaphor for internet.


OK, And ?
Companies on a general have their own applications , databases and infrastructure set up in their data centres. Once the cloud computing method is adopted, all you have to do is load one application which will allow employees to login to a web based service which hosts all programs to do their job .
The remote machines owned by the service providers will run everything from email to data processing to complex data analysis programs. This is cloud computing.

These hosted services are divided into 3 categories.

• I-a-a-S = Infrastructure as a service. I-a-a-S is a model in which the organisation outsources the equipment to support operations including storage, hardware , servers and networking components. The service provider owns the equipment and is responsible for housing, running and maintaining it. E.g. Amazon Web services { Physical assets as services }
• P-a-a-S = Platform as a service. Model for delivering operating systems and other services without downloads or installations. Set of software and development tools are hosted on providers infrastructure. Called as cloud ware because its moves resources from privately owned company to the internet. E.g. Google Apps, Force.com { Resources on demand }
• S-a-a-S = Software as a service. Software distribution model in which applications hosted by vendor or service provider are made available to the customer over the internet. Front end of the cloud. E.g Gmail, Pay roll, Google Calender, HR, CRM, IBM Lotus Live { Services on Demand }

Architecture ?
The cloud computing architecture has front end and a back end connected to each other via a network usually internet. Front end is the side which the computer user/client sees it. The back end is the cloud section of the system. Front end includes client computer and applications to access the cloud. Back end consists of computers , servers, storage. A central server administrates the system for traffic and ensures that the system runs smoothly. It follows a set of rules called as protocols and uses special software called as middle ware that allows networked computers to connect to each other.

Types of Cloud Computing ?

• Public : sells services to anyone on Internet. Largest public cloud service  provider is Amazon Web services.
• Private : Proprietary data centre that hosts services for limited number of people. 

Advantages ?

• Data centres  are under utilized often idle 85% of the time.
• Cost effective solution to key business demands ( Pay on use )
• Move work loads to improve efficiency.
• Choice and Agility
• Encapsulated Change management
• Next generation Architectures

Disadvantages  ?

• Governance { Security , Privacy and Control ; SLA Guarantees , Ownership and Control, Compliance and Auditing ( SOX ) }
• Reliability { Amazon went down for 6 hours and gmail issue last year for almost a day }
• Lock in

Commercial Clouds ?