what is Cloud Computing..?

The Cloud Computing

       One of my Junior joined the company straight after the college he asked me many doubts about cloud computing which i feel worth sharing with the web community. In this blog post my aim is to make person understand what cloud computing is all about?

What is Cloud? Or What is Cloud Computing?

    Using the Computational resources ( like servers) from some a persons (cloud vendors) who owns, maintains the hardware devices and in return paying them for the service which we used. 

Why the name Cloud Computing?

In network diagrams the Internet usually is represented as a cloud.Thus using computing resources from the Internet is eventually called as cloud computing.

Cloud Computing Service Models

There are 3 ways through which cloud computing offers service.

1. Infrastructure as a service ( IaaS)
2. Platform as a service ( PaaS )
3. Software as a service (SaaS)

What is Infrastructure as a service or IaaS?

         In Infrastructure as a Service Cloud Computing, the Cloud vendor give the computers as physical machine or as a virtual machine for hosting application(web server), storing files (storage server), using proxy (proxy servers). They usually give the IP address of the computer in which the service is available.The Cloud infrastructure is usually managed by a web interface which is given by the cloud vendor.Using the Web Interface given by the cloud vendor functions like adding the RAM ,adding hard disk etc can be done.

Infrastructure as a service Examples: 
 Amazon Web Services from Amazon.

·         GoGrid : Dedicated server,Cloud Storage, and F5 hardware load balancing

·         Flexiscale: Europe based cloud computing.

·         Eucalyptus: Software platform for the implementation of private cloud computing.(open source).

What is Platform as a service or PaaS?

          In Platform as a Service Cloud Computing, the Cloud vendor give the platform for computing (like building, running, managing custom applications) over the internet.Usually a Integrated Development Environment(IDE) including the operating system, database , webserver etc.,

Platform as a service Examples: 

·         AppEngine from Google: based on Python and Django

·         Force.com from SalesForce: based on the SalesForce SaaS infrastructure and Apex language

·         Bungee Connect: visual development studio based on Java

·         LongJump: based on Java/Eclipse

·         WaveMaker: visual development studio based on Java and hosted on Amazon EC2

·         Appscale: visual development studio based on Java and hosted on Amazon EC2

What is Software as a service or SaaS?

       In Software as a Service Cloud Computing, the Cloud Service Provider supplies the infrastructure with the software product.We as a user usually consume the software through the web interface. 

Software as a service Examples

·         SalesForce -offers Customer Relationship Management Software over the cloud (internet).

·         ForceMicrosoft Office Online.com from Microsoft : offers MS-Office Software over the cloud.

·         Gmail from Google: offers web based Mailing software.

·         Google Docs - from Google: offers MS office kind of software which includes docs, PowerPoint, spreadsheet  over the cloud at free of cost.

Advantages of Cloud Computing

• Pay as you go model
• Elastic - The infrastructure can be expanded on the go.
• Managed - as it is highly automated.
• More Mobility (Remote Accessibility) - you can use your cloud infrastructure from anywhere.
• Reduced Cost (May be in some cases).

Disadvantages of Cloud Computing

• Privacy : As the data is managed by some others (Cloud Vendor).
• Security.
• Risk of losing Internet Connectivity.

Famous Cloud Vendors

• Amazon Web Services
• Appistry
• AppScale
• AT & T Cloud Services
• Engine Yard
• Enomaly
• FlexiScale
• GCloud3
• Gizmox
• GoGrid
• Rackspace
• Google Cloud Computing
• Long Jump - Online Database (PaaS)
• Microsoft Azure
• OrangeScape - Visual PaaS
• Terremark
• Ubuntu Cloud
• Verizon
• VMware, Cisco Systems And EMC

The below image from Rackspace.com explains about cloud.