Piston:Getting started
What is a cloud?
The term cloud is often user with really understanding its meaning. Its a term used across a number of different disciplines to describe a group of things that appear as one, from a distance, such as:
- Meteorology: A waether cloud is a mass of water droplets
- Mathematics: A larger number of points on a graph is a point cloud
- Astronomy: Star Clouds
In computing a cloud refers to a collections of computing technologies that work together to provide a service. While this definitions can be applied to a large number of systems, cloud computing is defined by serveral traits:
- Rapid elasticity - capabilities are easily scaled
- Measured Service - monitoring by consumption
- On demand self service - Provision as much as you need
- Broad Network - Access any where on any device
- Resource Pooling: Infrastructure is shared
Three Technologies of Cloud
Types of Cloud
There are three types of clouds that can be developed: Private, public and hybrid.
Public
Provisioned by a single organization of use by the public - eg Amazon Web Services
Private
Provisioned by a single organization of use by that organization - Nasa
Hybrid
A cloud that spans public and private infrastructure. Allows a company to fully utilize their local hardware, but make use of public systems at time of high load.
Cloud Service Models
- Insfrastucture as a Service (IaaS) - Hardware including serversm storage and networking on demands in a pay as you go model
- Platform as a Service (PaaS) - Geared towards facilitating the creatation and deployment of applications and services - PaaS provides instructure along with solution specific toolkits.
- Software as a Service (SaaS) - Subscription based and centrally hosted application that is access over the web
Cloud and Virtualization
Cloud computing does into mean virtualization!!! A cloud provides a service, which may or many not invclude virualization.
Virtualization on the other hand simulates a hardware platform.