Cloud Computing

What is Cloud???

The cloud is a computing service that charges you based only on the amount of computing resources we use.

Pay as you go

lVirtualization: 
The ability to run multiple operating systems on a single physical system and share the underlying hardware resources.

Cloud Computing: 
The provisioning of services in a timely (near on instant), on-demand manner, to allow the scaling up and down of resources

Key Characteristics :

Agility
Cost
Device independency
Reliability
Scalability
Security
Sustainability

Components in Cloud Computing :

Client
Services
Application
Platform
Storage
Infrastucture

Normally technology is organized into three layers that are placed like a pyramid:

Cloud Computing Architecture:

Infrastructure as a service (IaaS)
Platform as a service (PaaS)
Software as a service (SaaS)
Network as a service (NaaS)
Storage as a service (STaaS)
Security as a service (SECaaS)
Data as a service (DaaS)
Desktop as a service (DaaS - see above)
Database as a service (DBaaS)
Test environment as a service (TEaaS)
API as a service (APIaaS)
Backend as a service (BaaS)

Software as a Service :

Software as a service feature a complete application offered as a service demand single instance of the software runs on the cloud and services multiple end users or client organization

Ex : Google Apps

Platform as a Service :

Platform as a Service  encapsulates a layer of software and provides it as a service that can be used to build higher level services

2 perspectives for  Platform as a Service

1. Producer
2. Consumer

Infrastructure as a Service :

Infrastructure as a service delivers basic storage and computing capabilities as standardized services over the network

Computing Types :
Cloud computing comes in three forms: public clouds, private clouds, and hybrids clouds. Depending on the type of data you're working with, you'll want to compare public, private, and hybrid clouds in terms of the different levels of security and management required.

Public Clouds

A public cloud is one in which the services and infrastructure are provided off-site over the Internet. These clouds offer the greatest level of efficiency in shared resources; however, they are also more vulnerable than private clouds. A public cloud is the obvious choice when

Your standardized workload for applications is used by lots of people, such as e-mail.

You need to test and develop application code.

You have SaaS (Software as a Service) applications from a vendor who has a well-implemented security strategy.

You need incremental capacity (the ability to add computer capacity for peak times).

You’re doing collaboration projects.

You’re doing an ad-hoc software development project using a Platform as a Service (PaaS) offering cloud.


Private Clouds

A private cloud is one in which the services and infrastructure are maintained on a private network. These clouds offer the greatest level of security and control, but they require the company to still purchase and maintain all the software and infrastructure, which reduces the cost savings. A private cloud is the obvious choice when

Your business is your data and your applications. Therefore, control and security are paramount.

Your business is part of an industry that must conform to strict security and data privacy issues.

Your company is large enough to run a next generation cloud data center efficiently and effectively on its own.


Hybrid Clouds

A hybrid cloud includes a variety of public and private options with multiple providers. By spreading things out over a hybrid cloud, you keep each aspect at your business in the most efficient environment possible. The downside is that you have to keep track of multiple different security platforms and ensure that all aspects of your business can communicate with each other. Here are a couple of situations where a hybrid environment is best.

Your company wants to use a SaaS application but is concerned about security. Your SaaS vendor can create a private cloud just for your company inside their firewall. They provide you with a virtual private network (VPN) for additional security.

Your company offers services that are tailored for different vertical markets. You can use a public cloud to interact with the clients but keep their data secured within a private cloud.