Basics of Cloud Computting

Hello friends, this article explores the basics of cloud computing. Future articles on the cloud will be more detailed and based on Microsoft Azure.

Cloud Computing

Cloud computing is computing in which a large group of remote servers are networked to allow centralized data storage and online access to computer services or resources.

      - Wiki

Using a cloud

Yes, we are all cloud users, whenever we access applications using modern browsers we're using a cloud, for example, Gmail, Hotmail, Outlook OneDrive, Google Drive, Dropbox.

Companies offering a cloud

There are many cloud service providers that offer a public cloud:

• Microsoft Azure
• Google
• Amazon
• Rackspace

Uses of cloud computing

Clouds can provide users with a number of benefits.

Maintaining an Enterprise IT infrastructure is a costly affair since you need to handle many areas from procuring software, hardware, licensing costs, networks, database and so on. You need manpower and staff to manage and ensure availability too. This is a tedious job and cloud computing can save by offshoring this after leveraging the services of any cloud service provider.

There are many reasons why cloud computing is so widely popular:

• Reduction of costs: unlike on-site hosting, the price of deploying applications to the cloud can be less due to lower hardware costs from a more effective use of physical resources.
  
  
• Universal access: cloud computing can allow remotely located employees to access applications and work via the internet.
  
  
• Software updates: you're not bothered about software updates and OS patching. These things will be taken care of by the cloud service provider.
  
  
• Scalability: whenever you want to scale up/down your applications then it's very easy via the cloud.
  
  
• Flexibility: cloud computing allows users to switch applications easily and rapidly, using the one that suits their needs best.

Cloud composition

• Virtual servers: Many physical servers are consolidated into Virtual Servers depending upon how capable your physical server is. For example, one physical server can contain 50 or 80 virtual servers.
  
  
• Virtualization: A physical server has a virtual server instance called virtualization. Virtual machines are possible because of virtualization.
  
  
• Cluster: Two homogeneous virtual servers are made part of a cluster. This cluster can act as a fall-back or load balanced server.
  
  
• Hypervisor: This is the heart of virtualization, it's software layer introduced the following OS that interacts with the hardware of a physical server.
  
• Data Center (DC): a DC contains computer infrastructure, servers, backup mechanism, backup power supplies and network. Thousands of clusters joined together form DC.
  
  

Cloud service model

There are mainly 3 service models given as in the following.

Software as a Service (SaaS)

SaaS is a software delivery method that provides access to software and its functions remotely as a Web-based service. This happens by using modern browsers and there are millions of applications available online.

Example: Hotmail, Gmail.

Platform as a Service (PaaS)

Platform as a Service (PaaS) is a way to rent hardware, operating systems, storage and network capacity over the internet. It includes a variety of services, for example database integration, security and monitoring. Developers can host their application over PaaS picking a platform offered by the cloud service provider.

Example: Microsoft Azure Web Sites.

Infrastructure as a Service (IaaS)

Infrastructure as a Service is a provision model in which an organization outsources the equipment used to support operations, including storage, hardware, servers and networking components.

Example Microsoft Azure.

The following diagram will help you understand better, what all the components are that you manage when using various service models:



Cloud Storage

Data is centrally stored in the cloud and available across the internet. There are various storage options available or we can classify them broadly in the following three categories.

Public Cloud

In this model a service provider makes resources, such as applications and storage, available to the general public over the internet. Public cloud services may be free or offered on a pay-per-usage model.

Private Cloud

A private cloud provides more control over the company's data and under the control of the company's IT department.

Hybrid Cloud

A Hybrid Cloud is a combination of public cloud storage and private cloud storage, where some critical data resides in the enterprise's private cloud and other data is stored and accessible from a public cloud storage provider.



Summary of benefits of a cloud:

• Lower costs, “Pay as you use”
• Software updates
• Backups
• Data hosted centrally
• Scalability
• Fail over
• Monitoring services
• Data storage

I'm sure, friends, that you now have an idea of cloud computing and we'll have a deeper dive into future articles on it.