Cloud Computing: Introduction in a simple way

Cloud Computing

                                                                                   By:  Jayant Sharma

                                                                                    

Client - Server Architecture

Client- server architecture is a system architecture in which the client requests some resources and the server hosts, delivers and manages those resources and services. This architecture can have one or more client computers connected to a central server through a network or internet connection.

In general, it partitions tasks or workloads between the providers of a resource or service, called servers, and service requester, called clients. A client does not share any of its resources, but requests a server's content or service function. The communication is always initiated from client side.

Client-server architecture is also known as a Networking computing model or client-server network.

Cloud Computing Introduction

Cloud Computing provides us a method through which we can access the applications and various utilities over the internet. The term Cloud refers to a Network or Internet.

Cloud allows us to manipulate, configure, and access various resources from anywhere, anytime through network. It offers various facilities like online data storage, infrastructure, and application.

Since, Cloud computing is done through an internet or a network, it offers platform independence.

Cloud Computing Models

Following are the working models for cloud computing:

• Deployment Models

• Service Models

• Infrastructure-as–a-Service (IaaS)

• Platform-as-a-Service (PaaS)

• Software-as-a-Service (SaaS)

• Front End

• Back End

Advantages of Cloud Computing

Cost Savings

Reliability

Manageability

Downtime

Security

Vendor Lock-In

Limited Control

Deployment Model: It define that how we are going to the cloud. That means it defines the type of access we are using. The types are as follows:

• Public Cloud
• Private Cloud
• Hybrid Cloud

Public Cloud: It allows systems and services to be easily accessible to the general public. Since, due to its availability to everyone as a general public, it becomes less secured.

Private Cloud: It allows systems and services to be accessible within an organization only. It is most secured because of its private nature.

Hybrid Cloud: It is a mixture of public and private cloud, in which the critical activities are performed using private cloud while the non-critical activities are performed using public cloud.

Service Model: There are following types of service models:

IaaS provides access to fundamental resources such as physical machines, virtual machines, virtual storage, etc.

PaaS provides the runtime environment for applications, development and deployment tools, etc.

SaaS model allows using software applications as a service to end-users.

Historical Development of Cloud Computing

Before the concept of cloud computing, there was Client/Server computing present but not advance as we have now. It was basically a centralized storage in which all the software applications, all the data and all the controls are resided on the server side. If a user wants to access specific, he/she need to connect to the server and then gain appropriate access, and then he/she can do his/her business. Then after that, Distributed Computing came into picture, where all the computers are networked together and share their resources when needed. On the basis of above computing, the concept of cloud computing was introduced and implemented. At around in 1960s, John McCarty suggested in a speech at MIT that “computing can be sold like a utility, just like a water or electricity”. It was a brilliant idea, but it was ahead of its time, as for the next few. But time has passed and the technology caught that idea and after few years we mentioned that:

In 1999, Salesforce.com started delivering of applications to users using a simple website. The applications were delivered to enterprises over the Internet, and this way the dream of computing sold as utility were true.

In 2002, Amazon started Amazon Web Services, providing services like storage, computation and even human intelligence. However, only starting with the launch of the Elastic Compute Cloud in 2006 a truly commercial service open to everybody existed.

In 2009, Google Apps also started to provide cloud computing enterprise applications.

In 2009, Microsoft launched Microsoft Azure.

This proves that today, cloud computing has become mainstream.

Why Cloud Computing

For any organization, we a Server is needed that is the basic need of organization. The server contains a network, firewalls, routers, modem, switches, configurable system, database, email servers etc. To establish such IT infrastructure, we need to spend lots of money. To overcome all these problems and to reduce the IT infrastructure cost, Cloud Computing comes into existence.

Cloud Computing Architecture

Cloud Computing architecture is broadly divided into two parts:

Each of the ends is connected through a network, usually Internet.

Front End: It refers to the client part of cloud computing system. It consists of interfaces and applications that are required to access the cloud computing platforms, Example -Browser.

Back End: It refers to the cloud itself. It consists of all the resources required to provide cloud computing services. It comprises of huge data storage, virtual machines, security mechanism, services, deployment models, servers, etc.

It is the responsibility of the back end to provide built-in security mechanism, traffic control and protocols.

The architecture is shown in figure below,

Picture source:

https://www.tutorialspoint.com/cloud_computing/cloud_computing_architecture.htm

The most significant cloud computing benefit is in terms of IT cost savings.

With a managed service platform, cloud computing is much more reliable and consistent than in-house IT infrastructure.

Cloud computing provides enhanced and simplified IT management and maintenance capabilities through central administration of resources.

Disadvantages of Cloud Computing

As cloud service providers take care of a number of clients each day, they can become overwhelmed and may even come up against technical outages. This can lead to your business processes being temporarily suspended.

Although cloud service providers implement the best security standards and industry certifications, storing data and important files on external service providers always opens up risks. Using cloud-powered technologies means you need to provide your service provider with access to important business data. Meanwhile, being a public service opens up cloud service providers to security challenges on a routine basis.

Cloud service providers promise that the cloud will be flexible to use and integrate; switching cloud services is something that hasn’t yet completely evolved. Organizations may find it difficult to migrate their services from one vendor to another. Hosting and integrating current cloud applications on another platform may throw up inter-operability and support issues. For instance, applications developed on Microsoft Development Framework (.Net) might not work properly on the Linux platform.

Since the cloud infrastructure is entirely owned, managed and monitored by the service provider, it transfers minimal control over to the customer.

Cloud Service Providers

IaaS service providers- Amazon Web Service, Microsoft Azure.

PaaS service providers- Apprenda, Red Hat Open Shift.

SaaS service providers- Google Applications, Salesforce.