26-06-2013, 04:56 PM
CLOUD COMPUTING: A POWERFUL ALTERNATIVE TO CHANGING GLOBAL NEEDS – A REVIEW
POWERFUL ALTERNATIVE.doc (Size: 316.5 KB / Downloads: 20)
ABSTRACT
The term cloud was coined by Professor John Mc Cathy as early as 1960 who suggested that computing power and even specific applications would be organized as a public utility. With the technological needs changing with every passing day, the amount of money lost in upgrading software, hardware and maintenance costs is becoming a matter of concern. Cloud computing is an answer to all the above addressed problems. The various models, types of cloud computing services and most importantly, how cloud computing web-based applications will revolutionize the way we work online have also been discussed. The present work also tries to clear few misconceptions about cloud computing. Furthermore, the pros and cons of cloud computing and the challenges like privacy, security, access, etc being faced today have also been citied.
Introduction
With information multiplying each day and making things more difficult to manage efficiently.IDC says that in coming 10 years, the amount of data to be stored will be 44 times the current rate of data growth as shown in Fig-1. And the amount of money lost in upgrading systems so as to match technological needs, storage, server, etc are to be noted. [1]
Cloud Computing Services
There are three types of cloud computing services being offered by the cloud namely-Software as a Service (SaaS), Infrastructure as a Service (IaaS) and Platform as a Service (PaaS) as shown in Fig.-3.
Software as a Service (SaaS)
SaaS- This is the most familiar of all cloud services. It provides any software application as a service through the cloud. It can also be explained as software that is developed and hosted by the SaaS vendor and the user accesses it over the internet. The various examples include Salesforce.com, Google’s Gmail and Apps, instant messaging from AOL, Yahoo and Google, and Voice-over Internet Protocol (VoIP) from Vonage and Skype.
Infrastructure as a Service (IaaS)
IaaS- This is the delivery model in which organization is given control over different applications and resources. The resources include hardware, software, servers and networking components, etc. This model provides flexibility to the users by providing infrastructure depending on his needs at a time. This can also be defined as “pay as you use” model.
The various examples include Amazon’s Elastic Computer Cloud (EC2) and Simple Storage Service (S3). But traditional IT vendors such as IBM and telecom providers such as AT &T and Verizon are also offering solutions.
Platform as a Service (PaaS)
PaaS- This model allows user to develop applications on the vendor’s provided infrastructure platform and deliver it to the users via internet. The key benefit of using this model is that it saves huge amount of cost which was spent in buying and managing hardware and software. It also provides facilities like application development, testing and hosting.
The examples of this model are Salesforce.com and Microsoft’s Azure.
Cloud Deployment Models
Most of the times cloud computing is often misunderstood as Internet cloud. Its very important to understand the difference between the two in order to use cloud effectively. There are basically three types of cloud models- Public, Private and Hybrid.
Public Cloud
It refers to the resources (hardware, software, applications) that are provided by the service
E-mail if hosted with an ISP is the oldest type of public cloud service. The public cloud uses the principle of “Pay as You Go” model. The key benefits of moving to the public cloud is that one don’t need to worry about managing the underlying IT infrastructure –no security patches or updates to apply, no software updates, etc. All these are to be taken care by service provider.
Private Cloud
It refers to having privately owned public cloud computing infrastructure. A public cloud is more suited for large enterprises. A private cloud typically involves optimizing the existing IT infrastructure so as to deliver faster services to the user. It allows IT team for provision for new hardware, software, services as per needs. It helps reduce costs, improve response time, and provides greater flexibility.
Hybrid Cloud
This model is actually a combination of the above two i.e.-public and private cloud model. Secure and critical operations are hosted in public cloud whereas not so critical ones are hosted in public cloud. The concept of hybrid cloud is yet to gain momentum primarily for infrastructure. Over a period of time, this is set to change where large enterprises will increasingly focus on hybrid cloud to make the best use of both the worlds.