Introduction:

The word cloud means “the internet”. That is cloud computing, refers one kind of online based computer services where applications, servers, storage are shared to an organization’s computer and devices through the network. E-mail, web conferencing, customer relationship management (CRM) is all the applications which use cloud computing. The main objective of cloud computing is to dynamically reduce heavy workload of one particular computer for any running application and for the reason demands from the client’s side hardware and software decreases.

Cloud computing offers web based infrastructure, application and database. It also refers to manipulating, configuring, and accessing the applications online. Cloud computing overcomes platform dependency issues by not installing software on local computers. Hence, the business application mobile and collaborative is made by Cloud Computing very easily.

Three different kinds of service model provided by cloud computing. The services are accessed remotely over internet through user’s web browsers. The first service is SaaS i.e software as a service, this service refers software application provision for the cloud. Next, PaaS i.e. platform as a service, which allow clients to deploy the provision of services. In PaaS programming languages and tools are used to create application supported by suppliers. Lastly IaaS i.e. infrastructure as a service, it means in the cloud processing power, storage space and network capacity allow user to run different types of software. The combination of three services are called as cloud computing stack. Through this model customer can access from any network connected computer. It enhances the capacity of IT services rather dependent to storage space on local computer and not bind to limit the locally installed software.

Working procedure

Now it is necessary to know how the entire cloud computing network works. It is basically divided Front end and the back end, which are two main portions of Cloud computing systems which are connected by the internet. The client side is the front end and the “cloud” portion is the back end of the system. The client’s computer, i.e. front end is needed to access the application of computing system. Different types of computers, servers and data storage systems, i.e. the back end are needed to form the cloud computing network. In this architecture, a main central server controls the whole network, monitoring traffic; observe the total system, meeting user’s demands to smoothly maintain everything. Each computer in the network communicated with each other using protocols, and a software which is called as middleware. The power of cloud computing is enhanced by the Server virtualization method. Where It is possible to illusion of a physical server into thinking it’s actually multiple servers which is running with its own independent operating system. For now a day’s cloud computing technique adopted for different business benefits like time saving, financial growth, maintaining infrastructure etc. The environment of cloud network is divided into three categories, they are: public, private, hybrid and community clouds.

Public Clouds:

The Public Cloud allows systems and services to be accessible easily to the general network. Public cloud may, not more, secure due to its openness, e.g., e-mail.

Private Clouds:

It allows user to access system and services within organizations. Users used this network for data security and privacy, but the total cost of maintaining and setting up this network has to bear by one person.

Hybrid Cloud:

It is a combination of private, community or public network. However, the non-critical activities are performed using public cloud on the other hand the critical activities are performed using private cloud while. The Hybrid cloud network is usually found in an environment where users are shifting from private cloud to public cloud setup. In a Hybrid Cloud, 3rd party Cloud Providers may utilize by service providers with a full or partial manner thus increasing the flexibility of computing. This environment is capable of providing on-demand, externally provisioned scale. The ability to increase the power of a private cloud with the resources of a public cloud can be able to manage any kind of workload.

Community Cloud:

Group of organizations can able to access system and services of community cloud. Here limited number of clients with same requirements share the same infrastructure. From a financial point of view, this model is beneficial because the entire costs are divided between all the clients. Another benefit of this model is more security and privacy which is important for the protocol’s purpose. In a Cloud Computing environment, organizations would need to scale their applications, so that it uses the architecture models that Cloud Computing offers. Some of the typical advantages are listed below:

Reduced Cost:

There are a numerous reasons to use Cloud technology with lower costs. This business-oriented model services are paid as per usage; usually monthly subscription charge basis. The infrastructure is not purchased thus limiting maintenance cost. Initial expense and recurring expenses are much less than traditional computing.

Increased Storage:

Cloud providers offered the massive Infrastructure that is storage space & maintenance of large volumes of data is a reality. The cloud can scale dynamically because unexpected workload spikes are also managed effectively & efficiently.

Flexibility:

Flexibility is one of the very important topics. With organization having to adapt, very rapidly, to changing business conditions, speed to deliver is critical. Cloud computing stresses of getting applications to market very easily and quickly, the most appropriate building blocks are used as necessary for deployment.

• Access to resources: It is one of the most important benefits of cloud computing. Where multiple remote computers provide processing power accessibility. Thus, greater computation speed and larger storage allow user to take advantage that most organizations can provide at a lower cost.

Mobility:

From any location in the world users can able to access any kind of service. For this reason, the users can access any business information and services when he/she on the way.

• Data security: Cloud provides a superior storage of data than in-house storage space because it is offered by data centers. It is another important characteristic of organizations.
• Cloud computing offers load balancing which makes it more reliable.

Some of the common drawbacks are also here:

Internet reliability:

Lack of internet access or slow connections will disrupt IT services over the network. Where enterprise concern, those services are the biggest problem. There is no guarantee of uninterrupted internet services.

Complexity:

To maintain the system Database administrators have extra work to do.

Integrity:

If the database is very complicated or modified frequently then it is very difficult to maintain integrity of database system.

Standards:

Centralized database cannot be converted into a cloud database because there is no current standard available.

Management Capabilities:

Still infrastructure and management of platform management is very difficult though there are various cloud providers.

Regulatory and Compliance Restrictions:

customer’s of any of the European countries are not allowed as per Government regulations, to be physically located personal information or other sensitive information outside the state or country. To meet these requirements, cloud providers need to set up a data center or a storage site exclusively within the country to comply with the regulations. This infrastructure may not always be feasible and for that is a big threat for cloud providers.

Supplier Dependency:

Dependency on the supplier is the most common in organizations. In daily life customer is depended for access to the IT service rather than for support and maintenance. For these reason the risk assessment carried put to mitigate that risk.

Low Security:

Resources are shared publicly over a network in the public cloud model, for these reason security levels is not higher.

To make the cloud computing more reliable, flexible and usable some technologies are the following:

• Service-Oriented Architecture (SOA): Regardless, any type of technology, vendor or product of this Architecture helps to use the services of an application for another application. For these reasons different vendors can make changes to services without additional programming therefore data exchange between applications is possible.
• Grid Computing: It means to achieve a common objective bunch of computers from different locations are connected over the internet i.e. distributed computing. Grid Computing divided the complex task into smaller one. The pieces of smaller tasks are distributed to the geographically dispersed computer which is residing within the grid.
• Utility Computing: it is use computational resources on demand basis as a rented metered service. Basically, it is using a model name as Pay per Use model. Examples of these computing are IT services, Cloud computing etc.
• Virtualization: The term Virtualization refers a technique where a physical server or resources allow, to share within different users or enterprises by giving a logical name to physical resources as and when demanded.

Security and privacy are the most important issue of cloud computing. In corporate world some employee hesitates to take benefit of a cloud computing system because they want to keep their organization’s sensitive information into secure. Using cloud computing services any organization can rely about their security issues.

Besides security, privacy is another important matter. It is possible that client’s privacy could be disclosed when they log on to the network. Using Authentication method i.e using user name and password cloud computing providers can ensure privacy. Authorization is another form where every user can able to access only those data which is relevant to their work.