Cloud Computing-I

In this first part of cloud computing we will only understand what is cloud computing and its three service model. Before understanding what is cloud computing let us consider a simple example for understanding the concept of cloud computing. For example if you want to read a book what would you do? The answer is that you would go to library and then take this book for a week or some days and then return it. For this you do not have to purchase whole library or the book store. Cloud computing is similar to the above explained example in which user uses the services provided on cloud based on some subscription period. Some popular examples of cloud computing are Gmail or Google drive. We can send mail using Gmail and also our mails are stored in it. In Google drive we can upload our pdf or word documents in it. The email management software and server is all on the cloud (internet) and is managed by the cloud service provider such as Yahoo or Google. You do not have to purchase email management software for it. In these type of services you just need an internet connection. These all are some examples of cloud computing. Let us understand the definition of cloud computing-

Cloud computing is a service in which we can use computing resources such as hardware or software over a network (typically the internet).images

Cloud Computing is based on three service models and they are-

1) Software as a Service (SaaS)

2) Platform as a service (PaaS)

3) Infrastructure as a Service (IaaS)

In this article we will see each model in detail-

1) Software as a Service (SaaS)- In this type of application cloud provider install and operate application software on cloud. The end user can then use this software without the need to install it on their computer. This reduces the maintenance and support that is required for the software.

Some common advantages of this type of model are-

  • Users can use this type of service anywhere, without the need to install them on their pc.
  • As software is maintained centrally on cloud so there will be no issue of version compatibility.
  • Hardware will not be required on user’s pc to use this type of software.

Example of SaaS provider-

2) Platform as a Service (PaaS)- In this type of model computing platform is provided to the end users for developing different applications. Computing platform includes web server, database, execution environment and operating system. Application developers develop their software solutions and can run it on the platform provided by cloud providers. Application can be developed using variety of platform such as Java, Python, .NET, Ruby etc.

Some common advantages of this type of model are-

  • As computing platform is provided by cloud providers hence developers can focus on application code and business logic.
  • As code runs on the platform provided by the cloud provider hence it reduces the need for some extra hardware.

Example- Google App engine is the best example of PaaS model.images (1)

3) Infrastructure as a Service (IaaS)- In this type of service model, instead of purchasing servers they are taken on rent and users pay for the use. This infrastructure consist of servers, storage and network. Instead of buying the whole infrastructure clients can use it on some subscription period. In IaaS an organization or company can use single server or the entire data canters.

Some common advantages of this type of model are-

  • Less power consumption
  • Less hardware resources
  • Servers can be deployed easily within few

Why to use this type of computing??

1) Availability-

Cloud provides services through many servers and even if one server goes down the other will be available for providing service. For example Amazon web services gives 99.999999% availability which is not possible in other type of services.

2) Low cost-

As companies uses the infrastructure provided by cloud hence automatically the cost required for maintaining this infrastructure will be reduced. Infrastructure will be maintained by cloud providers.

3) Multitenancy-

It provides advantage as multiple users use a shared pool of resources. This can be compared to a building in which there are many offices. In this, building can be considered to be shared pool of resources and different offices could be considered as users using this shared pool of resource (building).

4) Scalability-

Scalability can be used for increasing our application storage without a second’s down time. Scalability is important when you want to run your application at peak time. For example if there is an online shopping festival then the on network traffic will naturally increase. So to handle such a large traffic cloud resources can be used.

In the next part of cloud computing we will see deployment model, security issues in cloud computing and some important file systems in cloud computing.


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