Cloud Computing - a Brief Introduction

Cloud computing is one of the most popular topic of discussion by business and IT executives in the last 3-years and it is moving along from a theoretical discussion to real implementation and becomes an unstoppable trend. It’s very much like the topic of Mobility 10-years ago and it is becoming main stream. I have written several articles on Mobility, so now I carry on with the discussion about Cloud Computing.

In this article, I will discuss what is the definition of Cloud Computing, development, The four characteristics and Three layers of Cloud Services.

Definition of Cloud Computing

Cloud computing is a computing model that leverages global network that allows us to get access of the computing resources which are flexible, fully configurable. Its computing resources or data storage can be very quickly raised or lowered according to the needs at the time (on-demand) that saves time and costs.

Development of Cloud Computing

Cloud Computing is not a revolutionary idea. The concept is evolutionary. Cloud computing integrates a wide range of existing and new technology to provide a new way of utilization of computing resources. As an example, cloud computing utilizing data access network either wired or wireless and internet. It is leveraging web-based applications, capabilities of servers and data storage which is constantly evolving and. With availability of ample of computing resources and very large volume of data storage, shared by a large number of users Cloud Computing can bring down rapidly the average cost of computing power and data storage.

The Characteristics of Cloud Computing

There are four characteristics of Cloud Computing:

• Resource Pooling

• Rapid Elasticity

• On-demand self-service

• Measured services

In Cloud computing, all computing resources, whether it's compute power, memory, networking, data storage is pooled to serve the needs of users in multi-tenancy. Physical and virtual computing resources are dynamically allocated to suit the needs of applications and users.

The second characteristic of Cloud Computing is Rapid Elasticity where cloud computing resources can be added and subtracted according to the needs of users and applications. For example, at the time the year-end shopping season will increase of the number of visitors of e-commerce site, computing resources for e-commerce site should be able to anticipate a surge of the number of page views and transaction processing but after the season is finished has to be lowered. Rapid Elasticity is very helpful to reduce costs because without rapid elasticity then the computing resources has to be made available higher even though not always used. For the manufacturing company we can see a scenario when launching of new products, if great demand is anticipated then computing resources prior to and at the beginning of the launch of the product must be able to cope with a surge and after the euphoria period finished then demand will be lower and the computing resources must be able to be adjusted down (on-demand).

The third characteristic of Cloud Computing is On-Demand Self-service, where users of cloud computing could directly interact with Cloud Services ranging from purchase, create, scheduling and utilization without any human intervention at all. On-Demand self-service allows users to define the extent of the resources that are needed now and for the future and to control its use and monitor how much has been used. In order to enable On-Demand self-service, Cloud Computing should use tools that give users access to the menu what resources Is available, at what price and who is the provider. These tools are called Self-Provisioning. By way of self-provisioning, without intervention of the operator, the costs of delivering can be lowered.

The fourth characteristic of Cloud Computing is Measured Services, meaning cloud computing, could measure the level of cloud computing resources usage by users. The system is used in Cloud Computing should provide the ability to measure how large computing resources, networking, data storage and the number has been consumed by users. Consumption level can be monitored, controlled and reported to the administrators of the users. A good metering process must provide transparent, reliable and can be monitored either by user and Cloud Computing providers.

IT as a Service

With the characteristics listed above, we can see the purpose of Cloud Computing is to allow the availability of computing resources that is no longer in the physical form anymore but in the form of as a service. There are three levels as a Service.

• Software as a Service (SaaS)

• Platform as a Service (PaaS)

• Infrastructure as a Service (IaaS)

The following diagram can describe three layers of Cloud Services, and its required components

Software-as-a-Service (SaaS)

it could be referred to as an Application as a Service. This form of cloud Services are applications that can be accessed by users using a Web-browser. The easiest example is Hotmail or Gmail, Google Docs or Microsoft Office 365. Another example of a very popular nowadays are Social Media Applications such Facebook, Instagram, Whatsapp and Twitter. Another common example is an application to backup personal data (Backup as a Service). For business use examples are Salesforce.com, Workday.  

Platform-as-a-Service (PaaS)

This Cloud Services is associated with lower levels of services and does not relate directly to the users (end-users). PaaS is related to the operating system and programming language required by application developers. Application developers write the application according to certain standards (platform) and after they finished writing their application, they could upload the coding that they have written automatically to PaaS. With PaaS, all computing resources required to run application will be made available, hence application developers do not need to worry the resources (servers, Connectivity, Storage) which are required by the application. One of the most important characteristics of PaaS is auto-scaling. Microsoft Windows Azure and Google App Engine are good examples of PaaS.

 Infrastructure-as-a-Service (IaaS)

This Cloud services provides virtual server (known as VM/Virtual Machine) and data storage (Storage as a Service) which can be accessed by the user and paid based on the amount of use (pay per use or a pay as you go). This type of Cloud Services are the most widely available and used.