Journal of Emerging Trends in Computing and Information Sciences ©2009-2012 CIS Journal. All rights reserved. http://www.cisjournal.org
Exploring Cloud Computing Services and Applications
Ahmed E. Youssef
Dept. of Information Systems College of Computer and Information Science KSU, Riyadh, KSA firstname.lastname@example.org
Cloud computing environment provides a great flexibility and availability of computing resources at a lower cost. This emerging technology opens a new era of e-services in different disciplines. In this paper, we explore cloud computing services and applications, we give examples for cloud services provided by the most common Cloud Service Providers (CSPs) such as Google, Microsoft, Amazon, HP, and Sales force and we present innovative applications for cloud computing in e-learning, Enterprise Resource Planning (ERP) and e-governance. Our study helps individuals and organizations understand how cloud computing can provide them with customized, reliable and cost-effective services in a wide variety of applications. Keywords: Cloud Computing, ERP, e-learning, e-government, Service-Oriented Architecture, Pay-Per-Use, SaaS, PaaS, IaaS.
Cloud computing is a topic that received a great deal of attention by individuals and organizations from different disciplines in the last decade [1-20]. This new environment implies great flexibility and availability of computing resources at different levels of abstraction at a lower cost. Cloud Service Providers (CSPs) (e.g., Google, Microsoft, Amazon) are vendors who lease to their customers cloud computing resources and services that are dynamically utilized based on customer’s demand according to a certain business model . General services in different application areas such as business, education and governance are provided to the customers online and are accessed through a web browser, while data and software programs are stored on the cloud servers located in the data centres . These services are generally classified into three classes known as cloud service models and are shown in figure 1. Cloud service models [1,2,12,13,18,19,22,24,26-29,34] are a Service-Oriented Architecture (SOA) that describe cloud services at different levels of abstraction. These models are: Software as a Service (SaaS): In this model, CSPs are responsible for running and maintaining application software, operating system and computing resources. The customer views the SaaS model as a web-based application interface where services and complete software applications are delivered over the Internet and are accessed via a web browser. Customers can access hosted applications such as Gmail and Google Docs through different client devices such as laptops, iPads and cell phones. Unlike traditional software, SaaS has the advantage that the customer does not need to buy licences, install, upgrade, maintain or run software on his own computer . It has also other advantages such as multitenant efficiency, configurability and scalability . Examples of SaaS providers are Zoho, Google Apps and Salesforce.com. Platform as a Service (PaaS): In PaaS, a CSP provides, runs and maintains both system software (i.e., the operating system) and computing resources. The customer manages and runs the application software under the operating system and on the virtual resources provided by the CSP. The customer has little or no control over the operating system and hardware resources .Unlike SaaS that provides the customer with complete (ready to use) applications, PaaS gives him/her the opportunity to design, model, develop and test applications directly on the cloud; therefore, he/she can control the software lifecycle . PaaS supports collaborative work between members of a project team. For instance, a number of users located in different countries can collaborate in developing a website using a PaaS cloud service....