Cloud Computing

Cloud Computing

Cloud Computing

Introduction

CLOUD computing, an emerging form of computing using services provided through the largest network (Internet or CLOUD) is becoming a promising alternative to the traditional in-house IT computing services. CLOUD computing is a form of computing in which providers offer computing resources (software and hardware) on-demand. All of these resources connected to the Internet and provided dynamically to the users. Figure 1 shows a schematic representation of CLOUD computing. Here, CLOUD computing providers connected to the Internet and able to provide computing services to both enterprise and individual users. Some companies envision this form of computing as a single major service which demanded extensively in the next decade. In fact, companies like Google, IBM, Microsoft, HP, Amazon, and Yahoo among others have already made investments not only in CLOUD research but also in establishing CLOUD computing infrastructure services. CLOUD computing services fall into three major categories1: (1) infrastructure as a service (IaaS), (2) software as a service (SaaS), and (3) platform as a service (PaaS). In IaaS virtualized servers, storage and networks provided to the clients. SaaS focused on allowing clients to use software applications through web-based interfaces. A service targeted to developers who focus primarily on application development only, without dealing with platform administration (operating system maintenance, load balancing, scaling, etc.), called PaaS. Advances in visualization, distributed computing, and express network technologies have given further impetus to CLOUD computing.

Body: Discussion and Analysis

The major advantages of CLOUD computing are scalability, ?exibility, resilience, and affordability. However, as users (companies, organizations, and individual persons) turn to CLOUD computing services for their businesses and commercial operations, there is a growing concern from the security and reliability perspectives as to how those services rate. The serviceability measurement can be categorized into three areas: performance, reliability, and security. Performance and reliability are two characteristics related to the condition of the providers' infrastructure and the way they maintain and update them. Security(data protection and disaster recovery), on the other hand, is one aspect that is more difficult to measure. Both CLOUD computing providers and users need a way to measure the quality of this service, mainly in the area of reliability and security. This metric can provide the sending and receiving end-users with a better sense of what both parties are getting for their return of investment. Also, it gives providers a concrete numerical reference, rather than vague attributes, so they can improve the quality of the current service. However, despite obvious benefits, CLOUD computing lacks rigorous analysis regarding its quality of service. Speci?cally, a quantitative assessment of the quality of service (QoS) in such enterprises leaves much to be desired. In general, the quality of CLOUD computing services is difficult to measure, not only qualitatively, but most importantly quantitatively. (Aubert, 2005).

A qualitative indicator of security, for example, in terms of colours or any other arbitrary non-numerical classification such as 'high, medium, or low', or yet another scale with 'severe, high, elevated, guarded, and low' in Figure 2 helps if no others exist, ...