Introduction
Cloud computing is a new technological model that’s transforming the world of computing (Jin et al. 2010). In this model, computation and data are operated in a cloud, which is a collection of data centers that a third party owns and maintains.
Cloud computing refers to the applications, systems, software, and hardware that are “delivered as services over the Internet” (Jin et al. 2010, p. 3).
Brief History of Cloud Computing
Cloud computing isn’t exactly a new concept. Existing structures such as adaptive computing, utility computing, and grid computing have paved the way for cloud computing (Molen 2010). ASP (application service providing) also “signifies the growth towards the provision of programs” (Molen 2010, p. 5).
Cloud computing was spurred by users’ dissatisfaction over physical computing where centralized computing failed to provide users with enough control and flexibility while distributed computing required the users to be their own system administrators, which proved to be inefficient (Simon 2010).
As the cost of computing power decreased while the cost of human resource increased, a group of computer scientists experimented with a large grid of computers that were connected through the Internet and “whose power” could “be combined for large-scale tasks when needed” (Simon 2010, p. 61). Conversely, these grids could consist of larger computing systems that were used for specialized tasks. Still, others suggested a computing utility that would enable organizations to use as much computing power as they needed and pay for it on an as-needed basis.
With the emergence of the Internet also came the concept of e-business, which became a part of every organization. This in turn led to consumers becoming familiar and knowledgeable with the advancements in technology, which they use for activities such as managing their bank accounts, watching movies, communicating with their love ones, shopping online, and searching for information. These consumer experiences drove the development of the next generation of cloud services, which provide comprehensive self-services, don’t require user training, have an intuitive user interface, and are available 24/7.
Cloud computing can then be considered the next stage in the Internet’s evolution where its beginning could be seen in the efforts of “large-scale Internet service providers” (Bhaskar, 2009) such as Amazon, Google and others to build their infrastructure. The resulting architecture was horizontally distributed and massively scaled system resources which were “abstracted as virtual IT services and managed as continuously configured, pooled resources” (Bhaskar, 2009). It provided a means through which things such as storage to business processes, computing power, and personal collaboration could be brought to users as a service.
Cloud Computing Architecture
While business entities and enterprises deploy and exploit cloud computing, researchers and academic institutes are not quite in agreement with a single meaning for the technology (Yeh 2009). Some argue that cloud computing is just another term for utility computing while others consider cloud computing to be “a revolutionary change of the computing architecture” (Yeh 2009, p. 1). However, it can be said that cloud computing has different facets, which depend on the goals that must be achieved.
There’s a vast number of things that can be done in the cloud. One of these is the access of business and productivity applications such as web authoring tools, databases, spreadsheets, emails, and word processors, which are stored in the cloud (American Screen Printing Association 2012). Cloud computing also makes it possible to create documents and wiki sites online.
According to the NIST (National Institute of Standards and Technology), cloud computing has five main characteristic features, which are measured service; rapid elasticity; location-independent resource pooling; broad network access; and on-demand self-service (Beheshti 2011).
On-demand self-service is the capability of allowing users to automatically use the available computing services such as network storage and server time whenever they need the services and without the need for human interaction. A broad network access, on the other hand, is the capability of allowing users to access the services over the cloud with the use of any connectible device such as PDAs, notebooks, desktops, and mobile phones.
Location-independent resource pooling is the capability of allowing users to dynamically use the provider’s computing resources based on their individual needs regardless of the resources’ location.
Rapid elasticity refers to the ability to provide users with elastic and rapid capabilities – even automatically in some cases. This allows users to scale in or scale out as necessary. Finally, pay-per-use or measured service refers to the capability of measuring each user’s consumed services and individually charging them for the service used.
A cloud solution’s computing architecture is the system’s structure, which consists of the “on-premise and cloud resources, services, middleware, and software components, geo-location, the externally visible properties of those, and the relationships between them” (Siemens 2010, p. 5). Only one instance of the service runs on the cloud, but it can be used by multiple client organizations and end users.
On the other hand, the different architectural layers of cloud computing are Software as a service (SaaS); Platform as a service (PaaS); and Infrastructure as a service (IaaS) (Sun Microsystems 2009).
In Software as a service, the provider offers a complete application as a service on-demand. Platform as a service, on the other hand, “encapsulates a layer of software and provides it as a service that can be used to build higher-level services” (Sun Microsystems 2009, p. 13). It is used when a platform is needed on which other applications will be run and where the platform is accessed through an API. Finally, in Infrastructure as a service, the providers feature compute and storage capabilities as services that are standardized over the network. Routers, switches, storage systems, servers, and other systems are pooled together and are provided to the users for handling workloads from high-performance computing applications to individual software components.
The delivery model for cloud services consists of four modes, namely private, public, community, and hybrid delivery (McDonald 2010). A private cloud is provisioned in a manner that enables a single entity or organization to have control over the infrastructure where the same organization has the sole benefit of utilizing the shared resources. A public cloud, on the other hand, is characterized by the existence of clients from multiple organizations who share the same infrastructure.
A community cloud is a group that’s united by a common purpose or cause, an example of which is a public-private partnership site where collaborative efforts are hosted for the improvement of airlines maintenance practices. Lastly, a hybrid cloud is one that has the combined features of the three other models, an example of which is a transportation clearing house where some information is private, some is public, and some can be shared with allied members such as travel agent sites.
Just like the cloud computing architecture, the Service Oriented Architecture (SOA) aims to combine business and IT in order to find ways for technology to serve the business’ needs (Hurwitz et al. 2009). It is a technical and business approach that is used to architect the business process as interchangeable, reusable, and black-box software components. It is a style of architecture that is used for building systems based on the interaction of “coarse grained autonomous components called services” (Rotem –Gal-Oz, n.d.) where the behavior of the services is governed by policies that are set externally from the service.
Companies benefit both from the cloud and SOA as both accord importance on the understanding of the business needs, when the business needs the service, and how cost effectively and efficiently the business can be served. However, SOA should not be confused with cloud computing.
SOA provides methods for systems integration and systems development where systems group business processes and functionality together then package them as interoperable services. It’s an infrastructure that allows the exchange of data among various applications, which participate in business processes (Software as a Service 2009). Cloud computing, on the other hand, is the Internet-based use of computer technology where resources that are dynamically scalable are provided as services over the Internet. Further, to avoid confusing either SOA or cloud computing with SaaS, SaaS is responsible for providing an application on demand where there is no implied tool, development methodology, or language associated with it.
Benefits and Limitations of Cloud Computing
There are numerous benefits that cloud computing offers. One is that it reduces cost through a combination of the use of virtualized commodity computing capacity, pay-as-you-go capacity, and capital expense avoidance, as well as reduced operational cost through the reduced requirement for internal IT personnel (Marks and Lozano 2010). It also promotes better asset utilization both in terms of the infrastructure and the people and skills. It bypasses the slow IT acquisition process as cloud computing enables the quick and easy addition of operational IT infrastructure. It also enables experimentation and the creation of more innovations. As well, it enables the organization to respond more proactively to its market.
On the other hand, one of its disadvantages is its reliability on Internet connectivity where there must be constant connection (ELC Technologies 2010). It may also pose security risks. In addition, the pay-as-you-go mode of payment results in unpredictable costs, which implies that the computing cost will vary each month.
As well, it should be considered that other non-technical challenges exist if an organization chooses to shift to a cloud computing infrastructure (Moving to the Cloud 2011). One is that it will cause a change in the organizations, which its members might resist. There may also be some government policies and regulations around cloud computing that should be considered.
Conclusion and Recommendations
Cloud computing has indeed taken over the world of computing. With the ubiquity of the Internet, people have gotten used to being able to do their computing tasks or activities at any time and at any place As such, it is only proper for organizations to also slowly adopt to this technology as it does come with a lot of benefits such as increased productivity, reduced costs, and increased flexibility.
It is then recommended that for this project, the cloud computing architecture be evaluated as part of an organization's infrastructure. Although cloud computing is not for all organizations and it does come with some limitations and disadvantages, it would still be worthwhile to conduct further analysis on the feasibility of its implementation because, if properly implemented, its benefits could far outweigh its disadvantages.
References
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