Introduction: Key Characteristics of Cloud Computing
The information technology (IT) industry is probably the most fast-evolving and life-changing sphere operating in the modern world. With the rapid development of the Internet and IT opportunities, users are receiving more and more possibilities for finding, sharing, and storing data. Cloud computing (CC) belongs to the most recent and convenient aspects of IT. A cloud is a set of technologies that can be reached using a web portal (Fox and Hao 453).
Whereas a traditional web server allows executing server-side scripts, the cloud enables users to process functions related to productivity, accounting, communications, and software. Hence, the required software obtains additional layers that web servers have to operate (Fox and Hao 453). Most commonly, the accomplishment of such software is relocated to other computers. CC is defined as remote access to a cloud processing work.
The popularity of CC is increasing on a daily basis both among individual users and organizations. Due to an unprecedented enhancement in the sphere of communication, the use of CC is escalating (Sengupta 209). CC offers a variety of benefits and opportunities, such as saving time, eliminating risks, avoiding unneeded investments, and cutting down expenses (Ghazizadeh and Olariu 438). There are several types of CC deployment and service models, each one offering a specialized set of options.
Cloud Computing Deployment Models
In the public cloud deployment model, service providers’ offers are available to any public user who has signed up for the services on demand. The public cloud enables sharing of all the resources among all the users (Aldribi et al. 337). Customers can use only those resources which they need, and to the extent they require. Because of a large pool of users, the public cloud may face such risks as regulatory compliance and security (Aldribi et al. 337).
The main advantage of public cloud deployment is the possibility to save costs. Furthermore, since the users do not have to take care of installing and running their own servers, their productivity increases (Surianarayanan and Chelliah 42). At the same time, public clouds pose some threats, such as security issues due to multi-tenancy (Surianarayanan and Chelliah 43). However, the advantages outweigh the disadvantages of public cloud computing.
In private cloud deployment, the ownership and management of the cloud belongs to a single organization providing its services to customers over a secure self-service portal. Despite being more expensive than public clouds, private clouds have a much higher level of security (Aldribi et al. 338). Private clouds can be deployed in two ways: either within the involved organization or a third-party provider (Surianarayanan and Chelliah 44).
With the help of the private cloud, organizations can automate their processes and create a self-service interface enabling the developers to provide services upon request. Another benefit of the private cloud is the variability of resources available, such as storage, platforms, compute servers, and networks (Surianarayanan and Chelliah 44). The private cloud deployment allows enhancing the efficiency of the environment and creates security measures crafted specifically for each organization.
The major purpose of any business is to remain connected with its clients, workers, and partners. A community cloud can join all of these separate stakeholders into a single community (Surianarayanan and Chelliah 48). The community cloud service model enables a cloud computing service to a restricted number of organizations with common privacy, security, and management settings. Hence, the community cloud deployment presupposes the work of several organizations on the same platform on the condition that their regulation and security policies coincide (Surianarayanan and Chelliah 48).
The main benefit of the community cloud is the low cost of setting it up due to the possibility to share costs among all the users. Other advantages include a simplified collaboration on projects and hosting in a third-party facility (Surianarayanan and Chelliah 48). A limitation of the community cloud is the need to share certain potentially sensitive data with other stakeholders.
A hybrid cloud combines the features of private and public clouds through proprietary or standardized technology, allowing for the portability of information and application. To use the opportunity of accessing unlimited computational resources, companies lean to hosting their sensitive data and services in a private cloud, and other services – in a public one (Surianarayanan and Chelliah 46).
Hybrid clouds enable organizations to overcome the difficulty of experiencing unexpected load conditions due to the opportunity of a dynamic increase in scalability. The main positive outcomes of connecting the features of private and public clouds include integration, data localization, portability, security, and operational visibility (Surianarayanan and Chelliah 46-47). Hence, the hybrid cloud successfully combines the advantages of private and public clouds, offering the most positive outcomes for customers.
Public cloud service providers tend to offer a variety of services to different users. Meanwhile, an organization or a single user may require a combination of services, such as a PaaS and an IaaS. In such a case, the customer needs to utilize the services of a multi-cloud (Surianarayanan and Chelliah 49). Multi-clouds enable users to reach multiple business aims by mixing at least two public clouds. Multi-cloud deployment allows managing and reimbursing for cloud services in a way that is most convenient and profitable for the company (Surianarayanan and Chelliah 49). The benefits of multi-clouds include superior security, low latency, and high autonomy.
Cloud Computing Service Models
Infrastructure as a Service (IaaS)
IaaS offers servers, networks, virtual machines, and storage to users. Customers can reach the infrastructure needed for managing their applications and personal operating systems (Aldribi et al. 336). At the same time, they do not have control over the infrastructure, so they can only run virtual machines with the operating systems suggested by CC. One of the best examples of IaaS is Amazon Web Services, the system letting Amazon provide computing resources to users via the Elastic Compute Cloud service with the help of Elastic Book Store and Simple Storage Service (Ghazizadeh and Olariu 438).
Advantages of IaaS include the reduction of the upfront cost of arranging and running an on-site data center and prompt reaction to changing business requirements as an effect of cloud elasticity (Surianarayanan and Chelliah 52). Additionally, IaaS allows for the rapid deployment of new infrastructure and disaster recovery.
Platform as a Service (PaaS)
PaaS offers its users not only the software platform for applications but also the hardware structure. The products available using PaaS include app servers, web, and database servers, as well as programming environments (Surianarayanan and Chelliah 52). The most popular PaaS providers are RedHat OpenShift, Microsoft Azure, and Google App Engine. Microsoft Azure provides a platform for both open-source tools and Windows-based.
Meanwhile, RedHat OpenShift and Google App Engine offer a platform for the generation of web apps established on open-source environments (Surianarayanan and Chelliah 53). The main advantage of PaaS is the possibility to reduce expenditures on software licensing and software maintenance and updates. Other benefits include reduced coding time, constant multi-platform support, and life-cycle management support for deploying and updating web apps within the integrated settings.
Software as a Service (SaaS)
Finally, SaaS offers an application that a user can utilize as a service on demand using a subscription. Due to its “pay-as-you-go” option, SaaS enables customers to use the necessary software whenever they need it, hence avoiding the complicated installation process and saving costs considerably (Ghazizadeh and Olariu 438). SaaS users only have to log in and use the application that is “run on the provider’s infrastructures” (Surianarayanan and Chelliah 53). The most popular examples of SaaS are GoogleAppEngine, Workday’s ERP, IBM, and Salesforce’s CRM (Ghazizadeh and Olariu 438; Surianarayanan and Chelliah 55).
The major advantages of using SaaS include saving costs on installing and maintenance processes, enabling users to receive remote access to software, and allowing customers to use the applications at any time (Surianarayanan and Chelliah 56). What is more, users only have to pay for the actual usage of the app rather than make regular payments and leave the software untouched most of the time.
Cloud computing is a highly convenient approach to storing and managing one’s data without having to spend much money on software installation and maintenance. Depending on the customer’s needs, one can choose between a private, public, community, and hybrid cloud deployment. Furthermore, if the organization requires a combination of several clouds, it can utilize the benefits of a multi-cloud. With the rapid development of IT and its growing role in all the spheres of people’s lives, cloud computing has occupied an essential place in the technology services’ options.
Aldribi, Abdulaziz, et al. “Data Sources and Datasets for Cloud Intrusion Detection Modeling and Evaluation.” Cloud Computing for Optimization: Foundations, Applications, and Challenges, edited by Bhabani Shankar Prasad Mishra et al., Springer, 2018, pp. 333-366.
Fox, Richard, and Wei Hao. Internet Infrastructure: Networking, Web Services, and Cloud Computing. CRC Press, 2018.
Ghazizadeh, Aida, and Stephan Olariu. “Vehicular Clouds: A Survey and Future Directions.” Cloud Computing for Optimization: Foundations, Applications, and Challenges, edited by Bhabani Shankar Prasad Mishra et al., Springer, 2018, pp. 435-463.
Sengupta, Nandita. “Security and Privacy at Cloud System.” Cloud Computing for Optimization: Foundations, Applications, and Challenges, edited by Bhabani Shankar Prasad Mishra et al., Springer, 2018, pp. 207-234.
Surianarayanan, Chellammal, and Pethuru Raj Chelliah. Essentials of Cloud Computing: A Holistic Perspective. Springer, 2019.