Recently, the term “cloud technologies” and “cloud computing” can be heard more and more often. So what is “cloud technology”? Wikipedia gives the following description: “ Cloud computing (English cloud computing ) is a technology for distributed data processing in which computer resources and capacities are provided to the user as an Internet service.
The term “cloud» ( cloud is ) used as a metaphor based on the image of the Internet on a computer network diagram, or as an image of a complex infrastructure, behind which all the technical details. The widespread formal definition of cloud computing was proposed by the US National Institute of Standards and Technology:
“ Cloud computing is a model for providing on-demand convenient network access to a common pool of configurable computing resources (for example, networks, servers, storage systems, applications and services), which can be quickly identified and provided with minimal management effort or minimal intervention from the service provider ”.
What is not considered cloud computing? The first is offline computing on the local computer. Secondly, it is “utility computing”, when a service is ordered for executing particularly complex calculations or storing data arrays. Thirdly, it is collective (distributed) computing (grid computing). In practice, the boundaries between all these types of calculations are blurry enough. However, the future of cloud computing is still significantly larger than utility and distributed systems. In order to understand what a “cloud” is, it’s worth starting with the history of this issue. You need to understand: is this technology really in the category of new ideas or is this idea not so new.
1. History and key development factors
The idea of what we now call cloud computing was first voiced by Joseph Karl Robnett Liklider (JCR Licklider) in 1970, when he was responsible for the development of ARPANET (Advanced Research Projects Agency Network). Linklider’s idea was that each person would be connected to a network from which he would receive not only data, but also programs. Another scientist John McCarthy (John McCarthy) said that computing power will be provided to users as a service (service). On this, the development of cloud technologies was suspended until the 90s. A number of factors contributed to its development :
-The rapid development of the Internet, namely bandwidth. Although there were no global breakthroughs in the field of cloud technology in the early 90s, the very fact of the “acceleration” of the Internet gave impetus to the speedy development of technology.
-In 1999, Salesforce appeared . com , which provided access to its application through the site. This company was the first company to provide its software on the principle of “software as a service” ( SaaS ).
-In 2002, Amazon launched its cloud service, where users could store information and perform the necessary calculations.
In 2006, Amazon launched the Elastic Compute cloud ( EC 2) service, where users could run their own applications. Thus, Amazon EC 2 and Amazon S 3 were the first cloud computing services.
Google has contributed to the development of cloud computing with its Google Apps platform for web applications in the business sector.
The development of hardware (namely, the creation of multi-core processors and an increase in the capacity of information storage devices) and virtualization technologies (in particular, software for creating a virtual infrastructure, for example, Xen virtualization) contributed not only to the development, but also to the greater availability of cloud technologies.
2. Cloud computing now
So, once again we turn to the definition that Wikipedia gives. Cloud computing (Eng. Cloud is computing ) – the technology of distributed data processing in which computing resources and capacity available to the user as an online service. Providing the user with Internet services is a key concept. However, an Internet service should be understood not only as access to the service via the Internet, but also as access through a regular network using web technologies.
From the history and definition it can be seen that the basis for the creation and rapid development were large Internet services such as Google , Amazon , etc., as well as technical progress. Let us dwell in more detail on the impact of software and hardware development . The development of multi-core processors has led to increased productivity with the same equipment sizes, reduced equipment costs, and as a result of operating costs, reduced energy consumption of the cloud system, which for most Data Processing Centers (DPCs) is a big problem when building capacity. An increase in the capacity of information carriers, and as a result, a decrease in the cost of storing 1Mb of information, led to an unlimited increase in the volume of information stored, a decrease in the cost of servicing information storages with a significant increase in the volume of stored data. The development of multi-threaded programming technology has led to the efficient use of computing resources of multiprocessor systems, the flexible distribution of computing power of the “cloud”. The development of virtualization technology has led to the possibility of creating a virtual infrastructure, flexible scaling and building up systems, reducing the costs of organizing and maintaining systems, and the availability of virtual infrastructure via the Internet. An increase in network bandwidth has led to an increase in the speed of data exchange, lower cost of Internet traffic, and the availability of cloud technology. All these factors have led to increased competitiveness of cloud technologies in the field of Information Technology. cloud accessibility. All these factors have led to increased competitiveness of cloud technologies in the field of Information Technology. cloud accessibility. All these factors have led to increased competitiveness of cloud technologies in the field of Information Technology.
Like any technology, cloud technology has both its advantages and disadvantages. The main advantages include the following :
Accessibility – “clouds” are accessible to everyone and everywhere where there is Internet and from any device where there is a browser.
Low cost – reduced maintenance costs (use of virtualization technologies), payment only for the actual use of cloud resources by the user (allows you to save on the purchase and licensing of software), rent a “cloud”, the development of the hardware of computing systems.
Flexibility – unlimited computing resources (virtualization).
Reliability – specially equipped data centers have additional power sources, regular data backup, high bandwidth of the Internet channel, and resistance to DDOS attacks.
Security – a high level of security with a competent organization, however, if neglected, the effect may be the opposite.
Large computing power – the user can use all the computing power available in the “cloud”. With all its advantages, cloud technologies have a number of serious drawbacks :
Permanent connection to the network – to work with the “cloud” you need a constant connection to the network.
Software – the user can access only the software that is in the “cloud”, and the user can not configure applications for themselves.
Confidentiality – There is currently no technology that provides 100% data privacy. Reliability – loss of information in the “cloud” means the impossibility of its recovery.
Security – although the “cloud” is a fairly reliable system, but in the case of an intruder, an enormous amount of data will be available to it.
High cost of equipment – significant material resources are needed to create your own “cloud”. Cloud technologies have an extensive range of services that a user can use to solve specific problems . Below are the main types of services provided by cloud systems   .
Everything as a Service ( Everything as with the a the Service ) – this approach the user will have access to everything from hardware and software to business process management, including interaction between users. All that is required of the user is access to the Internet.
Infrastructure as a Service ( Infrastructure as with the a the Service ) – available only to the user computer infrastructure (usually a virtual platform, related to the network), which he adjusts to fit your needs.
Platform as a service ( Platform as with the a the Service ) – user computing platform is available with the operating system and possibly software.
Software as a service ( Software as with the a the Service ) – the user can use the software deployed on a remote server, which is accessed via the Internet. This type of service implies payment only for the actual use of the software, and all issues related to licensing and updating the software lie with the provider of this service.
Hardware as a Service ( Software as a Service ) – the user is provided with equipment on a rental basis, which he can use for his own purposes. This type of service is very similar to the services “Infrastructure as a service” and “Platform as a service”, except that the user has access only to the equipment on which he installs all the software.
Workplace as a Service ( the Workplace as with the a the Service ) – the company arranges jobs for their employees by installing and configuring all of the software.
Data as a Service ( the Data as with the a the Service ) – user is provided with enough disk space to store information.
Security as a Service ( Security as with the a the Service ) – allows users to deploy products to ensure the safety of web technologies, correspondence, local system.
Cloud services that provide certain types of services, in turn, are divided into three categories: public, private and hybrid  .
Public “cloud” is an IT infrastructure used by many companies and services. At the same time, users cannot manage and maintain this “cloud”, all responsibility on these issues lies with the owner of the “cloud”. Any company, as well as any individual user, can become a subscriber. Clouds of this type offer an easy and affordable way to deploy websites or business systems with great scalability that are not available in other types of clouds. Examples : Amazon EC2 and Simple Storage Service (S3) online services , Google Apps / Docs, Salesforce.com, Microsoft Office Web.
Private “cloud” – a secure IT infrastructure controlled and operated by one company. The subscriber can manage the “cloud” independently, or entrust this to an external contractor. The infrastructure itself can be located on the premises of the company itself, or with an external operator, or partially with the operator and partially with the company.
Hybrid “cloud” – IT infrastructure that uses the best aspects of public and private types of “clouds”. This type is mainly used when an organization has seasonal periods of activity. Those. part of the capacity of the private “cloud” is transferred to the public “cloud” if it does not cope with current tasks. In addition, access to company resources is organized through a public “cloud”.
3. Current trends and development prospects
Today, cloud computing is something that almost everyone uses daily. Having found on the Internet a suitable service for daily use, most of which are free or relatively cheap, the user eliminates the need to buy newer computers to ensure high performance, from the difficulties in setting up complex systems and buying expensive software packages.
Cloud technologies are developing rapidly and cover more and more areas of activity. For example, mail clients. Until recently, most users had one or another email client for receiving, sending and processing email, now the role of the email client is performed by Gmail, and such services as Yahoomail, Webmail, Hotmail and others are flexible and convenient . Moreover, recently, among fairly large world portals, there has been a tendency to transfer mail systems to ready-made sites like Gmail  . In this case, the user initially receives a familiar interface.
A similar situation is observed with office suites. Online editors Zoho Writer or Google Docs can perform the same functions as regular office suites, moreover, many such editors can not only format and save documents, but also import and export them to other formats . Editgrid or Google table editors can easily replace Exel . And this is not a complete list of all available services available to all those who have access to the Internet.
You can see that the “clouds” have gained popularity. In addition, the technology itself is constantly being improved. According to European experts, initially it is necessary to develop methods for regulating legal issues related to aspects of the functioning of systems, as well as methods for planning and analyzing effectiveness .
One of the key features is the ability to remotely access services, however, the question arises of data storage. Moreover, the stored information may be subject to the laws of the country in which the physical storage is located (even worse if distributed storage is used) . In this regard, experts urge states to start thinking about solving the legal aspects of the work of cloud systems. Another important development factor is the creation of economic models for the use of IT services. In addition to legal and economic aspects, there are a number of technical problems that require close attention. The most important is considered a security problem. Disputes on this topic have been ongoing for a long time, but so far there is no consensus that would suit everyone. In addition, it is necessary to develop a system management system,
In the most general sense, based on the foregoing, cloud technologies can be called technologies that allow client workstations to use external computing resources, storage capacities, etc.
Indeed, cloud technologies provide almost limitless possibilities thanks to their services, from simple storage of information to the provision of complex, secure IT infrastructures. In addition to providing computing power to end users, cloud technologies provide new jobs for IT professionals who are able to configure and maintain “clouds”. And since the technologies themselves are quite young, research is continuing on the possibility of their application in various areas of life.
The main difficulty in the development of cloud technologies is not to solve technical issues, but to choose a mutually beneficial development path. That is why many commercial and government organizations participate in the discussion of concepts and choose strategies for the development of IT systems.