A network that provides resources is called a "cloud". The resources in the "cloud" can be infinitely expanded by users, and can be obtained at any time, used on demand, expanded at any time, and paid according to use. This feature is often referred to as using IT infrastructure such as water and electricity.
2. Generalized cloud computing
This service can be related to IT, software and Internet, or any other service.
Generally speaking, cloud computing can be regarded as a commercial evolution version of grid computing. As early as 2002, China and Liu Peng put forward the concept of computing pool to solve the practical problems of traditional grid computing thought: "Connect high-performance computers scattered all over the country with high-speed networks, organically bind them together with specially designed middleware software, accept computing requests from scientists all over the world with Web interfaces, and assign them to appropriate nodes for operation. Computing pool can greatly improve the quality of service and resource utilization, while avoiding the inefficiency and complexity caused by dividing applications across nodes, and can meet the actual needs under current conditions. " If the "high-performance computer" in this paper is replaced by "server cluster" and the "scientific worker" is replaced by "business user", it will be very close to the current cloud computing.
Cloud computing has the following characteristics:
(1) Very large scale. "Cloud Computing Management System [5]" has a considerable scale. Google Cloud Computing has more than 1 10,000 servers, and Amazon, IBM, Microsoft, Yahoo and other "clouds" all have hundreds of thousands of servers. Enterprise private clouds generally have hundreds of servers. "Cloud" can give users unprecedented computing power.
(2) Virtualization. Cloud computing supports users to obtain application services at any place and using various terminals. The requested resources come from the "cloud" rather than a fixed tangible entity. The application runs somewhere in the cloud, but in fact, users don't need to know or worry about the specific location where the application runs. All we need is a notebook or a mobile phone, and we can achieve everything we need through network services, even such tasks as supercomputing.
(3) High reliability. "Cloud" adopts measures such as fault tolerance of multiple copies of data and isomorphic interchange of computing nodes to ensure high reliability of services. Using cloud computing is more reliable than using local computers.
(4) universality. Cloud computing is not specific to a particular application. With the support of cloud, ever-changing applications can be constructed, and the same cloud can support different applications at the same time.
(5) High scalability. The scale of the "cloud" can be dynamically expanded to meet the growing needs of applications and users.
(6) On-demand service. "Cloud" is a huge resource pool, which you can buy on demand; Clouds can be charged like tap water, electricity and gas.
(7) extremely cheap. Because the special fault-tolerant measures of "cloud" can use extremely cheap nodes to form a cloud, the automatic centralized management of "cloud" makes a large number of enterprises not have to bear the increasingly high cost of data center management, and the universality of "cloud" greatly improves the utilization rate of resources compared with the traditional system, so users can fully enjoy the low-cost advantage of "cloud", and often it takes only a few hundred yuan and a few days to complete tasks that used to take tens of thousands of yuan and months.
Cloud computing can completely change people's future lives, but at the same time, we should pay attention to environmental issues, so as to truly contribute to human progress, rather than simply upgrading technology.
(8) Potential danger: Cloud computing services must provide storage services in addition to computing services. However, cloud computing services are currently monopolized by private institutions (enterprises), and they can only provide commercial credit. For government agencies and commercial organizations (especially commercial organizations with sensitive data like banks), it is necessary to be cautious when choosing cloud computing services. Once commercial users use cloud computing services provided by private organizations on a large scale, no matter how strong their technical advantages are, these private organizations will inevitably seize the whole society with the importance of "data (information)". For the information society, "information" is crucial. On the other hand, the data in cloud computing is confidential to users other than the data owner, but it is really not a secret to commercial organizations that provide cloud computing. It's like ordinary people can't monitor other people's phones, but inside a telecom company, they can monitor any phone at any time. All these potential dangers are important premises that commercial organizations and government agencies have to consider when choosing cloud computing services, especially those provided by foreign organizations. I think the prospect is very good. For example, in the future, computers can do anything as long as they have access to the Internet, and processors can generally handle everything like online antivirus, but there are security problems. Now Microsoft, Google and IBM are all doing it.