1. The concept of cloud computing
1. 1 NIST draft definition of cloud computing
On April 24th, 2009, NIST experts gave a draft definition of cloud computing, and summarized its five characteristics, three service modes and four deployment modes.
1. 1. 1 cloud computing definition
Cloud computing is a pay-per-use model, which provides available, convenient and on-demand network access and access to a configurable pool of computing resources (including networks, servers, storage, application software and services), which can be provided quickly with little management work or little interaction with service providers. Cloud computing mode improves usability. The cloud computing model consists of five main features, three service models and four deployment models.
Main features of 1. 1.2
(1) Self-service on demand. Consumers can unilaterally deploy processing power on demand, such as server time and network storage, without manual interaction with each service provider.
(2) Access through the network. Various capabilities can be obtained through the Internet and accessed in a standard way, thus being widely used by many thin clients or rich clients (such as mobile phones, laptops, PDA, etc.). ).
(3) Location-independent resource pool. The computing resources of suppliers are centralized to serve all customers by multi-user leasing, and different physical and virtual resources can be dynamically allocated and redistributed according to customer needs. Customers often have no control or knowledge of the exact location of resources. These resources include storage, processors, memory, network bandwidth and virtual machines.
(4) Fast scalability. It can provide capacity quickly and flexibly, expand quickly, release quickly and realize rapid contraction. For customers, the resources that can be rented seem infinite, and any number of resources can be purchased at any time.
(5) Pay by use. Ability charge is a one-time payment based on measurement or advertisement to promote the optimal utilization of resources. Such as calculating the consumption of storage, bandwidth and computing resources, and charging according to the actual usage of users on a monthly basis. The cloud within the organization can calculate the expenses between departments, but it is not necessarily real money.
Note: Cloud computing software services focus on boundlessness, low coupling, modularity and semantic interoperability, and make full use of the advantages of cloud computing mode.
1. 1.3 service mode
(1) Cloud computing software as a service. The capabilities provided to customers are applications run by service providers on cloud computing infrastructure, which can be accessed on various client devices through thin client interfaces (such as browsers). Consumers don't need to manage or control the functions of the underlying cloud computing infrastructure, network, server, operating system, storage or even a single application, except for some limited application software configuration settings that customers can customize.
(2) Cloud computing platform is a service. The ability provided to consumers is to deploy customers to cloud computing infrastructure using development languages and tools provided by vendors (such as Java, python,. Net). Customers do not need to manage or control the underlying cloud infrastructure, networks, servers, operating systems and storage, but consumers can control the deployed applications and possibly the configuration of the application hosting environment.
(3) Cloud infrastructure as a service. The ability provided to consumers is to rent processing power, storage, network and other basic computing resources, and users can deploy and run any software, including operating systems and applications. Consumers do not manage or control the underlying cloud computing infrastructure, but can control the operating system, stored and deployed applications, and may choose network components (such as firewalls and load balancers).
Fourth, the deployment mode
(1) private cloud. Cloud infrastructure is owned or leased by a single organization and operated only for that organization.
(2) Community cloud. Infrastructure is enjoyed by some organizations and serves communities with common concerns (for example, tasks, security requirements, policies and guiding principles, etc.). ).
(3) Public cloud. Infrastructure is owned by an organization that sells cloud computing services to the public or various industrial groups.
(4) Hybrid clouds. Infrastructure consists of two or more clouds (internal cloud, community cloud or public cloud). Each cloud remains independent, but they are combined with standard or proprietary technologies that have portability of data and applications (for example, it can be used to handle sudden loads).
1.2 The characteristics of the cloud computing field are:
(1) At present, the major cloud computing vendors in the market are some IT giants, and they are all in the stage of attacking the city.
(2) The standard has not yet been formed. Basically, we have different opinions on the issue of standards.
At present, cloud computing products and services on the market are very different, and users don't know how to start when choosing.