NIST 雲計算的定義
作者： 彼得梅和添 Grance
版本 15，09 年 7 月 10 日
美國-國家標準和技術研究院，資訊技術實驗室
注 1： 雲計算仍然一個不斷發展的範例。 它的定義使用情況下，基礎技術、 問題、 風險和福利都將由公共和私營部門精熱烈的辯論。 這些定義、 屬性和特徵將演變和隨著時間的推移而更改。
注 2： 的雲計算行業代表一個大型的生態系統的許多模型、 供應商和市場空隙。 這一定義嘗試包括所有各種雲方法。
雲計算的定義：
雲計算有利方便，一個共用的可配置池的需求對網路訪問計算的資源 （例如，網路、伺服器、存儲、應用程式和服務），可以快速設置和釋放在最少的管理工作或服務提供程式交互模型 。這種雲模式促進可用性，組成的五個基本 特徵， 三個 服務模式 與四個 部署模型。
基本特點：
按需自助服務 消費者可以單方面提供伺服器時間和網路存儲計算功能，根據需要自動無需人為交互的每個服務提供者。
廣泛的網路訪問 可通過網路功能，通過標準的機制，促進使用薄或厚的異構用戶端平臺 （例如，行動電話、 筆記型電腦和 pda） 訪問。
資源池 提供程式計算資源集中為多個消費者一個多租戶的模型使用不同的物理和虛擬資源動態分配和重新分配根據給消費者的需求。 有一種位置獨立性，客戶通常沒有控制或知識對提供資源的確切位置，但也許能夠指定在較高級別的抽象 （例如，國家、 狀態或資料中心） 的位置。 資源的示例包括存儲、 處理、 記憶體、 網路的頻寬，虛擬機器
快速的彈性 功能，可以快速和彈性調配，在某些情況下自動，給快速擴展，和快速規模的迅速釋放。 對的消費者可用的資源調配功能往往似乎是不受限制，可以在任何時間。 購買任何數量的
測量服務 雲系統自動控制和利用在某一級別的抽象適合於該類型的服務 （例如，存儲、 處理、 頻寬和活動使用者帳戶） 的計量能力優化資源的使用。 資源使用情況可以監視、 控制，和報告提供的提供者和消費者的利用服務的透明度
服務模式：
雲軟體即服務 (SaaS) 提供給消費者的能力是使用一個雲基礎架構上運行的提供程式的應用程式。 應用程式可從不同的用戶端設備通過精簡型用戶端介面如 web 流覽器 （例如，基於 web 的郵件）。 消費者不會管理或控制包括網路、 伺服器、 作業系統、 存儲，基礎雲基礎架構或甚至單個應用程式的能力，可能的例外與限制特定于使用者的應用程式的配置設置。
雲平臺作為服務 (PaaS))向消費者提供的功能是將部署到消費者創建的雲基礎架構或獲得應用程式創建使用程式設計語言和工具提供程式支援。 消費者不會管理或控制包括作業系統的系統伺服器，網路基礎雲基礎架構或存儲，但已部署的應用程式和控制可能應用程式宿主環境配置。
雲基礎架構作為(IaaS) 服務提供給消費者的能力是處理，存儲、 網路和其他基本的計算資源，消費者在哪裡能夠部署和運行任意的軟體，可以包括作業系統和應用程式的規定。 消費者不會管理或控制雲的底層基礎架構，但存儲，作業系統控制已部署的應用程式，並可能有限的控制選擇網路元件 （例如，主機防火牆）。
部署模型：
私營雲 雲基礎架構是純粹的組織運作的。 它可由組織或協力廠商和可能存在的前提或關閉前提。
社會雲 雲基礎架構由幾個組織共用，並支援一個特定的社會共用問題 (例如，特派團、 安全要求、 政策和法規遵從性考慮）。 它可由組織或協力廠商和可能存在的前提或關閉前提。
公共雲 雲基礎架構可供一般公眾或大型工業集團，由一個組織銷售雲服務。
混合雲 雲基礎架構是一個組成的兩個或更多雲 （私人、 社區，或公共），保持獨特的實體，但受一起，標準化或專有技術，使資料和應用程式可攜性 （例如，雲爆裂的雲之間的負載平衡）。
注意： 雲軟體充分利用雲模式所面向的重點是無國籍狀態、 低耦合、 模組化設計和語義的互通性服務。
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原文參考
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The NIST Definition of Cloud Computing
Authors: Peter Mell and Tim Grance
Version 15, 10-7-09
National Institute of Standards and Technology, Information Technology Laboratory
Note 1: Cloud computing is still an evolving paradigm. Its definitions, use cases, underlying technologies, issues, risks, and benefits will be refined in a spirited debate by the public and private sectors. These definitions, attributes, and characteristics will evolve and change over time.
Note 2: The cloud computing industry represents a large ecosystem of many models, vendors, and market niches. This definition attempts to encompass all of the various cloud approaches.
Definition of Cloud Computing:
Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model promotes availability and is composed of five essential characteristics, three service models, and four deployment models.
Essential Characteristics:
On-demand self-service. A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service’s provider.
Broad network access. Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).
Resource pooling. The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. There is a sense of location independence in that the customer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter). Examples of resources include storage, processing, memory, network bandwidth, and virtual machines.
Rapid elasticity. Capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.
Measured Service. Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported providing transparency for both the provider and consumer of the utilized service.
Service Models:
Cloud Software as a Service (SaaS). The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based email). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
Cloud Platform as a Service (PaaS). The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations.
Cloud Infrastructure as a Service (IaaS). The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls).
Deployment Models:
Private cloud. The cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on premise or off premise.
Community cloud. The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise.
Public cloud. The cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.
Hybrid cloud. The cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load-balancing between clouds).
Note: Cloud software takes full advantage of the cloud paradigm by being service oriented with a focus on statelessness, low coupling, modularity, and semantic interoperability.
