Cloud Computing
Abstract
Cloud computing, as a hot technology in IT industry, has always been a hot issue in society, and now it has been continuously developed and widely used. Based on the definition and principle, characteristics, service model and core technology of cloud computing, this paper discusses the application and security of cloud computing and the development trend of cloud computing.
Key words: cloud computing, service mode, core technology, cloud application, cloud security.
概要
云计算作为当前IT行业的热门技术，它一直是社会里的热点问题，而如今得到不断发展和广泛应用。本文基于云计算定义和原理、特点、服务模式和核心技术，并且围绕云计算的应用和安全、云计算的发展趋势来探讨一下这个云计算。
关键词：云计算，服务模式，核心技术，云应用，云安全。
1. Overview of cloud computing
1.1 Definition of cloud computing
Wikipedia defines cloud computing as an Internet-based computing method in which shared software and hardware resources and information can be provided to various computer terminals and other devices as required, using the computer infrastructure provided by the service provider for computing and resources. To put it simply, it brings together a number of computer resources and application services (application, such as browsing web pages and downloading movies), which may be formed by countless data centers connected over the Internet, resulting in so-called cloud computing.
1. 云计算概述
1.1云计算定义
维基百科中给出定义：云计算是一种基于互联网的计算方式，通过这种方式，共享的软硬件资源和信息可以按需求提供给计算机各种终端和其他设备，使用服务商提供的电脑基建作计算和资源。简单来说就是将诸多的计算机资源和应用服务（application，例如浏览网页，下载电影）集中在一起，而这些计算机资源可能由多个无数个数据中心通过互联网相连形成的，从而形成了所谓的云计算。
1.2 Basic features of cloud computing
The idea behind cloud computing is simple. It's simply about pooling computer resources and putting them on the web. But the implementation of cloud computing is more complex. For example, if you just buy a server and set up an FTP server in your company, you can share resources among your colleagues in your company. But if it's singles' day, Taobao's shopping festival, and billions of people around the world visit Alibaba's Taobao site, dozens of petabytes (1PB=1024TB=1024×1024GB) of page views in a single day, and hundreds of gigabytes of traffic per second, this is not a question that a few servers can solve. At this time, we need to design a reliable cloud computing system to meet the requirements of the smooth operation of the business. And this cloud computing system has to meet the requirements of super capacity, super concurrency (simultaneous access), super speed and super security. The specific basic characteristics of cloud computing can be roughly shown in figure 1:
Figure1 the basic characteristics of cloud computing
1.2、云计算基本特征
云计算的原理是简单的，简单来说就是把计算机资源集中起来，放在网络上。但是云计算的实现方式就比较复杂了。例如，如果你只是买个服务器然后在公司搭建FTP服务器，能够实现公司内同事之间的资源共享，这个当然是很简单的。但如果是“双11”的淘宝购物节，全球几十亿用户访问阿里巴巴的淘宝网站，单日几十PB（1PB=1024TB=1024×1024GB）的访问量，每秒几百GB的流量，这个就不是几台服务器就能解决的了。这时就需要设计一个靠谱的云计算系统，才能满足业务平稳运行的要求。而这个云计算系统得符合超大容量、超高并发（同时访问）、超快速度、超强安全的要求。而云计算具体基本特征可大致如图1所示：
图1 云计算基本特征
2. Cloud service mode
2.1 Concept of cloud services
We refer to the software services provided as "cloud services", which means that one or more software functions can be accessed over the Internet using a standard interface. Cloud services are services that can be IT, software, internet-related, or other services that are available in an on-demand, scalable manner over the web. It means that computing power can also flow as a commodity over the Internet.
2 云服务模式
2.1.云服务概念
我们把所提供的软件服务称为“云服务”，云服务是指可以在互联网上使用一种标准接口来访问一个或多个软件功能。它指通过网络以按需、易扩展的方式获得所需服务，这种服务可以是IT、软件、互联网相关，也可是其他服务。它意味着计算能力也可作为一种商品通过互联网进行流通。
2.2 Main forms of cloud service deployment
According to deployment, cloud computing can be divided into four cloud service deployment models: public cloud, private cloud, community cloud and mixed cloud. Different deployment models also have different technical requirements on the infrastructure. Therefore, it is necessary to understand the differences between these cloud computing deployment modes. The specific four cloud computing deployment modes are shown in figure 2:
Figure2 Cloud computing deployment modes
2.2云服务部署的主要形式
云计算按照部署可分为公有云、私有云、社区云和混合云四种云服务部署模型，不同的部署模型对基础架构也有着不同的技术要求，所有很有必要了解这几种云计算部署模式之间的不同。具体的这四种云计算部署模式如图2所示：
图2 云计算部署模式
2.3 Architecture level of cloud services
Cloud service architecture provides users with various levels of services at various levels, which is the typical cloud computing service system generally accepted by the industry —— infrastructure services (IaaS), platforms and services (PaaS), and software and services (SaaS). The specific hierarchy diagram of cloud architecture is shown in figure 3:
Figure3 hierarchy diagram of cloud architecture
We can understand these three levels in this way: the IaaS layer is the lowest hardware resource, including CPU (computing resource), hard disk (storage resource), network card (network resource) and so on; the PaaS layer is slightly higher, which is equivalent to that the customer does not intend to use CPU, hard disk and network card directly. It is hoped that the service provider will install the operating system (such as Windows、Linux) and provide the database system software to the customer for use. Finally, the SaaS layer can understand that the service provider should install the basic software such as operating system, and install the specific application software (such as ftp client, video software), and finally provide it to the customer for use.
2.3云服务架构层次
云服务架构各个层次为用户提供各种级别的服务，即业界普遍认同的典型云计算服务体系——基础设施服务（IaaS）、平台及服务（PaaS）和软件及服务（SaaS）。具体的云架构层次示意图如图3所示：
图3 云计算架构层次图
我们可以这么理解这三种层次：IaaS层是最底层的硬件资源，主要包括CPU（计算资源），硬盘（存储资源），还有网卡（网络资源）等；PaaS层稍微高级点，相当于客户不打算直接使用CPU、硬盘和网卡，希望服务提供商把操作系统（例如Windows、Linux）装好，把数据库系统软件也装好之后提供给客户使用；最后的SaaS层可以这样理解，服务提供商要在装好操作系统等基本软件的前提下，并把具体的应用软件（例如ftp客户端、视频软件）装好，最后在提供给客户使用。
3. Core technology of cloud computing
3.1 Data storage of cloud computing
Cloud computing is a new computing model, which is mainly characterized by the system has a large data set and provides services to users based on the data set. In order to ensure high availability, reliability and economy, it adopts distributed storage to store data, which can store multiple copies for the same data. Therefore, the data storage technology of cloud computing must have the characteristics of high throughput and high transfer rate. For example, typical cloud computing data storage technologies include Google non-open source GFS (Google File System) and Hadoop HDFS (Hadoop Distributed File System).
3、云计算的核心技术
3.1云计算的数据存储
云计算是一种新型的计算模式，它的主要特征是系统拥有大规模数据集并且基于数据集向用户提供服务。为了保证高可用、高可靠和经济性，它采用了分布式存储的方式来存储数据，这种数据存储可冗余可为同一份数据存储多个副本。因而云计算的数据存储技术必须具有高吞吐率和高传输率的特点。例如典型的云计算数据存储技术有谷歌非开源的GFS（Google File System）及Hadoop的HDFS（Hadoop Distributed File System）
3.2 Virtualization technology
Virtualization is a broad term, meaning that the computing elements run on a virtualized basis rather than on a real basis, a solution to simplify management and optimize resources. As a popular point, we use virtualization technology to uniformly manage physical resources. Virtualization is the foundation of cloud computing. In fact, virtualization is a so-called virtual machine running multiple "virtual server" on one physical server. Virtual machines appear to be independent servers, but they actually share the physical server's CPU, memory, hard disk, network card, and other resources. The physical machine functions as a host, a virtual machine as a client, and the middle of them requires a ‘supervisor’ - hypervisor to complete the work of physical resource virtualization. Common Hypervisor, such as VMware, KVM, Xen, Virtual Box.
3.2 虚拟化技术
虚拟化是广义上的术语，是指计算元件在虚拟化的基础上而不是在真实的基础上运行，是一个为了简化管理，优化资源的解决方案。说的通俗点，我们使用虚拟化技术对物理资源进行统一管理。虚拟化是云计算的基础。实际上，虚拟化就是在一台物理服务器上运行多台“虚拟服务器”，就是所谓的虚拟机。表面上看，虚拟机都是独立的服务器，但实际上它们共享物理服务器的CPU、内存、硬盘、网卡等资源。物理机作为宿主机（host），虚拟机作为客户机，而它们中间则需要一个“监督者”——Hypervisor来完成物理资源虚拟化的工作。常见的Hypervisor如VMware、KVM、Xen、Virtual Box。
3.3 Cloud platform management technology
Cloud platform management is a console running in cloud computing services, an important tool for cloud computing services monitoring, management, analysis and optimization, and an information architecture supporting and guaranteeing cloud computing services. The schematic diagram of its cloud management platform is shown in figure4:
Figure4 Schematic diagram of cloud management platform
To put it simply, we provide the ability to virtualize and simulate the running of CPU through Hypervisor software, but its user interaction is not friendly, so in order to manage virtual machine resources more conveniently and effectively, we need a cloud management platform such as OpenStack. This cloud management platform can provide users with a graphical interface based on the web. Isn't that more friendly than the command line?
3.3 云平台管理技术
云平台管理是运行在云计算服务的控制台，是云计算服务监控、管理、分析和优化云计算服务的重要工具，是支撑和保障云计算服务的信息化架构。其云管理平台示意图如图4所示:
图4 云管理平台示意图
简单来说，我们通过Hypervisor软件提供了虚拟化的能力，模拟CPU的运行，但是它的用户交互性并不友好，于是为了更加方便有效的管理虚拟机资源，就需要类似于OpenStack这样的云管理平台。这种云管理平台可以基于web向用户提供图形化界面操作，这样是不是要比命令行更加友好呢？
4. Application and security of cloud computing
4.1 Application of cloud computing
Cloud application is a subset of cloud computing and the embodiment of cloud computing technology in the application layer. Cloud Applications work by turning traditional software from a "local-install" to a "pay-as-you-go" service. It connects to and operates a cluster of remote servers via the Internet or local area network (LAN), and finally performs business and operation. Cloud applications can reduce IT costs and improve work efficiency. Typical cloud applications include cloud Internet, cloud education, cloud games and cloud social networking.
4、云计算的应用和安全
4.1云计算的应用
云应用是云计算的子集，是云计算技术在应用层的体现。云应用的工作原理是把传统软件“本地安装”的使用方式变为“即取即用”的服务，通过互联网或者局域网连接并操控远程服务器集群以完成业务和运算。云应用可以降低IT成本和提高工作效率，典型的云应用如云物联、云教育、云游戏和云社交等。
4.2 Security of cloud computing
Cloud computing market plays a positive role in promoting cloud security. Where there is cloud computing, there is cloud security. Huge cloud computing customers also have high requirements for cloud security, so cloud computing should first solve the trusted problem, rely on trusted technology to solve the reliability of data storage; according to the service QoS guarantee technology, solve the quality of service; comprehensive use of encryption, digital signature, authentication, authorization and other security technologies to build a complete cloud security system.
4.2云计算的安全
云计算的市场对云安全的积极的促进作用，哪里有云计算，哪里就有云安全。庞大的云计算使用客户对云安全的要求也特别高，所以云计算首先要解决可信问题，依靠可信技术来解决数据存储的可靠性；依据服务QoS保障技术，解决服务质量；综合利用加密、数字签名、认证、授权等安全技术，构建完整的云安全体系。
5. Development trend of cloud computing
Since August 9, 2006, when Google CEO Eric Schmidt first proposed the concept of cloud computing at the search engine conference, it has been nearly more than a decade since its development, and its technology is actually approaching maturity. In real life, cloud computing really brings great convenience to our life, which promotes the development and progress of the entire information industry. Today's education industry, communication industry, medical industry and other industries have begun to have the specific application of cloud computing, and began to slowly spread. The Chinese government also attaches great importance to the development of cloud computing, and the awareness of large enterprises on cloud computing is also constantly improving. Many companies, such as Huawei, Alibaba and Tencent, also provide their own cloud solutions. Moreover, according to the market survey of cloud computing in recent years, the development of cloud computing is still in a growing trend. Therefore, I believe that the future of cloud computing will continue to develop, its technology will be more and more exquisite, it will spread to every corner of the world.
5、云计算发展趋势
自2006年8月9号，Google的CEO埃里克施密特在搜索引擎大会上首次提出云计算的概念，到现在它发展已经差不多十几年的时间了，它的技术其实已经趋近成熟了。而在实际生活中，云计算确实给我们的生活带来了极大的便利，它推动了整个信息产业的发展及进步。当今的教育行业、通信行业、医疗行业等都开始有了云计算的具体应用，并且开始慢慢普及。中国政府也对云计算的发展非常重视，并且各大型企业对云计算的认知也在不断的提高，很多公司如华为、阿里巴巴和腾讯也各自提供他们的云解决方案。而且根据近几年云计算的市场行情调查显示，云计算发展还在处于一个增长的趋势。所以我相信云计算的未来还会在连续发展着，它的技术会越来越精湛，它将普及到世界的每个角落。
Conclusion
With the continuous development of global information, cloud computing is the development trend of the entire IT industry. The data development direction of contemporary IT industry tends to be quantitative, diversified and centralized, so cloud storage and cloud security are particularly important. In addition, cloud computing is an indispensable technology in emerging technologies such as big data, Internet of things, blockchain and artificial intelligence. There is a close connection between them, so cloud computing is the foundation. Therefore, cloud computing conforms to the development of The Times, makes the pace of future development faster, and makes resources more fully used and Shared. We will also usher in a more transparent, more convenient and adequate access to information cloud era!
结束语
随着全球信息化的不断发展，云计算是整个IT产业发展的趋势。 当代IT行业的数据发展方向趋向于海量化、多元化、集中化，因而云存储和云安全也显得格外重要。并且云计算是当前大数据、物联网、区块链和人工智能等新兴技术中不可或缺的一门技术，它们之间存在着紧密的联系，可以说云计算是基础。所以说云计算，它顺应了时代的发展，它使未来发展的脚步更快，使资源得到更加充分的使用和共享。我们也将迎来一个更加透明的，信息获取更加便捷充足的云时代！
