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.
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.
1.2 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
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.
2.2 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
2.3 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.
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).
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.
3.3 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?
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.
4.2 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.
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.
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!