Website architecture exploration (2)-CDN basic knowledge Wang zebin

Before introducing the website architecture, we will first introduce some of the most basic and common concepts in the website architecture, so that we can better understand the following technologies related to Server Load balancer and distributed storage. First, let's talk about CDN.

1. What is CDN?
Content Delivery Network (CDN) is the Content Delivery Network or Content Delivery Network. Its main purpose is to add a new Network architecture to the existing Internet, publish the content of the website to the nearest edge of the user's network, so that the user can obtain the desired content nearby, so as to improve the response speed of the user to visit the website and improve the user experience, at the same time, the access pressure can be dispersed to distribute centralized access by users to various places. Website content providers (such as Sina, Sohu, and Netease) can use CDN to solve some headaches at the macro layer, such as high traffic and massive user concurrency.

2. CDN Composition
Content publishing network (CDN) is a strategically deployed overall system, which includes four requirements: distributed storage, Server Load balancer, network request redirection, and content management, content management and global network traffic management are the core of CDN. Based on users' proximity and server load judgment, CDN ensures that the content provides services for users' requests in an extremely efficient manner, the service that meets the user's requirements is only one Hop away from the user.
Our common content publishing mode is to place website data in one place, and then respond to access from all over the world. Most of us are considering the software deployment architecture and seldom consider the network hardware architecture. In contrast, CDN emphasizes the importance of the network in content publishing. By introducing active content management and global load balancing, CDN is fundamentally different from the traditional content publishing mode.
The content provider undertakes the content publishing services that they should not or are not doing well.

3. Industrial Chain of Internet services
Throughout the value chain of broadband services, content providers and users are located at both ends of the entire value chain, and network service providers are used in the middle to connect them. With the maturity of the Internet industry and the transformation of business models, more and more roles in this value chain are becoming increasingly subdivided, there are content operators, managed service providers, backbone network service providers, and access service providers. In this value chain, each role must work in a division of labor and perform their respective duties to provide good services to customers, resulting in a win-win situation. From the perspective of the combination of content and network, content publishing has gone through two stages: content (Application) server and IDC. The IDC boom also gave birth to the role of hosting service providers. However, IDC cannot solve the issue of effective content publishing. The content in the center of the network does not address the occupation of backbone bandwidth and the traffic order on the IP network. Therefore, pushing content to the edge of the network to provide nearby edge services for users, thus ensuring the service quality and the access order on the entire network becomes an obvious choice, this is the CDN service mode. The establishment of CDN solves the dilemma of "centralization and decentralization" for content operators, which is undoubtedly valuable for building a good Internet value chain and an indispensable optimal website acceleration service.

4. CDN service provider
ChinaCache is the largest CDN service provider in China. If you want to become a CDN service provider, I am afraid you need to deploy China Telecom, China Netcom, China tietong, and other carriers. What capabilities and background do you need. It has more than 130 service nodes worldwide, and more than 80 internal nodes in China, covering the main provinces of the country's six major networks (so-called 6-line data centers, such as major portal websites, such as Sina and Netease, all rented their services. Therefore, whether you visit these portals in the south, north, or North America, the speed is very fast. One of the main reasons is that CDN has played an effective role. Generally, small websites cannot afford this service, so slow down. You can rent a 6-line interconnected data center. If the network is wide enough, users can also endure it. If you want to continue to improve user experience, you need to make some website images deployed in representative cities, such as South China in Guangzhou and East China in Shanghai, north China can be deployed in Beijing, but content mirroring requires self-deployment and maintenance. Other Websites adopt content segmentation. For example, if sub-stations are set up in different regions and their business conditions are different, different deployment policies may be applied. CDN can be regarded as a strategy for basic network construction.

 

Wang zebin