What is CDN
CDN is an intelligent virtual network built on the existing network, relying on edge servers deployed everywhere. Through the load balancing, content distribution, scheduling and other functional modules of the central platform, users can obtain the required content nearby, reduce network congestion, and improve user access response speed and hit rate.
Basic Principle of CDN
The basic principle of CDN is to widely use various cache servers and distribute these cache servers In areas or networks where user access is relatively concentrated, when the user accesses the website, global load technology is used to direct the user's access to the nearest cache server that is working properly, and the cache server directly responds to the user's request.
The basic idea of CDN is to avoid bottlenecks and links on the Internet that may affect the speed and stability of data transmission as much as possible, so as to make content transmission faster and more stable. By placing node servers throughout the network to form a layer of intelligent virtual network based on the existing Internet, the CDN system can real-time analyze the network traffic and the connection and load status of each node, as well as the distance to the user and response time. and other comprehensive information to redirect the user's request to the service node closest to the user. Its purpose is to enable users to obtain the required content nearby, solve the congestion situation of the Internet network, and improve the response speed of users' access to the website.
CDN Recommendation
Youpaiyun CDN: You need to join the alliance to get 10G free traffic (cannot speed up https).
Tencent Cloud CDN: 300G free traffic for new users, 50G per month, available for half a year.
CloudFlare: Do you often hear people criticizing him in the industry? I didn't want to test it at the time, but I finally tried it, and it felt pretty good. It was not as embarrassing as they said, and it was very convenient to use. However, the CA (SSL) certificate needs to use a certificate issued by CloudFlare.
Recommended tutorial: "PHP Tutorial"
The above is the detailed content of What is CDN. For more information, please follow other related articles on the PHP Chinese website!