2022-12-06The CDN system is a technical means that can distribute website content to various nodes, that is to say, the content of a website can be distributed to various nodes around the world, and users can obtain the desired information on the nodes that are relatively close to them.
Since 1991, with the development of Internet technology and the increase of Internet users, more and more pressures have been brought to the network, and bottlenecks have gradually appeared in transmission efficiency. From 1995 to 1998, he conducted targeted research and exploration on CDN, and finally achieved important results.
Using multiple physical servers, the music, pictures, videos, applications and other resources required by users are distributed and stored all over the world, so that users can efficiently and stably obtain the required resources nearby.
Take the logistics that everyone is familiar with as an example. If you need to buy products from China’s JD.com in the United States, most of the products have been transported to the local logistics warehouse. When you receive an order, you can ship it from the nearest logistics warehouse. Logistics efficiency.
Corresponding to the CDN technology, products are the music, pictures, and video resources we need, JD.com is the resource provider such as QQ music and YouTube video, the warehouse is the CDN node, and the nearest distribution is the load balancing strategy of the CDN.
The architecture of deploying a complete CDN is divided into three layers, namely content management layer, scheduling distribution layer and edge service layer.
Content management layer: the function is to realize the centralized management and intelligent analysis of CDN network resource content, realize the presentation of resource content, the evaluation of resource quality, the analysis of cache demand, the design of scheduling scheme, the identification of hot resources, and the hit of the nearest cache.
Scheduling and distribution layer: It consists of three functional modules: control center, distribution center and traceability center. Among them, the function of the control center is to realize the scheduling and control of the edge service nodes of the CDN network; the function of the distribution center is to realize the rapid and stable transmission of the required content resources to the edge service nodes through the optimal routing path; the traceability center’s The function is to realize the cache of TOP hot content on the network, save a copy of the relevant content on the cache server, and provide redirected access to user requests. Cache nodes at all levels need to return to the source in a unified way to the resource pool.
Edge service layer: The function is based on the analysis of network TOP hotspot content, realizes distributed storage of network TOP hotspot content, provides users with access to nearby resources, supports scheduling optimization, provides sufficient resources, and realizes optimal layout optimization, to ensure the nearest hit of content resources to the greatest extent, shorten the content access time, and improve the content access efficiency.
1. CDN can increase the speed of users' access to websites. Since CDN nodes can send data requests to the source site and cache them in the server, users can obtain the cached information nearby, which can greatly increase the speed of obtaining website content.
2. CDN can reduce the load on the source site. If it is a website with a relatively large number of users, a large number of users flood in at the same time, which will cause a great burden on the corresponding speed of the website server. Through CDN technology, the content of the website Distributed to nodes in various places, this can reduce the number of users who directly access the server of the source site, and reduce the burden on the server to distribute data.
3. CDN can make room for the server to defend against external attacks. After reducing the load on the source site server, the server can focus on defending against attacks.
Since the traffic is linked to the cost, security and attack defense have always been the persistent problems of CDN. If the security is not in place, it is very likely that a wave of attacks will use up all the traffic quota, and all traffic will be invalid.
If the CDN you use is in China, you need to file for the record, because the CDN after the record will be more secure and can better accelerate the network. To a certain extent, the CDN after the record can be Prevent the invasion of viruses. But if it is a foreign CDN, you don’t need to file for the record, because there is no requirement for CDN to be filed in foreign countries. If you want to file for the CDN, you can choose relevant service providers. These service providers can help you with the record, and charge The cost is not high, but you must choose a regular network service provider.
The above is the relevant explanation about the CDN system. If you still don’t know enough about the CDN system, you can consult us online to learn more clearly.
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