I. What is CDN?

The full name of CDN is Content Delivery Netword, which is also known as “network accelerator” because CDN is an optimized network overlay to speed up network access speed.

The purpose of CDN?

1. Speed up access

CDN can enable users to obtain the required content nearby, reduce network congestion, and improve user access response speed and hit ratio.

It also provides server side acceleration to solve the problem of server overload caused by large user visits;

2. Achieve full network coverage across carriers and regions

The lack of interconnectivity, regional ISP geographic limitations, export bandwidth restrictions and other factors all cause the regional inaccessible websites.

CDN acceleration can cover lines all over the world. Through cooperation with carriers, IDC resources are deployed, and storage nodes are distributed on the edge of backbone nodes across the country. In this way, bandwidth resources are fully utilized and source traffic is balanced.

3. Keep your website safe

CDN load balancing and distributed storage technology, can strengthen the reliability of the site, quite virtually to your site to add an umbrella, to deal with most of the Internet attacks. Anti – attack system can also avoid malicious attacks on websites.

4. Remote backup

In the event of an unexpected failure of one server, the system will call on other nearby healthy server nodes to provide close to 100% reliability, allowing your site to never go down.

5. Cost savings

Can overcome the problem of uneven distribution of the website, the use of CDN to accelerate the implementation of the national website, you do not need to consider the purchase of servers and follow-up hosting operation and maintenance, mirroring synchronization between servers, also do not have to worry about the management and maintenance of technical personnel, and can reduce the site itself construction and maintenance costs.

6. Allows you to focus more on the business itself

CDN acceleration manufacturers generally provide one-stop services, which are not limited to CDN, but also supporting cloud storage, big data services, video cloud services, etc., and generally provide 7×24 operation and maintenance monitoring support to ensure that the network is smooth at any time, and you can rest assured to use it. And put more energy into developing its core business.

3. Application scenarios of CDN

1. Site/app acceleration

Dynamic files can be combined with cloud server ECS. Static resources such as various types of images, HTML, CSS, and JS files can be combined with object storage OSS to store massive static resources, which can effectively speed up content loading. Easily handle the website pictures, short videos and other content distribution

2. Video and audio on demand/large file download distribution speed

Support various file download, distribute, support online on demand to accelerate business, such as mp4, FLV video file or a single file size over 20 m on average, the main business scenario is the audio on demand, large file download (such as the installation package download), recommend object storage OSS use collocation, can speed back to the source, saving nearly two-thirds back to the source bandwidth costs.

3. Accelerated video live broadcast (in private test)

Live video streaming services, supporting media asset storage, slice transcoding, access authentication, accelerated content distribution integration solution. Adjust the server bandwidth in time to deal with the burst access traffic based on the elastic scaling service. Combined with media transcoding services, enjoy high-speed and stable parallel transcoding, and the task scale is seamless expansion. At present, CDN live broadcast has been accelerated for internal user testing and optimization, and will be launched soon

4. Mobile app acceleration

Mobile APP update file (APK file) distribution, mobile APP image, page, short video, UGC and other content optimization and accelerated distribution. Provides httpDNS services to avoid DNS hijacking and obtain real-time and accurate DNS resolution results, effectively shortening user access time and improving user experience

conclusion

The full name of the CDN is Content Delivery Network.

The basic idea is to avoid the bottlenecks and links that may affect the speed and stability of data transmission on the Internet as far as possible, so that the content transmission is faster and more stable. Through the server placed throughout the network node of a layer of intelligence on the basis of the existing Internet virtual network, CDN system can in real time according to the network traffic and each node connections, load condition and to the user’s distance and comprehensive information such as response time will the user’s request to guide users closest service node.

Its purpose is to enable users to obtain the required content nearby, solve the Internet network congestion, improve the response speed of users to visit the website.

Refer to the article

  • The front-end must know the CDN knowledge

  • Interesting about the CDN