Details about Aliyun CDN:
Ali Cloud CDN use tutorial
(CDN can distribute the content of the source station to the node closest to the user, so that the user can obtain the required content nearby and improve the response speed and success rate of user access. Solve the problem of access delay caused by distribution, bandwidth, server performance, suitable for site acceleration, on-demand, live and other scenarios.
CDN application scenarios
Web site/application 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 distribute pictures, short videos and other content on the website
Architecture diagram
Video and audio on demand/large file download distribution acceleration
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.
Architecture diagram
Live video acceleration
Aliyun one-stop live video service has been officially launched! Based on the leading content access and distribution network and large-scale distributed real-time transcoding technology, the audio and video live broadcasting platform provides convenient access, high-definition fluency, low latency, and high concurrency audio and video live broadcasting services. Support multiple live scenes, panoramic data statistics, rich Angle analysis; Live features rich, recording playback, real-time cover, real-time transcoding, even wheat mixed flow.
Architecture Diagram Live architecture diagram
Mobile application acceleration
Mobile APP update file (APK file) distribution, mobile APP images, pages, short videos, UGC and other content optimization to accelerate distribution. Provides the httpDNS service to avoid DNS hijacking and obtain real-time and accurate DNS resolution results, shortening user access time and improving user experience.
Architecture diagram
CDN noun explanation
The domain name
A domain name is the name of a server or a network system on the Internet, all over the world, there is no duplicate domain name
CNAME record
It is an alias record (Canonical Name); When the DNS queries the name on the left of the CNAME, the DNS searches the name on the right of the CNAME until the last PTR or A name. The DNS responds only after the query succeeds. Otherwise, the DNS fails.
CNAME domain name
CNAME record is required for domain name acceleration of CDN. After configuring CDN acceleration on Ali Cloud Console, you will get an accelerated domain name, called CNAME domain name (the domain name must be *.kunlun.com), users need to point to this domain name as CNAME. The domain name resolution work will officially shift to Ali Cloud, all requests for this domain name will be directed to the nodes of Ali Cloud CDN.
DNS
The DNS is the Domain Name System. Its role in the Internet is: the domain name into the network can recognize the IP address. People used to remember domain names, but each machine only recognize IP addresses, domain names and IP addresses are one-to-one correspondence between them, the translation work is called domain name resolution, domain name resolution needs to be completed by a special domain name resolution server, the whole process is automatic.
For example, the input www.baidu.com will be automatically converted to 220.181.112.143
Edge node
Also called CDN node, Cache node, etc. It is a concept proposed relative to the complex structure of the network. It refers to the network nodes with fewer intermediate links from the access of the end users, which have better response ability and connection speed to the end users. Its function is to store the contents and objects of the most visited pages in the dedicated cache device at the front of the server, so as to improve the speed and quality of website access.
Back to the source host
Back to source host: The back to source host determines the specific site on the source site that the back to source requests to access.
Example 1: If the source site is the domain name, the source site is www.a.com, and the return source host is www.b.com, the actual return source is the IP address resolved by the request to www.a.com, and site www.b.com on the corresponding host
Example 2: If the source IP address is 1.1.1.1 and the source host is www.b.com, the actual source IP address is www.b.com on the host corresponding to 1.1.1.1
That is, if the client requests resources in HTTPS mode and the CDN does not cache the resources, the CDN uses the same HTTPS mode to retrieve resources from the source. Similarly, if the client uses HTTP to request, the CDN node also uses HTTP to return to the source.
Filter parameters
The filter parameter is used when a URL request contains? And when the request with parameters is sent to the CDN node, whether the CDN node requests the request URL with parameters back to the source station after receiving the request. If the filtering parameter is enabled, the request will be intercepted to the URL without parameters after reaching the CDN node to request the source station. And only one copy of the CDN node is kept. If this function is turned off, each different URL caches a different copy on the node of the CDN.
Use the sample
For example, http://www.abc.com/a.jpg?x=1 requests the URL to the CDN node. After the Filter parameter function is enabled, the CDN node sends a request to the source station http://www.abc.com/a.jpg (ignore the parameter x=1). After the source station responds to the request, the CDN node keeps a copy after the response reaches the CDN node. Then proceed to respond to the terminal with the contents of http://www.abc.com/a.jpg. All similar requests for http://www.abc.com/a.jpg? Parameters respond to the contents of a CDN copy http://www.abc.com/a.jpg. If “Filter parameters” is disabled, each different URL will cache different copies on the nodes of the CDN. For example, http://www.abc.com/a.jpg?x=1 and http://www.abc.com/a.jpg?x=2 respond to the response content of the source site with different parameters.
Official website of Ali Yun University (Official website of Ali Yun University, Innovative Talent Workshop under cloud Ecology)