Yandex Cloud CDN overview
Yandex Cloud CDN provides web service developers with a Content Delivery Network (CDN) functionality. The CDN servers located all over the world get content from your origins, cache the content, and deliver it to end clients on request. Thus you decrease the load on origins and reduce content waiting time for the end user.
How CDN works
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You keep your content in origins. As an origin, you can use your server with a domain name, an Object Storage bucket, or an L7 Application Load Balancer.
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In Cloud CDN, you create a resource and specify in its settings the origins, domain names for content distribution, and other CDN settings.
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Cloud CDN deploys CDN servers in many regions of the world and provides you with a domain name of the CDN Load Balancer that accepts requests and passes them to the servers. You must link this name to the domain names that you use for content distribution using the CNAME type of DNS records.
Note
Do not use an ANAME resource record with domain names for content distribution; otherwise, the end user will get a response from a CDN server not linked to the user's geolocation. The response will always be the same for all users.
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When the client requests a file using the domain name specified in the settings:
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Depending on where the client is located on the web, the CDN load balancer determines the CDN server that can deliver the content the fastest, and sends a request to this server.
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If the requested file is already cached on the selected CDN server, it's returned to the client right away. If the file is not cached, it is requested from one of the origins, cached (if caching on CDN servers is enabled), and also returned to the client.
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Service concepts
Cloud CDN uses the following concepts:
| Concept | Description |
|---|---|
| Resource | The main entity in the service that allows you to configure and control content distribution from origins over the CDN. |
| Origins and origin groups | The servers that are origins of content. CDN servers access them to load files. |
| Exchanging data between clients and the CDN | Receiving client requests by the CDN load balancer and sending response data from CDN servers. |
| TLS certificates | Certificates used for HTTPS connections between clients and the CDN load balancer. |
| CORS | Cross-domain client requests to the CDN (cross-origin resource sharing). |
| Content compression | Sending GZIP files to clients. |
| Exchanging data between the CDN and origins | CDN server requests for files from origins and responses to them. |
Host header |
Host HTTP header in CDN server requests to origins. |
| Content segmentation | Storing large files on CDN servers in parts. |
| Origin shielding | Using a shield server between CDN servers and origins to reduce origin load. |
| Redirecting requests | Redirecting requests from a CDN resource to an origin using the rewrite rule. |
| Content caching | Creating copies of files and storing them temporarily on CDN servers and/or on the client side. |
| Secure tokens | Setting up access to files on CDN servers based on time and IP using secure tokens. |
| IP-based access policy | Configuring access to CDN resources using an allow or block policy. |
| Log export | Exporting CDN and shielding server request logs to object storage. |
| Quotas and limits | Service use restrictions. |
See also the Yandex Cloud general resource hierarchy.