This topic describes how to configure object chunking in the Alibaba Cloud Content Delivery Network (CDN) console and the usage notes. The object chunking feature reduces the amount of network traffic generated during the back-to-origin process and the response time. This feature facilitates the delivery of large files.

Background information

The object chunking feature specifies that the origin server returns only specified file chunks to clients.

When you configure object chunking, take note of the following items:
  • Make sure that the origin server supports HTTP requests that contain the Range field, and the origin server can respond to requests with the 206 HTTP status code (partial content message).
  • Object chunking is optional and is disabled by default.

Procedure

  1. Log on to the Alibaba Cloud CDN console.
  2. In the left-side navigation pane, click Domain Names.
  3. On the Domain Names page, find the target domain name and click Manage.
  4. In the left-side navigation pane of the specified domain, click Video.
  5. In the Object Chunking section, click Modify.
  6. Set Object Chunking to On, Off, or Force.
    Value Description Example
    On If you want the origin server to return only the specified chunks of files, you can select this value to enable object chunking. This feature increases content delivery efficiency. After you enable this feature, the origin server determines the chunks of files to be returned based on the Range header field in the request. The CDN node also returns the file chunks determined by the origin server to the client. If a client sends a request that contains range:0-100, the requests is redirected to the origin server with range:0-100 retained. The origin server returns a file chunk that contains 101 bytes to the CDN node based on the Range header field. The CDN node then returns the file chunk to the client.
    Off If you want the origin server to return the entire files to clients, select this value to disable object chunking. After you disable this feature, CDN nodes retrieve the entire files from the origin server. The HTTP connection between the client and CDN node automatically closes after the client receives the requested file. The file is not cached on the CDN node. Therefore, the cache hit ratio decreases and the amount of network traffic generated during the back-origin process increases. If a client sends a request that contains range:0-100, the request is redirected to the origin server with range:0-100 ignored. The origin server returns the entire file that contains 101 bytes to the CDN node based on the Range header field. The HTTP connection between the client and CDN node automatically closes after the client receives the file. Therefore, the file is not cached on the CDN node.
    Force If you want all requests that contain the Range header field to be redirected to the origin server, select this value. If you set Object Chunking to Force, make sure that the origin server supports the Range header field.
    Note When you set Object Chunking to Force, all chunked requests are forcibly sent to the origin server.
  7. Click OK.