The object chunking feature enables Dynamic Route for CDN (DCDN) to retrieve resources from the origin server based on HTTP range requests. The origin server then returns partial content within the specified range, which helps to accelerate delivery of large files. This feature helps to reduce the back-to-origin data usage and shorten the resource response time. This topic describes how to configure object chunking.

Background information

Make sure that the origin server supports HTTP range requests. If the HTTP request header contains the range field, the origin server must be able to return 206 Partial Content.

Procedure

  1. Log on to the Dynamic Route for 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 Configure.
  4. In the left-side navigation pane of the specified domain, click Origin Fetch.
  5. In the Range Origin Fetch section, click the Range Origin Fetch switch to enable or disable object chunking.
    Object chunking Description Example
    Enabled To access the specified part of a resource file, enable object chunking to improve resource response efficiency. When DCDN receives a byte-range request and cannot return the requested resources from the cache, it forwards the request with the range field to the origin server. When the origin server receives the request, it returns a file that has the specified number of bytes based on the range field. DCDN then returns the file to the client. A client sends a request that contains range:0-100 to DCDN. DCDN forwards the request to the origin server with range:0-100. Based on the range field, the origin server returns a file with 101 bytes in the range of 0 to 100 to DCDN. DCDN then returns the file to the client.
    Disabled To access all the content of the resource file, disable object chunking. When DCDN receives a byte-range request and cannot return the requested resources from the cache, it forwards the request without the range field to the origin server. When the origin server receives the request, it returns the entire file to DCDN. DCDN then returns the requested range to the client. After the client receives the requested range, it automatically disconnects the HTTP connection from DCDN. As a result, the file returned from the origin server is not cached on DCDN. This reduces the cache hit ratio and increases the back-to-origin data usage. A client sends a request that contains range: 0-100 to DCDN. DCDN forwards the request to the origin server without the range field to request the entire file. Then, the origin server returns the entire file to DCDN, and DCDN returns 101 bytes to the client based on the range field. When the client receives the requested range, it disconnects from DCDN, which disables DCDN from caching the file returned from the origin server.
    Object chunking