You can set back-to-origin rules to define whether to retrieve origin data by mirroring or redirection. Back-to-origin rules are usually used for hot migration of data and redirection of specific requests. You can configure up to five back-to-source rules, which are executed in sequence.

Back-to-origin does not support intranet endpoint. 


  1. Log on to the OSS console .
  2. Click one of the bucket names on the left.
  3. Click Basic Settings, locate Back-to-Origin area, and click Edit.
  4. Click Create Rule
  5. Select Mirroring or Redirection.
    • If you choose Mirroring and a requested file cannot be found on OSS, OSS will automatically fetch the file from the origin, save it locally, and return the content to the requester.
    • If you choose Redirection, OSS redirects requests that meet the prerequisites to the origin URL over HTTP, and then a browser or client returns the content from the origin to the requester.
  6. Set Prerequisite and Origin URL. In the Mirroring mode, you can choose to enable Transfer queryString or not. In the Redirection mode, you can set Redirection Code.
  7. In the Mirroring mode, you can set the transmission rule of HTTP header.

    The configuration example is as follows:

    If the HTTP header in a request that sent to OSS is as follows:
    GET /object
    host :
    aaa-header : aaa
    bbb-header : bbb
    ccc-header : 111
    After the back-to-origin is triggered, the request that OSS sends to the origin is as follows:
    GET /object
    host :
    aaa-header : aaa
    ccc-header : ccc
    The following HTTP headers do not support transmission rules:
    • The headers with the following prefixes:
      • x-oss-
      • oss-
      • x-drs-
    • All the standard HTTP headers, such as:
      • content-length
      • authorization2
      • authorization
      • range
      • date
  8. Click OK.
After the rule is saved, you can view the configured rule in the rule list and perform corresponding Edit or Clear operations.