tencent cloud

Overview

You can configure origin-pull rules for buckets in the COS console. If the object you request does not exist in the bucket, or a specific request needs to be redirected, you can configure origin-pull rules to access corresponding data via COS. Origin-pull configurations are mainly used for hot data migration, redirecting specific requests, and other relevant scenarios.

Note：

• The success rate of data origin-pull depends on your network environment.

Directions

1. Log in to the COS console.
2. Click Bucket List on the left sidebar.
3. Click the name of the bucket for which you want to set origin-pull.
4. Select Basic Configurations > Origin-Pull on the left, and click Add Rule.
   
5. In the pop-up window, configure the following information and click Next:

• Origin-Pull Condition: specify all conditions that must be met at the same time for triggering origin-pull.
  • HTTP Status Code 404: the only HTTP status code that triggers origin-pull currently. This option must be selected and cannot be cleared.
  • File name prefix: triggers the origin-pull rule when the requested file name matches this prefix. For example, if this field is set to prefix, origin-pull is triggered when you access https://examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/prefix123.jpg and an HTTP status code 404 is returned.
• Origin-Pull Protocol: the protocol used by COS to access the specified origin. The options include Force HTTPS, Force HTTP, and Follow request protocol.
  • If you select Force HTTPS or Force HTTP, COS will access the origin using HTTPS or HTTP respectively.
  • If you select Follow request protocol, COS will access the origin with the protocol used in the request.
• Request Parameter: specify whether to pass through the queryString request parameters carried when accessing COS to the origin.
• Request Header to Pass Through: specify the request headers you want to pass through to the origin.
• New Request Header: add the additional request headers to carry when COS accesses the origin.

6. Configure the following information and click Next:

• Origin-Pull Address: Enter the domain name or IP address without the http:// or https prefix. You can also add the port number after the domain name or IP address.

Example of a correct address:

abc.example.com
abc.example.com:8080
202.96.128.86
202.96.128.86:8080

You can configure a specific origin-pull address using the following fields:

• Fixed file: specifies a fixed file to which all requests are redirected when the origin-pull rule is triggered.
• Specified prefix: specifies the prefix for the file to which a request is redirected when the origin-pull rule is triggered. For example, if the prefix is specified as test, the request is redirected to <origin-pull address="">/test/prefix123. jpg when you access https://examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/prefix123.jpg, and the origin-pull rule is triggered.
• Specified suffix: specifies the suffix for the file to which a request is redirected when the origin-pull rule is triggered. For example, if the suffix is specified as .jpg, the request is redirected to <origin-pull address="">/prefix123.jpg when you access https://examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/prefix123, and the origin-pull rule is triggered.

Note：

• If you select Fixed file, the other fields cannot be used.
• Specified prefix and Specified suffix can be used at the same time.

• Standby Forwarding Address: When this option is enabled, you can add a backup origin. When the primary origin returns an error code such as 5xx, COS will access the backup origin.
• Sync Origin-Pull: When this option is enabled, COS will not return 3xx status code when pulling data from an origin. This option is currently available only for buckets in Beijing, Shanghai, Singapore, and Mumbai regions.
• 3xx Following Policy: If this policy is enabled, when your origin returns a 3xx redirect, COS will follow it to pull data from another origin.

7. Confirm that the configured origin-pull rule is correct and click OK.
   By default, COS always gives the highest priority to the most recent rule, by which it performs origin-pull. To change the priority manually, you can click the “Edit” icon under the “Priority” column in the rule list.
   

Example

Background
A user whose APPID is 1250000000 created a bucket named "examplebucket-1250000000", and enabled CDN acceleration endpoint domain name:

examplebucket-1250000000.file.myqcloud.com

Configure the origin-pull address of the bucket to be:

abc.example.com

Store the image picture.jpg at the origin http://abc.example.com.

First access by client (without sync origin-pull enabled):

http://examplebucket-1250000000.file.myqcloud.com/picture.jpg

When COS finds that the object cannot be hit, it returns HTTP status code 302 to the client and redirects to the following address:

http://abc.example.com/picture.jpg

First access by client (with sync origin-pull enabled):

http://examplebucket-1250000000.file.myqcloud.com/picture.jpg

When COS finds that the object cannot be hit, it returns the HTTP status code 200 to the client and redirects to the following address:

http://abc.example.com/picture.jpg

The origin then provides the object to the client to ensure access, and COS copies picture.jpg from the origin and saves it to the root directory of the bucket "example".

Second-time access:

http://examplebucket-1250000000.file.myqcloud.com/picture.jpg

COS directly hits the picture.jpg object in the root directory and returns it to the client.