CDN is capable of configuring basic cache. Cache validity can be configured according to rules such as specified service types, directories, and specific URLs to regularly purge resources cached on nodes, pull the latest resources from the origin server, and cache them again.
In addition, CDN can purge cache for specified URLs or directories in batches:
Last-Modify information of the resource will be pulled from the origin server. If it is the same as that of the cached resource, the cached resource will be directly returned; otherwise, the updated resource will be pulled from the origin server and cached again. If you select Purge all resources, when the user accesses a resource under the corresponding directory, the latest version of the resource will be directly pulled from the origin server and cached again.
After a purge is successfully executed, the corresponding resource on the node will not have a valid cache. When the user initiates an access request again, the node will pull the required resource from the origin server and cache it on the node. If you submit a large number of purge tasks, many caches will be cleared, resulting in a surge in origin-pull requests and high pressure on the origin server.
When a resource is overwritten by a new resource with the same name on the origin server, you can submit a request to purge the URL/directory and clear all caches so users can directly access the latest version of the resource. This will prevent users from accessing the legacy version of the resource cached on the node.
When illegal resources (such as resources related to pornography, drug, or gambling) are found on your origin server, they may still be accessible even after you delete them on the origin server because of node cache. To protect your network environment security, you can delete the cached resources through URL purge.
Log in to the CDN console, click Purge and Prefetch on the left sidebar, and submit a Purge URL or Purge Directory task:
Check whether the submitted content meets the following specifications:
http://www.test.com/test.html, and should be entered one per line.
When you are running out of daily purge quota, you can increase it on your own in the Tencent Cloud CDN console.
- The new quota will take effect immediately. The page will be refreshed automatically. You don’t need to click the refresh button frequently.
- Each quota can only be increased once a day.
- Each quota is increased independently for each region.
By default, URLs will be purged by acceleration regions of domain names in the URLs. If the domain names are accelerated globally, quotas for regions both in and outside the Chinese mainland will be consumed.
To query your operation records, please see History.
URL purge, directory purge, and purge history query have been integrated within the permission system which supports permission configuration at the resource (domain name) level. For more information, see Console Permissions.
The acceleration domain name is
purge-test-1251991073.file.myqcloud.com, the origin server is Tencent Cloud Object Storage (COS), and resources on the origin server are as follows:
2.txt respectively. Nodes to be hit can be determined based on
X-Cache-Lookup: Hit From Disktank3 and
Server: NWS_SPMid, resources will be directly returned by the nodes:
1.txt with a file that has the same name, and the file’s last modified time changes, while
2.txt stays the same:
1.txt resource will be accessed:
1.txt has been changed, the request will be forwarded to the origin server. As
2.txt has not been changed, even after a directory purge task is submitted, it will still be hit and returned: