What is the Best Practice to Delete Objects and Deal with Versioning?¶
In OBS buckets are containers, with their names acting as globally unique identifiers, thus two buckets in the OTC can't share the same name. The objects stored in these buckets however are identified by their unique IDs, which allows overloading objects with newer versions, under the same name, if versioning has been enabled for the bucket. (for more information about versioning see Versioning, How Do I Use Versioning?).
There is no limit to the number of versions, however from experiences of running versioning in a productive environment we found that listing versioned objects can easily run into difficulties. To avoid performance issues we don't recommend to list all objects in buckets with versioning either enabled or suspended. As the OTC console depends on listing all objects as well, it is also highly recommended not to rely on it in managing versioned objects.
Some tools like OBS browser currently also can't handle versioned objects and will only list and manipulate the current version of the object.
Right now the recommended method for managing versioned objects is using SDK or API directly (for more information see Listing Objects API request syntax for multi-version objects and Versioning for Downloading Objects API request).
Typical Use Cases¶
A typical use case is recovering the latest historical version of an object by deleting the deletemarker version. This operation is recommended to be performed either through API or SDK. This is a single operation based on the specific object ID. For more information see Versioning for Deleting an Object API request.
Another typical use case is deleting all versions of objects with a specific name (or even all objects from a bucket to delete the bucket). This operation however would need to be performed on multiple objects and thus can again run into difficulties based on the number of objects. It is recommended in this case to limit the batches of objects the operation runs on at the time and also the number of concurrency. For more information see Deleting Objects.
Configuring Lifecycle Rule for Mass Deleting Objects¶
The best practice for mass deleting objects (regardless of versioning) is using Lifecycle Rule.
To conveniently delete a large number of objects you can configure a Lifecycle Rule (see Configuring a Lifecycle Rule) that will remove these objects after the specified number of days - the Rule will be applied either to some of the objects based on a prefix or to all objects in the bucket. In order to configure such rule:
In the bucket list, click the bucket you want to operate. The Overview page of the bucket is displayed.
In the Basic Configurations area click Lifecycle Rules. The Lifecycle Rules page is displayed.
Click Create. The Create Lifecycle Rule window is displayed.
In the Basic Information section:
Enter Rule Name.
Enter Prefix if necessary (for example if you want to only delete files from some specific folder called folder_name, you can specify "folder_name/" as a prefix).
If you want to delete all files from the bucket select Bucket in the Applies To switch.
In the Current Version (for the current version of the multi-version object) and Historical Version (for all other versions of the object) sections:
Select Configure now in the Expiration Time switch.
Enter the number of days after which a file should be removed in the Delete After edit field (minimum value - 1 day).
Click OK.