Backup Force Delete API

https://blueprints.launchpad.net/cinder/+spec/support-force-delete-backup

Provide an API to force delete a backup being stucked in creating or restoring, etc..

Problem description

Currently there are volume force-delete and snapshot force-delete functions, but there is not a force-delete function for backups. Force-delete for backups would be beneficial when backup-create fails and the backup status is stuck in ‘creating’. This situation occurs when database just went down after backup volume and metadata and update the volume’s status to ‘available’, leaving the backup’s status to be ‘creating’ without having methods to deal with through API, because backup-delete api could only delete backup item in status of ‘available’ and ‘error’.

Use Cases

If backup create successfully in object storage, but become stuck in update backup’s status because database just went down. Then use force-delete API, we could directly delete the backup item(include all the stuff in storage backend and db entry info) without manually change the backup’s status in db to error or restart cinder-backup and call backup-delete function, which is very useful for administrators.

Proposed change

A new API function and corresponding cinder command will be added to force delete backups.

The proposal is to provide a method for administrator to quickly delete the backup item that is not in the status of ‘available’ or ‘error’.

  • It’s an admin-only operation.

Alternatives

First, login in the cinder database, use the following update sql to change the backup item status to ‘available’ or ‘error’.

update backups set status=’available’(or ‘error’) where id=’xxx-xxx-xxx-xxx’;

Second, call backup delete api to delete the backup item.

Data model impact

None

REST API impact

Add a new REST API to delete backup in v2:: *POST /v2/{tenant_id}/backups/{id}/action

{
“os-force_delete”: {}

}

Normal http response code:
202
Expected error http response code:
404

Security impact

None

Notifications impact

Delete notification should include whether force was used or not

Other end user impact

A new command, backup-force-delete, will be added to python-cinderclient. This command mirrors the underlying API function.

Force delete a backup item can be performed by: $ cinder backup-force-delete <backup>

Performance Impact

None

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:
ling-yun

Work Items

  • Implement REST API
  • Implement cinder client functions
  • Implement cinder command

Dependencies

None

Testing

Need to test the force delete with an in-progress backup and ensure that it deletes successfully and cleans up correctly.

Documentation Impact

The cinder client documentation will need to be updated to reflect the new command.

http://docs.openstack.org/admin-guide/blockstorage-manage-volumes.html

The cinder API documentation will need to be updated to reflect the REST API changes.

References

None