cinder-specs/specs/kilo/support-volume-backup-quota.rst

Support Volume Backup Quota

Include the URL of your launchpad blueprint:

https://blueprints.launchpad.net/cinder/+spec/support-volume-backup-quota

Provide a mean to control volume backup's quota.

Problem description

Since quota take volumes, snapshots and gigabytes into account, it also needs to take backup into account:

• Currently Backup create API is not an admin API, users of projects could create any number of backups.
• If some evil users create many more big backups to exhaust the free space of backup storage back-end, it would cause cinder-backup in the state of rejecting service.

Use Cases

Proposed change

By supporting volume backup quota, we need to do the following changes.

• Add the default quota of backup number quota item and backup gigabytes quota item.

• Cinder quota update API support backup number quota and backup gigabytes quota create and update operation.

• Cinder quota show/defaults API support displaying backup quota info.

• Quota Engine support processing with backup quota item.

  Class QuotaEngine and Class VolumeTypeQuotaEngine support processing
  with backup quota item.
  Add _sync_backups function to get one project's backup number.
  Add _sync_backup_gigabytes function to get one project's backup
  gigabytes number.
  Add configuration item no_backup_gb_quota, which indicates whether to
  take backup's size into account with backup gigabytes quota.
  Add '_sync_backup': _sync_backups to QUOTA_SYNC_FUNCTIONS.
  Add '_sync_backup_gigabytes': _sync_backup_gigabytes to
  QUOTA_SYNC_FUNCTIONS.

• Backup create/delete routine support dealing with backup number quota and backup gigabytes quota.

• Limits API support displaying one project's current used number and maximum number of backup number and backup gigabytes info.

Alternatives

None

Data model impact

None

REST API impact

Change the following APIs' return value.

• Cinder quota show/defaults API

  • Current return value:

    {
        "quota_set":
        {
            "gigabytes": 1000,
            "snapshots": 10,
            "volumes_rbd": -1,
            "volumes": 10,
            "gigabytes_rbd": -1,
            "snapshots_rbd": -1,
            "id": "bb2ec78e61d3493da61449f3c69db3f3"
        }
    }

  • New return value:

    {
        "quota_set": {
            "gigabytes": 1000,
            "snapshots": 10,
            "volumes_rbd": -1,
            "volumes": 10,
            "snapshots_rbd": -1,
            "gigabytes_rbd": -1,
            "backups": 10,          # new add return item
            "backup_gigabytes": 1000, # new add return item
            "id": "bb2ec78e61d3493da61449f3c69db3f3"
        }
    }

• Limit index API return value

  • Current return value:

    {
        "limits": {
            "rate": [],
            "absolute": {
                "totalSnapshotsUsed": 0,
                "maxTotalVolumeGigabytes": 1000,
                "totalGigabytesUsed": 5,
                "maxTotalSnapshots": 10,
                "totalVolumesUsed": 5,    #new add return item
                "maxTotalVolumes": 10     # new add return item
            }
        }
    }

  • New return value:

    {
        "limits": {
            "rate": [],
            "absolute": {
                "totalSnapshotsUsed": 0,
                "maxTotalVolumeGigabytes": 1000,
                "totalGigabytesUsed": 5,
                "maxTotalSnapshots": 10,
                "totalVolumesUsed": 5,
                "maxTotalVolumes": 10,
                "totalBackupsUsed": 0,       # new add return item
                "maxBackupsUsed": 10,        # new add return item
                "totalBackupGigabytesUsed": 0, # new add return item
                "maxTotalBackupGigabytes": 1000, # new add return item
            }
        }
    }

Security impact

DoS via resource exhaustion of backup resources is prevented.

Notifications impact

None.

Other end user impact

The return values of Cinder quota show/defaults API and limits API have changed.

Performance Impact

None

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:

ling-yun<zengyunling@huawei.com>

Work Items

• Implement code that mentioned in "Proposed change".
• Add change API doc.

Dependencies

None

Testing

Both unit and Tempest tests need to be created to cover the code change that mentioned in "Proposed change" and ensure that Cinder Quota feature works well while adding support for volume backup.

Documentation Impact

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

References

None