Add share_groups quota

https://blueprints.launchpad.net/manila/+spec/add-share-groups-quota

Manila is able to create several different kinds of resources, which use real back-end resources. Since real resources are always finite, it is practical to have different kinds of limits/quotas for them. And one of not covered resources by limits is amount of share groups that user is able to create. Share Groups were added in Ocata timeframe and were, originally, consistency-groups in older than Ocata releases.

Problem description

The problem is in possibility to schedule creation of unlimited amount of share groups, that can lead to 2 bad things:

  • garbaging of DB with any amount of DB table records;

  • waste of real back-end resources.

So, implementation of quotas for share_group resource will solve above mentioned problems.

Use Cases

Control of used manila resources will now be more flexible, because admin will be able to set additional quotas for previously untracked manila resource.

Proposed change

Implement new quota resource called “share_groups” in existing quota mechanism. This quota will track amount of created share groups resources and restrict creation of them after limits are exceeded. Make default value be equal to amount of shares.

Alternatives

Do not implement quotas for share groups. In this case any user will be able to create unlimited amount of share groups.

Data model impact

Existing DB schema does not require any changes. Hence, no new DB migrations are required. We will reuse existing logic, where we can track any amount of resources by their names.

REST API impact

Only one (1) API will be changed, it is “quota-update”. It will be able to handle one more key provided in POST data, called “share_groups”. Also, “quota-show” command will return dict with quota resources [and usages] for this key too. Both these changes require bump of microversion and will be available only with this or later one microverisons. If for moment of this spec implementation share-groups feature stays ‘experimental’, then these API changes should be available only if ‘X-OpenStack-Manila-API-Experimental’ header provided and set to ‘true’ boolean value.

  • Update quotas

    • URL: /quota-sets

    • Method: PUT

    • JSON body:

      {
  'quotas': {
    'share_groups': 100,
  }
}

Driver impact

None

Security impact

None

Notifications impact

None

Other end user impact

Users will now be restricted in amount of share groups compared to previous behavior.

Manila client will have additional following optional key to “quota-update” command:

$ manila quota-update <tenant_id> --share-groups %amount_as_integer_value%

In general, quota should be able to be set to any value and in case usage exceeds current quota, request for creation of new resource will be refused.

Performance Impact

Resource usages will be checked each time we create/delete resources, but it is relatively cheap operation.

Other deployer impact

Deployers will be able to set quotas for share groups using either configuration file or “quota-update” API. It is optional possibility, not a mandatory action. New option will be named in the same way as all existing ones - “quota_share_groups”. It will accept only integer values.

Developer impact

None

Implementation

Assignee(s)

Primary assignee:

Work Items

  • Server side API changes, including unit and functional tests

  • Manila Client side changes, including unit and functional tests

  • Manila UI side changes, including unit tests

Dependencies

None

Testing

  • unit tests in ‘manila’, ‘python-manilaclient’ and ‘manila-ui’ projects

  • functional tests in ‘manila’ and ‘python-manilaclient’ projects

Documentation Impact

  • admin guide: add new ‘–share-groups’ parameter to ‘update-quota’ command.

  • devref: reflect the proposed change

References