f350472e62
This moves the completed queens specs to the implemented directory, adds the redirects and also removes the queens-template symlink from the approved directory and docs. This was done using: $ tox -e move-implemented-specs -- queens Change-Id: I9e4d9aec4a1ced181ef7850627b9c67de376beae
3.5 KiB
Enable cold migration with target host - Queens
https://blueprints.launchpad.net/nova/+spec/cold-migration-with-target-queens
The aim of this feature is to let operators cold migrate instances with target host manually.
Problem description
A target host can be specified on the live migration operation. But a target host cannot be specified on the cold migration operation. It is inconsistent with the live migration operation, and both of these operations have similar circumstances when the host needs to be specified.
Use Cases
It is same as the live migration use case. Sometimes an operator or a script decides which host is the best suited to accept a cold migration and then wants to perform it. Consistency with a live migration case should be ensured.
Proposed change
Modify the API and the current resize_instance flow to be able to specify the target host for cold migration.
Add the function to check whether a destination host is in accordance with scheduler rules or not in cold migration as a default behaviour. Specifically to say, add setting 'requested_destination' of the RequestSpec object in nova/compute/api.py. The field has already been supported in the scheduler, so it just needs to be filled in.
Alternatives
None
Data model impact
None
REST API impact
URL: POST /v2.1/servers/{server_id}/action
JSON request body:
{ "migrate": { "host": "target-host" } }
The 'host' parameter to specify a target host is optional. Microversion is bumped up.
Security impact
None
Notifications impact
None
Other end user impact
python-novaclient will be modified to have a target host argument as optional.
nova migrate <server> [<host>]
Performance Impact
None
Other deployer impact
None
Developer impact
None
Implementation
Assignee(s)
- Primary assignee:
-
natsume-takashi
Work Items
- Add logic to specify target host for cold migration
- Add processing checking destination host in the cold migration
- Disable retries of the scheduling when the target host is specified
- Add API with bumping a new microversion
- Add nova functional tests
- Add tempest tests
Dependencies
None
Testing
Add the following tests.
- Unit tests
- Functional tests
- Tempest tests
Documentation Impact
- API Reference
- CLI Reference
- Admin User Guide on cold migration topic.
References
Mailing list discussion about why force flag is not
added as part of this proposal: http://lists.openstack.org/pipermail/openstack-dev/2017-August/121654.html
History
The blueprint has been approved for Ocata as 'cold-migration-with-target-ocata' and for Pike as 'cold-migration-with-target-pike'. It is renamed to 'cold-migration-with-target-queens' now. But the 'force' parameter to bypass the scheduler check is removed in the spec.
| Release Name | Description |
|---|---|
| Ocata | Approved |
| Pike | Reapproved |
| Queens | Reproposed |