Smart Bay Scale Down
We currently allow Magnum to scale down bays by removing nodes from the Bay's ResourceGroup by updating the heat stack that created the bay. Example, to scale down a two-node bay to one node:
magnum bay-update k8sbay replace node_count=1
The problem with this approach is that Heat decides which node to delete, and all containers on that node will also be deleted. Let's make the selection process smarter, so that we ask Heat to delete (a) Bay node(s) that have NO CONTAINERS on them. This is possible by using the removal_policies property on the Heat stack with a resource_list identifying UUIDs of the Nova instance(s) to remove from the ResourceGroup when the count property is reduced.
Blueprint information
- Status:
- Complete
- Approver:
- Adrian Otto
- Priority:
- Low
- Drafter:
- Adrian Otto
- Direction:
- Approved
- Assignee:
- hongbin
- Definition:
- Approved
- Series goal:
- Accepted for liberty
- Implementation:
-
Implemented
- Milestone target:
-
liberty-2
- Started by
- hongbin
- Completed by
- hongbin
Related branches
Related bugs
Sprints
Whiteboard
Here is the documentation for the Heat ResourceGroup:
http://
Gerrit topic: https:/
Addressed by: https:/
Add 'host' field to Pod object.
Gerrit topic: https:/
Addressed by: https:/
Move conductor common implementations into module
Addressed by: https:/
Modify k8s template to support removal policy
Addressed by: https:/
[WIP] Implement bay smart scale down
Addressed by: https:/
Add documentation for smart scale down feature
Currently, smart scale down for k8s bay was implemented. I think we need to investigate how to introduce this feature to other bay types (separated BPs created for that).
Work Items
Dependency tree
* Blueprints in grey have been implemented.
